^\^-:iv;i^ r-=ae;Ss^?»>*_.' , ;,''^^i)i< THE ANATOMY O F T H E Human Body. With XXXIV Copper-Plates, BY W. CH E S E L D EN, Surgeon to St. Thomas' s -Hosv it m.^ And Fellow of the Royal Society. Of all God's Works that do this World adorn^ 'There is not one more fair and excellent^ Than is Man's Body loth for Power and Form. Spenser. The Third Edition. L 0 N B O N, Printed by W. Bowyer: And fold by ^ames and John Knapon^ J. and B. Sprwt^ 3- Oshorn and T, Lon^man^ J. Noofs^ J. Biilingsiey^ J. Woodynan and jD. Loyon^ of Lo«^(?;i?, Book fellers j ^ndi A^ Ramfey o^ Edinburgh, MDGCXXVL ' HARVARD UNIVERSITY SCHOOL OF MEDICINE AND PUBLIC HEALTH LIBRARY • 13 JUL] 933 .^-i ,. , TO Dr. Richard Mead, F E L L o \tr of the College of Phyficians in Lo n d o n. And Fellow of the ROYAL SOCIETY. SIR, VERY part of P H Y s I c K may juftly prefume on your protec- tion^ to whom it owes fo A 2 much The Dedication. much improvement. A- N A T o M Y in particular has received fuch ad- vantage from your Lec- tures, that it were a kind of injuflice not to dedicate all endeavours in that way to you -, in me indeed it would be un- pardonable not to offer the fruits of thofe ilu- dies, which at firfl be- gan, and have flill been carried on with vour en- couragement. The kind reception my indullry has met with, is owing to you, the authority of whofe o- pinion The Dedication. pinion has in every place iecured me fo much fa- vour ^ efpecially in that feat of learning, which with diflinguiflied ho- nours rewarded your me- rit. I am, SIR, Tour mofl oWged and^ ohdjent humble Servant, W. C H E S E L D E N* Digitized by the Internet Archive in 2011 with funding from ♦ Open Knowledge Commons and Harvard Medical School http://www.archive.org/details/anatoniyofhumanbol726ches THE PREFACE. HIS treatlfe being de- ftgned for the ufe ofthofe who fiudy Anatomy, I have d'lfpofed it in the fame order in which it is uj taught. The hones firfl ^ and then the mufcles ^ hecaufe the kmwledg^e of the bones is necejfav^ to the know- ledge of the mufcles'^ and afterwards the vejfelsy becaufe their fituation^ • ■ A 4 are The Preface. are chiefly defcrlhed by the bones and mufclesy near which they are fittiated. But before we jhew the vejfels m the limbs ^ we find tt necejfary to Jhew the parts in the three cavities ^ which I have endeavoured to do in that or- der which is mofl convenient to dif- feci iny and fitteji for the explana- tion of the animal qeconomy ; But the parts of generation ^ and the . five fenfes^ being fit to be conftdered fe- parately^ they are all done in a di- flinB book. IN defcribing of the parts ^ I have pretty much negleSed the Minuti^ in Anatomy: Nor ]oave I been very particular about thofe ^ things which cannot be underfiood without being feen^ and being feen need little defcription 5 but have endeavoured to .8 he The Preface. be more ,expkctt ahot44, thofe which are ofgreatefi ufem Philosophy, .Physic, aud Surgeuy: And I could zvijh the dtvtdmg and dtfim-- gf/t/hmg of parts were ufually done with more regard to thefe valuable ends. I MUST here acknowledge my ohllgattons to Mr. Monro, profejfor 328 and 334 THE THE ANATOMY O F T H E Humane Body. Tloe General IntroduBton. IT is a received opinion, that an animal body is, a Compages of vefTels , vari- oufly difpofed, to form parts of diife' rent figures, for different ufes. The ancients fuppofed, that the heart and brain were lirfl: formed, and that all the other parts proceeded from them, and that all mem.branes were derived from the Dura Mater, or Pia Mater of the brain. They di- ftinguifhed all the parts into fpermatic and fan- B guineous. The General IntroduBion. guineous ; and frequently engaged themfelves in difputes about the derivation of parts ; with many other things, of the like nature, confequences of their Hypothefis. But the moderns, aflifted with glafles, have difco- vered, that all the parts exift iii miniature, from the firft formation of the Fcetus •, and that their increafe, is only the extenfion and thickning of their veflels, and that no part owes its exiftence to another. Thus much I thought neceffary to pfe- mife, that the reader might have a general idea of the body, and that he may fee for what reafon no notice is taken in this treatife of fome diftindlions and divifions of parts, tifed by ancient Anatomills , and thofe who have copyed after them. The confiituent parts of the animal bo- dy, are. Fibres, Membranes, Arteries, Veins, Lymphs^duds , Nerves, Glands, Excretory YeiTels, Mufcles, Tendons, Ligaments, Car- tilages and Bones-, to thefe may be added the Hair and Nails, though they feem to have only a vegetative kind of life. Fi B.R E s, as they appear to the naked eye, are fimple threads of the minuteft blood vef- fels or nerves, or both, which enter into the compofition of every part. Membranes, are Compages of fibres, expanded, to cover, or line any other part. '*» The Wm The General Introduci'ton. 3 "m The arteries, are tubes that arife in two trunks from the two ventricles of the heart, and thence dividing, into branches, dillribute the blood to every part of the body. Veins, are tubes to return the blood from the extremities of the arteries to the heart* Lymph^educts, are pellucid tubes to carry lymph from all parts, efpecially the glands, which they difcharge into the larger veins, and into the Vafa Ladea. N E Rv E s are Fafciculi of cylindrical fibres, which arife from the Medulla Oblongata of the brain, and the Medulla Spinalis, and ter- minate in all the fenfitive parts. They are the immediate organs of fenfation* A Gland fecretory, is compofed of an artery, vein, lymphatic, excretory du6t, and nerve. The ufe of glands is to fecrete fluids from the blood for feveral ufes. E X c R E T o R y-Ve s s e L s, are either tubes from glands to convey the fecreted fluids to their refpedlive places, or veflels from the fmall guts, to carry the chyle to the blood- Veflels ; thefe lafl:, are call'd Vafa Ladlea. Muscles, are dillindl portions of flefh, which, by contrading, perform the motion^ of the Body. Te^jiSons, are the fame fibres of which the mufcles are compofed •, but white and more clofely connected^ that they may poflefs lefs B t ipacg The General IntroduBton, *»\* III ' " "■■ *" ' i- ■*«» fpace in a limb, and be inferted in lefs room into a bone. Ligaments, are ftrong membranes, or bodies of fibres clofely united, either to bind down the tendons, or give origin to the muf- cle5, or tie together fuch bones as have motion. Cartilages, or griflles, are hard, ela- ftic, fmooth and infenfible : Their ufe is to cover the ends of the bones that have motion, to prevent their attrition, &c. Bones, are firm parts to fuftain, and give fhape to the body. The hair and nails are fufHciently known ; the former feemsto be nourilhed from the Ma- teria Perfpirabilis , and the latter from the Reticulum Mucofum, betwixt the Cutis and Cuticula. BOOK BOOK I. C H A P. I. IntroduB'ton to the Bones. THE life of the bones is to give fhape and firmnefs to the body, to be le- vers for the mufcles to adl: upon, and to defend thofe parts from external inju- ries that are of greatefl confequence to be preferved, as the brain, heart, &c. They are in theh- firftftate veryfoft fibres, till by the addition of a matter, whfch is fe- parated from the blood into them, they grow by degrees to the hardnefs of a cartilage, and then perfe6l bone : But this great change is neither eifedied in a very fhort time , nor begun in all the parts of the fame bone at once. Flat bones, that 'have their fibres diredled to all fides, begin to offify in a middle point; but thofe that have their fi-T^b.v.C. bres nearly parallel, begin in a tranfyerfe middle line, that is in the middle of each B 3 fibres IntroduBton to the Bones. fibre ; and fo the cylindrical bones in a mid- dle ring, from which they Ihoot forth to their extremities. By the continual addition of this oilifying matter, the bones increafe, till their hardnefs refills a farther extenfion , and be- Caufe their hardnefs is always increafmg while they are growing, the increafe of their growth becomes flower and flower, till they ceafe to grow at all ; and at length in old or weak perfons, if I anri not miftaken in my obfer- vations, they decreafe as v/ell as the ?it^^ parts, though not fo fail, by reafon of their hardnefs. And though I think it would be difficult to prove this, yet the poflibility of it at leaft will fufficiently appear from the following cafe. A foldier that from a fhot in his left groin, had the head of the Os Fe- moris broke, part of which came away through the wound, upon which the limb wafled, and he dying of an Anafarca about a year after, I found the Os Femoris wafled about an inch in length, but fo much in its thicknefs, that when they were both dried and fawed length- ways through their middles, the emaciated bone weighed thirty grains lefs than half the weight of the other thigh bone : From the ap- pearance of this man, and the firm connexion of all the bones with their Epiphyfes, I am perfuaded he mufl have done growing befdre he receiv'd this wound j therefore^ unlefs he was IntroduBton to the Bones, 7 was taken lame into the fervice, which can^ not be fuppofed, this bone muil4iave wafted about thus much in that time. The oITifying matter of the bones is fo well diredied to them by fome wife law, that I have feen but one inftance of a bone in an adult body un- ofTified, which was fo much of one fide of the lower jaw as is beyond the teeth ; but Tab. vi. bony excrefcences upon the bones are fre-^*^- quent, and even the flelhy parts, efpecially in old perfons, are fometimes olTified. In' an old man that died of a mortification in his leg, I found all the arteries of the legs bo- . ny, efpecially between the divifions of the branches, and many parts of the Aorta. But the moft confiderable inftance of this kind that I have ever found, is in part of the muf- cular fibres of the heart of a man, nearer its Vertex than the bafe, as large as a fixpence, perfedly ofTified. And though it might feem that the bones, while they appear cartilagi- nous, differ from perfeft bones oaly in hard- nefs , yet in a child two years old that I kept in vinegar, all the bones grew near as foft and pliable as the flefhy parts, though the fkin in feveral places was not taken off"; yet the cartilages and cartilaginous Epiphy- fes of the bones were but little altered. Bones that are without motion, as thofe of the fcull, the Oifalnnominata, &c» alfo bones B 4 wiih 8 IntroduB'ton to the Bones, with their Epiphyfes, when they meet, prefs into each OPther, and form futures, which foon difappear in thofe that join, while their olTific matter is foft ; but thofe that grow harder before they meet, prefs more rudely into each other, and make more uneven fu- tures, fome of which in the fcull endure to Tab.iii. the greateft age; and very often the oiTific ^* ^' matter not flowing far enough to complete a bone, the part uncompleted has an oiiifica- tion begun in its center, and is formed into a diilind bone, which may happen to be of , any figure. Thefe bones are ofteneft found in Tab. iii. the lambdoidal future , and are called OlTa ^9- Triquetra. But the ends or fides of bones that are intended for motion, are hindered from uniting, by the cartilages which cover them ; for wiien thefe cartilages are deilroyed Tab vi E ^'^^1 very readily unite ; this diftemper is called Ancylofis. The ends of all the bones that are articu- lated for very manifeil motions, or that are not placed againft other bones, are tipped with Tab. V. Epiphyfes , or additional bones , which in i> i« 3* fome meafare determine their growth and fi- gure ', for if they had nothing to give bounds to them, they would fhoot oat like the Cal- lus from the broken ends of a bone that is not fet, and grow more ragged than the edges of bones which are joined by futures \ and fometimes IntroduBton to the Bones. fometimes Epiphyfes are made ufe of to raife procefTes upon bones for the infertions ofTab. ii, mufcles, as the Trochanters of the thigh bones, ^ ' '^' where it would weaken the bones too much to have procefTes raifed out of their fubilance. The fibres of bones, for ought that we can difcover from experiments or microfco- pical obfervations , appear to be conneded to each other by the fame means that the feveral parts of a fibre are conne61:ed, that is, by that llrong attradiqn which be- longs to particles of matter in contad: But this cohefion of fibre to fibre is not equal to that in the parts of a fibre, though very nearly. Indeed, if it was, a bone would not be aftru6ture of fibres, but one uniform mafs, like that of any pure metal, the cohefion of the parts of which are every way alike : Nor are the parts of bones difpofed into Lamella, Stratum fuper Stratum, as G — di, and others have painted j for though young bones may in fome places be fplit into Lamellse, yet they not only appear one folid uniform mafs to the naked eye, but even v/ith a microfcope^ till we come to their inner fpongy texture, which alfo appears uniform. The texture of the bones when firfl formed, is every where loofe and fpongy, but as they increafe, they become in many pla- ces very compaft and denfe, v/hich rsfults in lo IntroduBton to the Bones. great meafure from the preffure of the bel- lies of the mufcles, and other incumbent parts *, as appears from the imprefTions which are made on the furfaces of the bones, and the rough fpines that rife on the bones in the interftices of the mufcles, which are very re- markable in the bones of men who have been bred up in hard labour. In thofe parts of the fiat bones that receive but little preflure, the outer Lamina only become compa6t and denfe, and the middle part remains fpongy \ but where the preffure is great, they become one denfe body or table -, and this preffure is fo effedlual, that fome parts of the Scapula, and the middle of the Ilium, are ufually thinner in an adult body than in a child before it is born. The cylindrical or round bones being preffed moft in their middle, . become there Tab.v. D. very hard and ftrong, while their extremities grow fpongy, and dilate into large heads, which make ftronger joints, and give more room for the origins and infertions of the mufcles i and increafe the power of the mu- fcles, by removing their Axis farther fronj the center of motion of any joint they move. All the bones, except fo much of the teeth as are out of the fockets, and thofe parts of other bones, which are either cove- red with cartilage, or v/here mufcles or liga- ments arife or are inferted, are covered with a fine IntroduBton to the Bones. II -5* a fine membrane, which upon the fcull is cal- led Pericranium , elfewhere Periofteum ; one ufe of which is for the mufcles to flide ealily upon, and to hinder them from being lace- rated by the roughnefs and hardnefs of the bones. This membrane is faid to be exceed- ing fenfible of pain, which, I fuppofe, is ima- gined from the pain that a blow on the ihin gives : but it Ihould be confidered how much greater the contufion is in that cafe, from its lying upon a hard body -, for this is certain, chat when we cut this membrane, or feparate it from the bone, as we do, to prepare for the operation of the Trephine \ the patient never difcovers any extraordinary uneaiinefs, and that great pain which is fometimes felt at the fawing the bones or a bone in an ampu- tation, is when the teeth of the fav/ touch the great nerves that always lie near the bones, and not from the Periofteum ; for if it proceeded from that, this complaint would be more conftant, and at leafc as great at the firft fetting on of the faw, or at the lail ftroke, as at any other time. In a body that I dilTeded, who died of a fpotted Fever, I found in many of the bones extravafated blood ; and in feveral places, particularly on the Os Humeri, and Os Fe- moris, a large quantity of blood between the Periofteum and the bones. I imagine it may is be IX IntroduBion to the Bones, be from luch extravafations of blood that carious bones fometimes follow violent fevers, and the fmall-pox. I N children that have died of the rickets, I have always found the nodes on the bones very fpongy and bloody, and in one inftance feveral of the bones as limber as leather, and the Periofleum in many places ten times its natural thicknefs -, but the cartilages in all that I have differed, have had no apparent alte- ration in their texture , though they were fwelled to more than four times their natural bignefs, Tab.v.D. E V e ry cylindrical bone has a large middle cavity, which contains an oily marrow, and a great number of leiTer cells towards their extremities, which contain a bloody marrow; this bloody marrow is alfo found in all fpon- gy cells of bones. The ufe of the firft kind of marrow is to foften, and render lefs brittle the harder fibres of bones am.ong which it is featedj and the other marrow is to be of the fame ufe to the lefs compad fibres, for an oily marrow might have made them too foft \ and for this reafon, there is lefs of the oily m.arrow, and more of the bloody in young bones than in old ones. Every one of thefe cells is lined with a fine membrane, and the marrow in the larger cells is alfo contained in thin membranous veficles, in which mem- branes IntroduBton^ to the Bones, 1 3 branes I fuppofe thofe vefTels lie that fecrete the marrow ; if the bones had been formed of the fame quantity of matter without any ca- vities, they would if they v/ere ftreight be a- ble to fuilain the fame weight that they now can; But they being made hollow, their llrength fo as to refifl breaking tranfverfly is encreafed as much as their diameters are en- creafed, without encreafmg their weights, which mechanifm being yet more convenient for birds , the bones of their wings, and for the fame reafon their quills have very large cavities. But the bones in the legs of all a- nimals are more folid, being formed to fup- port weight; and mens bodies being fuppor- ted but by two limbs, the bones of their limbs, are therefore made more folid than thofe of quadrupeds. But in a fradlured bone, in which the fame kind of matter that olTified the bones at firft, is thrown out from the ends of the broken bone, there is made a mafs of callous matter, of equal folidity with any part of the bone , and of equal or greater diameter ; which will make the ftrength of the bone in that place greater than it was before : And if we confider, we fhall find this a very wife pro- vifion, for bones when broke, are feldom or never fet in fo good a diredlion as that in which they were firft formed, and therefore they would be more liabk to be broke in the I fame 14 IntroduSt'ton to the Bones. fame place again, and would be reunited with greater difficulty, and fometimes not at all, becaufe the Callus not being vafcular, would fcarce admit the oflific matter to flow through it to form a new Callus. The names of the articulations of the bones being varioufly ufed by authors, and being but of fmall confequence, I give the fhorteft account that I can of them. An ar- ticulation for manifeft motion, is called Diar- throfis ; for obfcure motion, Synchondrofis j and that kind which is without motion, Syn- arthrofis* D I ARTHROSIS, is divided into two kinds j viz. Enarthrofis and Ginglymus. Enarthro- fis is where a round head is received into a round cavity, which mechanicks call the ball andfocket; though none of the articulations in a humane body fully refemble that, unlefs the upper end of the thigh bone, with the Os Innominatum. Ginglymus is always defcri- bed by authors to be v/here a bone receives, and is received, which is right, where they are joined fomewhat like hinges, as the ob- lique procefTes of the Vertebrae of the loins,? where authors ufually take two joints to make a Ginglymus, that it may anfwer their defcrip- tions, though any one of thofe joints is a true Ginglymus. But in the other Vertebra, and in the articulation of the Ulna, with the Os Humeri, Of the Sutures. ly Humeri, and that of the Radius with the Ul- na, there being only the motion of hinges, without the form to give thefe joints this de- nomination ; we may for the fame reafon call every joint a Ginglymus, whofe property is only to bend and extend, as the knee, an- kle, &c. And what makes it more necefTary to bring thefe joints under this head, is, that they are reducible to no other. Synchondrosis, is by intervening car- tilages or ligaments, as between the bodies of the Vertebras j but the trueft Synchondro- fis is the joining of the ribs to the bone of the Sternum. Synarthrosis, is of two forts, viz. Su- tura and Gomphofis. The firil kind is the mu- tual indentation of one bone with another, as is eminently feen in the fcull, and the other the fadening of the teeth in their fockets, like a nail in wood. CHAP. II. Of the Sutures and Bones of the Head. THo s E Sutures which have proper names, are here defcribed; thofe which have not, derive their names from the bones they furround, and are known by them. S U T U R A 1 6 Of the Bones of the Head. ^Tab.iii. r. SuturaCoronali s,runs acrofs the fcull, and joins the parietal bones to the frontal. Tab.iii.2. Sutura Sagit talis, joins the parietal bones ; it begins at the Os Occipitis, and is continued to the Os Frontis ; in children down to the nofej the Os Frontis in them being two bones, and fometimes fo in adult Tab. V. bodies. Tab.iii.3. Sutura Lambdoidalis, joins the back part of the Olla Bregmatis, or parietal bones, to the upper part of the occipital : In this future are frequently obferved fmall bones. Tab. iii. ^.|2g^ ofla Triquetra. Tab.iii.4. Sutura Squamosa, is made by the wrapping of the upper part of the temporal and fphenoidal bones over the lower edges of the parietal bones. Tab.iii.v. Sutura Transversalis, runs acrofs the face, through the bottoms of the orbits of the eyes ; it joins the lower edge of the fron- tal bone to the Os Sphenoides, Maxills Su- perioris, OlTa Ungues, Palati, Plana, andju- galia, or Malarum. The fcull being thus divided into many bones, is neither fo fubje6l to frad:ures, nor to have fradcures fo far extended, as it would have been were it compofed of one bone only. This ftrud:ure is alfo convenient for the ofTification of the bones (as has been fliewn in the firft chapter) and for the birth, becaufe.* ^ Of the Bones of the Head. 1 7 becaufe thefe bones not being perfed: at that time, may be prefled together- and make the head lefs. Te n of the bones of the head corapofe the fcull to contain the brain. Thefe Ihall be firft defcribed. OssA Parietal I A or Bregmatis, are Tab.iii.7. twa large bones^ which compofe the fuperior- and lateral parts of the fculi ; on the infide they are remarkably imprinted by the arteries '^^^- "^"*' ofthe Dura Mater. ^^ Os Front IS, makes the upper and fore- Xab.iii. 5. part ofthe Cranium*, its lower parts compofe the upper parts of the orbits of the eyes. On its infide are imprelfed the external figure of the two hemifpheres of the brain. In thin fculls this bone has ufually a large thin fpine in the diddle ofthe infide, running from the Os Eth- -moides towards the crown of the head^ but in thick fculls it is frequently wanting, and in very thick ones ufually a Sinus in its place; theufe of this fpine is to ftrengthen thin fculls. Immediately above the Os Ethmoides in this bone, is afmallblind hole, through which runs a vein into the beginning ofthe longitudinal Sinus of the Dura Mater; between the eye- brows in this bone, are two or three large Si- nufes, and fometimes four or ^Yt^ which lead into the nofe \ and on the upper edge of each orbit, a fmall perforation, or a natch, through C which 1 8 Of the Bones of the Head. which nerves and an artery pafs fecure to the forehead : It has alfo a fmall hole in each orbit near the Os Planum , through which pafTes a branch of the fifth pair of nerves. The Sinufes and fpine in this bone make it very dangerous, if not impradlicable, to apply a trephine on the middle and lower part of the forehead. OsEthmoides or Cribriform e, is a fmall bone about two inches in circumfe- rence, feated in the arterior part of the bafis of the fcull, being almoft furrounded by the laft defcribed bone ; it is full of holes like a fieve, through which it is faid the olfadlory nerves pafs, which I could never difcover. In its middle arifes a large procefs named Crilla Tab. viii» Galli : And oppofite to this a thin one which ^3' in part divides the nofe. The greater part of the Lamina Spongiofse in the nofe, belong to this bone. Tab iii. OsSpHENOiDES, isofa very irregular 14. figure *, it is feated in the middle of the balls of the fcull, bounded by the Os Frontis, Eth- moides, Vomer Occipitis, Maxillae Superioris, OfTa Parietalia, Palati, Malarum, Temporum, andPetrofa, which are parts of the former Tab viii ^^^^s- -^^ ^^^ inlide next the brain is a cavity, 18. named Sella Turcica, which is bounded by four procelTes called Clinoides ; and oppofite to the Sella Turcica is a procefs which makes part of the Septum Narium. On the outfide of Of the Bones of the Head. 19 of the fcuU adjoining to the upper jaw, are two procefTes of this bone on each fide, named Pterygoides, from which arife one on each fide Tab.iv» near the palate, having no name ; over which ^' ^^^ are refleded the tendons of the Pterygoftaphy- lini Externi mufcles *, and nearer towards the Occiput, between thefe and the Styloid pro- cefTes of the OfTa Petrofa, arife two more fmall rugged procefTes ; and under the Sella Turcica in this bone, is a Sinus or two v/hich open into the nofe, and in fome fcuUs only" fuch a fpongy fubflance as is feen in the ends of fome of the bones. At the infide of the bafis of the two anterior clinoid procefTes are two round holes, which are the iirfl Foramina of the fcull •, through thefe the op tick nerves pafs \ almofl under thefe, towards the fides of the fcull, are two irregular flits, named Fora- mina Lacera, or the fecond Foramina of the fcull, through which pafs nerves and blood^ vefTels into the orbits of the eyes , and under" thefe towards the Occiput are two round holes ^ which are the third Foramina, through which pafs nerves to the face \ about half an inch nearer the Occiput, are two more of an oval figure, which are the fourth Foramina, through which pafs the largefl branches of the fifth J^^' ^^^ pair of nerves ; and a Ilraw's breadth farther two very fmall ones, called the fifth Foramir /la, through which thofe branches of the Ca- G % i'Otid 2 0 Of the Bonn's of the Head, Ta:3. IV. rotid arteries enter that are beflowed upon ^^"'* the Dura Mater. Between this laft defcribed bone and the OfTa Petrofa, are two large Tab. iv. rough holes, in which I have fe en large veins; *3- and from thefe holes through part of the Os Sphenoides, under the Pterygoid procefifes ^re fmall holes, through which pafs nerves and arteries to the back part of th€ nofe. Tab iii 0. O s s A T E M p o R u M, are fituated below the parietal bones, at the middle and lower parts of the fides of the fcuUj they have each at their back-parts, one large proceft, called Tab. iii. MamJiiillaris , or Mafloideus , and from the ^^' lower and middle parts of each a procefs which joins the OlTa Malarum, named Jugalis or T.b.^,iii. 2ygomaticus. OssaPetrosa, lie between the former bones and the occipital bones, or are truly portions of the former bones, being never found feparate in adult bodies. They have each on their outfide one long (lender procefs, cal- «,,... led Styliformis, and from the fide of this pro- 12. cefs a Foramen, which runs obhquely forwards ^ . into the fculh thefe are the fixth Foramina; B. 5*. * and one Foramen in the infide of the fcull lead- ing to the organs of hearing, which are the Tab. viii ^^^''^1'^^^ Foramina. The ridge on the upper 2 5' parts of each of thefe bones in the infide of the fcull, as alfo on each fide raifed by the Os Fron- tis and SphenpideSj help to keep the brain "I "' ■ Heady, Of the Bones of the Head. z i fteady, (See chapter Of the Dura Mater) and are admirable fupports to the thin and flat parts of the fcull, which elfe would be exceed- ing weak. (For what remains of this bone, fee chap. Of the organs of hearing.) Between the laft defcribed bones, and the following bone, are tv/o large holes, which are the eisihth Foramina. Through thefe holes ^^^' ^^• > 14. fafs the Par Vagum and Lateral Sinufes •, fome- times there are two on each fide, one for the nerve and one for the Sinus. To thefe we may add another very fmall one »on each fide, through which pafs the Portiones Durse of the auditory nerves-, and forhetimes there is another for an artery. Os OccipiTis, makes all the back-part Tab. iv. 'of the fcuII ■, it is bounded by the fphenoidal, ^* temporal, petrofal, and parietal bones •, it has two fmall Apophyfes, by which it is articulated Tab. viii. to the fpine ; near thofe Apophyfes are two ^" fmall Foramina, which are the ninth of the Tab. viii. fcull*, through thefe pafs the ninth pair ofi°* nerves •, and between thefe is the great, or tenth Foramen, through v/hich the Medulla Tab. iv. Oblongata defcends into the fpine, the cervi- ^' ^5* cal arteries enter, and the cervical veins and tenth pair of nerves pafs out. In the infide of this bone is a crucial fpine impreiTed by the longitudinal and lateral Sinufes , and on the aiitfide oppofite to the middle of this fpine, C 3 in zi Of the Bones of the Head. Tab.viii. in fome bodies, is an Apophyfis, and from that ^* down to the great Foramen, a fmall thin fpine. The fpines in this bone are of the fame ufe with thofe in the Os Frontis, &c. viz. to ftrengthen it, which they do here in a great- er degree than in any other bone of the fcull. The thinner parts of this bone are alfo defend- ed by the mufcles that cover them. This pro- vifion is very necefTary, becaufe we can leaft defend this part, and blows here are of worfc confequence than on any other part of the fcull, becaufe wounds in the Cerebellum, which is underneath, are mortal. There are in mofl fculls, a Foramen behind each Apo- phyfis of the occipital bone to the eighth Fo- ramen j through which pafs Sinufes, from the Jateral Sinufes, to the external cervical veins : By means of thefe communications,as in all other communications of the Sinufes, the blood palTes from thofe that happen to be furcharged by any poUure of the head, into thofe that from the fame pofture would elfehave been almoft emp- ty. Such fculls as want thefe Foramina, have two Sinufes for the fame purpofe within the fcull. The remaining bones of the headcompofe the face, orbits of the eyes and the jaws. Tab. iii. O s s A Nasi, are fmall oblong bones- which make the upper part of the nofe , they make that kind of arch which is fittefl to fuf- tain fuch injuries as the nofe is moll expof- ed Lo. OssA 16. Of the Bones of the Head. 2 3 OssaMalarum, thefe bones compofe the T^^- ^^i" cheeks, and the anterior, lower and outer parts ^" of the orbits of the eyes •, they have each a fhort procefs, which procefles join the ProcefTus Juga- les of the temporal bones, and form arches which by fome Authors, have been called OlTaJugalia. OssA Ungues, are fmall bones about Tab. iii. as large as thumb nails, feated immediately^^* below the Os Frontis towards the nofe in the orbits of the eyes, whofe anterior and inner parts they help to compofe; and between each of them and the upper jaw is a Foramen Tab. iii. as large as a goofe quill, imto which the Punc- ^9- ta Lacrymalialead, to carry off any fuperfluous moifture from the eyes into the nofe. OssA Plana, are thin fmooth bones Tab. iii, Icated immediately beyond the foregoing ^ * bones, in the orbits of the eyes, and are near thrice as big. They are indeed, but fmooth furfaces of the Ds SpongLofum, and not di- ilin6t bones. MaxillaSuperior, is always defcrib- '^^^- ^^^* ed fmgle, though it is manifellly divided by a future which is fcarce ever wholly oblitera- ted. It runs up with two proceffes to the Os Frontis between the OlTa Nafi and Ungues, and another, which joins to the cartilage of the Septum Nafi. Its upper and outward parts make the lower parts of the orbits of the eyes, its lower fide, all that part of the - C 4 face 21 24 Of the Bones of the Head. face under the cheeks, eyes, and nofe to the mouth, and two thirds of the roof of the Tab. iii. j^q^-i^^ ^ Yittl^ below the orbits of the eyes, in this bone, are two holes, and behind the Dentes Incifores one more , which divides into two, as it opens into the Nofe, one on each fide the Septum Nafi. Between the poilerior grinding-teeth and the orbits of the eyes are two great Sinufes, called Antra Maxillae Superioris : And in the lower edge of this jaw are the Alveoli, or fockets for the teeth. Part of the fides of thefe cavities, that lie next the nofe, are only membranes which make the cavicies like drums, perhaps to give a grave found to the voice when we let' part of it through the nofe j but brutes not needing fuch variety of founds, have thefe cavities filled with Lamella, which are cover- ed with membranes in which the olfa<^ory nerves terminate, for a more exquifite fenfe of fmelHng, than is neceffary for men. I have feen an impoflhumation from rotten teeth in one of thefe cavities, which has been cured by drawing fome of the laft grinding- teeth, and by making a perforation into it through their fockets. Mr. Cowper has admi- rably defcribed this cafe. The figns of it are rotten teeth {linking breath, and great pain about the part. The drawing one or two of the lafl grinding-teeth, generally, if not al- ways. Of the Bones of the Head. i y — ways, in this cafe, opens a paffage into the Antrum ; but if not, or if the paffage is not large enough, it may be made or enlarged with a carpenter's nail-piercer or gimblet^ which is as good aii inftrument as can be for the purpofe. O s s A P A L AT I, are two fhiall bones that make the back part of the roof of the mouth, and a fmall part of the bottom of each orbit, unlefs thefe portions may be accounted di- ftin6l bones. Between the Offa Palati and Os Maxillare near the pterygoid proceffes of the fphenoidal bone , are two fmall Forami- na, through which arteries and nerves pafs to the palate. Os Vomer, is feated between the bones '^^^' v'"' of the palate, and the fphenoidal bone. It is" alfo joined to the procefs ofthe Ethmoides, and part ofthe lower jaw. Its fore-part is fpongy, and ^ is continued to the middle cartilage ofthe nofc' This bone and cartilage are the Septum Nali. Os Spongiosum, is ufually treated as a diftind bone, though it is only the fpongy La- minse in the nofe, of the Os Ethmoides and Offa Plana, but chiefly ofthe Os Ethmoides, to which it always adheres. In confidering thefe Lamellse as a diftinA bone, we follow the ancients, who did not diflinguilh the bori-es^ of the fcull only, as they are divided by * Sutui'es, but according to the differences of their i6 Of the Bones of the Head, their texture, figure, fituation, or ufe. Thus they called thefe parts, Os Spojagiofum j a procefs of the temporal bone, joined to the Os Malas, Os Jugale; the temporal bone, which is one with the Petrofum in adults, Os Temporis, becaufe it is feated under the tem- ples; and the other part, Os Petrofum, from itshardnefs or ruggednefs; and the upper jaw one bone, though it is always two. Tab. iii. Maxilla Inferior, is articulated with ^^- loofe intervening cartilages to the temporal Tab. iii. bones, by two procefles, named Condyloides. 24« Near thefe arife two more, very acute, called Tab. iii. Coronales, and at the infide of the chinafmall 13- rough ProcefTus Innominatus. In the infide of this bone under each ProcefTus Coronalis, is a large Foramen which runs under the teeth Tab iii. ^hi*ough this bone, and pafles out at the chin. 25. In this Foramen or chanel, the vefiels pafs that belong to the teeth; and in the upper edge of this jaw are the Alveoli, or fockets for the teeth. D E N T E s, the teeth feldom exceed fixteen in each jaw ; the four firfl in each are called Incifores, the two next Canini, and all the refb Molares •, the four lafl of thefe are named Dentes Sapientise, becaufe they do not appear till men arrive at years of difcretion. The Incifores and Canini have only one fingle root, but the Molares more \ the eight firfl, two 5 and Tab. iii. Of the Bones of the Irimk. x/ and the reft, fome three, fome tour; efpecial- ly in the upper jaw, becaufe the upper jaw being more fpongy than the other, the teedi need more fangs to ^yi them. Each of thefe fangs, or roots, has a Foramen, through which pafs an artery, vein, and nerve •, which are ex- panded in a fine membrane lining a cavity in each root of a tooth. This membrane is the feat of the tooth-ach. The teeth of children caft off while they are growing \ but the fucceeding teelh arife in new fockets, and larger than the former ; for the jaws increafmg fafter than the teeth , muft otherwife of neceffity have left chafms between'them, fuch as there are in the mouths of brutes *, but where teeth are drawn in adult bodies, the fockets clofe and new teeth very rarely arife. CHAP. III. Of the Bones of the Trunk. TH E bones of the trunk are thofe which conipofe the fpine or chain of bbnes from the head down to the rump, the ribs and Sternum. The fpine, is compofed of twenty four Xab.i.ii*. Vertebrx, (each of v/hich in a young child is three 2 8 Of the Bones of the Trunk _ three bones) befides thofe of the Os Sacrum and Coccygis •, feven belong to the neck, the Tab.iv.G. ^rft of which is called Atlas, the fecond Den- tata, from a procefs in that bone bearing the fame name ; twelve to the back, five to the Tab. iv. Loins. The Os Sacrum is fometimes five^ ^* fometimes fix bones , and the Os Coccygis four. If this chain had been compofed of fewer bones, they mull have either not been capable of bending fo much as they do, or have bent at lefs obtufe angles, which would have prefs'd the fpinal marrow. Tab iv ^ ^ ^^^ thefe Vertebra, except the firft, is a H.LK. middle anterior fpongy body, by which they '• are firmly articulated with a very llrong in* tervening ligament •, and from the middle of the hind part of each, except the firft, ftands a . procefs named Spinalis, and from every one a procefs on each fide, called Tranfverfalis, and \ ' two fuperior, and two inferior fhort ones; by which the back parts of the Vertebrae are ar- ticulated, named Obliqui, Superiores, and Inferior es. The fore part of the feven Vertebras of the neck, and two upper of the back, are flat for- wards, to make room for the Afpera Arteria and Gula : The third and fourth of the back very acute, to give way to the divifion of the veflels of the lungs and heart, and bent to the right ^hXq for the fituation of the heart, which Of the Bones of the frunL 1 9 which makes that fide of the breaft fomewhat more convex than the other, and therefore I think ftronger 5 which is an advantage to the right arm, becaufe its motions depend upon the fupport it receives from the breaft. Hence, I think, it feems that the almoft univerfal preference of that arm is not an arbi- trary thing, but founded upon obfervation, that it is capable of more perfed: actions than the other. The fpinal procefies of the fecond, third, fourth and fifth Vertebrae of the neck are fork- ed, the two laft of the neck long and horizon- tal, the three or four upper ones of the back like them, only a little declining, the middle ones of the back run obliquely downwards, and the procefTes of the remaining Vertebrse become fucceflively thicker, ftronger, and iefs declining 5 thofe of the Loins being hori- zontal, like the laft of the neck. The muf- cles that are inferted into the fpinal procefTes of the Vertebrae of the neck and loins, will a6t with more ftrehgth than thofe of the back, becaufe their procefTes being perpendicular to the fpine, they are longer leavers ; befides, thofe of the back touch one another, and pre- vent much motion, becaufe it would interrupt refpiration ; and much motion being necefTary in the neck and loins, their procefTes are made fit for it. The 3 o Of the Bones of the Trunk. The tranfverfe procefles of the Vertebrae of the neck are perforated, for the admifTion of the cervical blood-veffels, and bowed down- wards, and hollowed, for the pafTageof the cer- vical nerves. The eight or nine upper ones of the back, receive the upper ribs*, and the reft, with thofe of the loins, ferve only for origins and infertions of mufcles. The fhape of the fpine is like an Italick/ bending inwards at the loins, and outwards at the fhoulders ; therefore when women that are either very young or very weakly, breed, the child by a continual prefTure againft the loins, makes them ftreighter, which neceflarily makes the Ihoulders or back fo much more convex, and the prefTure upon the abdominal mufcles at the fame time bringing the ribs downwards, they grow round-fhoulderedand flat-breafted. Tab ii Os Sacrum has two upper oblique pro- 13. cefTes, fome fmallfpinal procefies, and two Fo- ramina in each interftice of the bones it is com- pofed of, both before and behind. Os CoccYGis has none of thefe parts. Through every bone of the fpine, the Os i^. ' ' Coccygis excepted, is a large Foramen, which together make a chanel through the fpine, in which is contained the Medulla Spinalis ; and in each fpace between theVertebrse are two large holes for the nerves to pafs out* Ti$ Of the Bones of the Trunk. 3 1 'Tis worth confidering, the provifion that is made to prevent luxations in this chain of bones, fuch luxations being worfe than any- other becaufe of the fpinal marrow which is contain'd within thefe bones. The bodies of the Vertebrae are all in the fame manner con- neded by flrong intervening ligaments or cartilages. In the neck the oblique procefTes of the received bone are wrapped over thofe of the receiving bone, which forbids their luxating forwards. The tranfverfe procefies with a fmall Apophyfis of the body of the fame bone, in like manner, fecures them from flipping backwards, and an Apophyfis on each fide of the body of the receiving bone, hin- ders them from flipping to either fide. The Vertebras of the back are hindered from dif- locating forwards by the fame provifion with thofe of the neckj and from luxating back- wards, by the ribs which are faftened to the tranfverfe procefTes of the inferior Vertebr^^ and againft the back-part of the body of the next fuperior; they alfo hinder them from diflocating to either fide -, but the ribs at the two or three laft Vertebra of the back are not fixed to the tranfverfe procefi^es, and there- fore it is that luxations are moft frequently feen in this part -, but the Vertebra of the loins are received into deep cavities, and are. tyed with much ftronger ligaments for their fecurity. Of the Bones of the Trunk. fecurity. Each joint of the Vertebrae, ex- cept the two uppermoft, has two centers of motion, one upon the bodies of the Vertebras, when the body is bowed forwards ; and the other at the articulations of the oblique pro- cefles, when the body is bowed backwards v from which ftru6hire the extenfors will have about twice the leaver to ad: with, and confe- quently twice the power to raife the trunk in- to an eredb pollure, that they have to carry it beyond that poilure ; for then the oblique pro- celTes begin to be the centre of motion, and give the fame advantage to mofl c^ the bend- ers. Without this contrivance it would have been more difficult, if poffible, to have kept the body ereft for any length of time, or to have recovered an ere<5l pofture with confiderable ftrengthafter a bend of the body. JTab. i. ii. The ribs are twelve in number on each fide ; the feven uppermoft are called true ribs, becaufe their cartilages reach the Sternum ; and the five loweft are called baftard-ribs. They are articulated to the bodies of the twelve Verte- bra of the back, and all except the tv/o or three laft are articulated to their tranfverfe procefifes, and the under fide of the middle ribs are hollowed for the pafiage of the inter- ^oflal vefiels. They defend the parts contain- ed in the breaft, and when they are drawn upwards, the cavity of the breaft is enlarged for Of the Bones of th^'l'runk^ ^ j for infpiration, and fo the contrary. In two chil- dren which I have dilTeded, I found the ribs broke inwards, and on the outfide a plain print of a thumb and four fingers, which had been made by their nurfes hoifling them up on one hand, taking hold of their breafts, which being very often repeated, had broke the ribs inwards like a green flick, without feparating the broken ends of them-, and I have very frequently i^tVi the Ihape of childrens breafts quite fpoiled by fuch tricks, which has occafioned weaknefs of body, crookednefs, and other Difeafes. S T E R N u M, or breaft-bone, is generally made Tab. i. 2. lip of three fpongy bones, fometimes more, to this the true ribs are articulated by their carti- lages. See chapter of the cartilages. Os Hyoides ( I chufe to mention it in Tab,iv.C, this place, becaufe I know none more proper among the bones ) is a fmall bone at the root of the tongue \ it ferves only for mufcles to arife from, and be inferted into. It is made of three bones, the middle one is called Balis, '♦ the other Cornua. I H AVE feldom found fewer than four and twenty Vertebras in the fpine, befides the Os Sacrum, but often more \ fometimes thirteen of the back, with as many ribs of a fide j and fometimes fix in the loyns : And in fome bodies two ribs from the firft Vertebra of the loyns ; but then it has wanted tranfverfe procefTes. D A WOMAN 3 4 ^^f ^^^ Bones of the upptt i . : rnps. A WOMAN in the hofpital with the venereal difeafe, having feveral bones carious, among the reft two of the Vertebra of the Neck had their fpongy bodies corroded, which feparating from their other parts while fhe was in a falivation, her head could no longer be fuftained, but bowing forward, the fpinal marrow was comprefled and fhe died foon after. CHAP. IV. Of the Bones of the upper Limbs. Tab i, 3. /^^Lavicula, is of the figure of the ii. 3. \^ italick f^ one end is articulated to the Sternum, and the other to the ProcefTus Acro- mion of the Scapula ; it ferves to fix the Sca- pula, and to determine its motions. This bone is oflified as early as any bone in the body, and is the fooneft united when broken. Tab i" 4 Scapula, its parts are the' Acetabulurri, which is a fhallow cavity to receive the Os Humeri : A large fpine from whofe fore-part _, ftands a procefs called Acromion, and another procefs from the fore-part of the upper edge of the Scapula named Coracoides ; its upper edge is named Cofta Superior, and its lower \ one Cofta Inferior, and the pofterior edge its Bafis. I have feen a Scapula of a man which Dr. Douglafs dillefted, in which the infide of ^ the Of the Bones of the upper Ltmhs, 3 j the Acetabulum Scapula was broke all to pieces, and the Os Humeri difplaced 1 which fracture, I believe, could not by any means be certainly known while the man was living, or if it could have been known, could not have been cured; yet I doubt not but the furgeon, whoever he was, did not efcape cenfure for nor making a cure. Wh,e NEVER the Procefius Acromion is broke, the arm can never after be raifed to advantage ; for no care of the moft fkilful furgeon can reduce fuch a fracture; for the Deltoid mufcle will draw the ends of the brokfen procefs afunder, and will want a mid- dle fixed place to a6t from. Os Humeri, this bone has at its upper TaK i, 5. €nd a round head for its articulation , and "* * near that an Apophyfis, which is divided by a SulcuSj in which runs a tendon of the Biceps Flexor Cubiti. At its lower end are two Apo- phyfes, named the outer and inner. Between thefe Apophyfes on the fore-part of the bone, is a fmall Sinus, which receives a protuberance of the Ulna, and behind a large and deep one, which receives the Olecranon of the Ulna. This bone being more liable to be broke by a blow than any other way, and it being uncer- tain where that Ihall fall, it is made of almoft equal ftrength through the whole length of it ; and its lower end having a very fmall joint, for D. %.; the 5 6 Of the Bones of the upper Ltmhs, the fake of a quick motion, the Sinufes are formed there, to receive the procefies of the^ Ulna, to prevent diflocations. Tab. i. 7 . Ul N A, at its articulation to the former bone ^i- ^- has two procefies, one large and thick, named Tab. ii. 9. Olecranon, and one fmall one, named Procefius Anterior, and at the lower end of this bone is a fmall procefs, named Styloides. When about two inches orlefs of this bone is broke off at the lower end, it is fcarce pof- fible to raife it into its natural fituation till the arm be turned prone i becaufe in a fupine pofture the tendon of the TenforUlnaris rides over it, and prefles it down. Tab id Radius is received at the upper end by ii. 7. the Os Humeri and Ulna; at its lower end it receives the Ulna and Carpus. By its turning upon the Ulna, are performed the prone and fupine motions of the cubit. About an inch below its upper end is an extuberance for the infertion of the Biceps mufcle. _ Carpus the wriil, is compofed of eight M. 1,2*3, bones of irregular figure-, they are diilinguifh- 4»5i<^»7» ed into four of the firft order, and four of the fecond. The two firft of the firft order are articulated with the Radius, the lirft of the fe- cond order is articulated to the thumb, and the remaining three to the metacarpal bones. The infide of thefe bones leave a femilunar cavity for the tendons of the mufcles which bend Of the Bones of the lower Limbs. 37 " ■ ■ - , I — I — ' bend the thumb and fingers to pafs through. What other reafons there may be for this par- ticular compofition of bones , I know not ; but this is plain, that by being moveable, one among another, they gradually give way, and leflen the fhock which any force againft the hand would give, as the box of fprings does the jolting of a coach, and thereby make the force lefs in each moment of time upon every bone of the arm, which greatly preferves them from breaking ; and the Scapula being fixed by mufcles, contributes very much to this purpofe. This is an advantage that cannot be exadlly computed; but it is certainly very great. Metacarpus, is compofed of four bones. Tab.iv. Poll EX, thethumb is made of three bones. M.p. DiGiTi, the fingers are each compofed of j^^ '^]^' three bones. For the figure ofthefe, fee the Table, which will give a better idea of them fab. iv, than. a verbal defcription. M. n. CHAP. V. Of the Bones of the lower Ltmhs. S Innominatum, is, before puberty, compofed of three bones; the upper- jij,^' moil is named Ilium, the lower and anterior Os Pubis, the lower and pollerior Os Ifchii. D 3 The o 38 Of the Bones of the lower Limbs. U»J--i"- "'■'■■'■ ' ■ '■ HI '' II ri r.-i 1 » The upper edge of the Ilium is called its fpine, the anterior part of the fpine its Apex, and lower than this is the Procelfus Innominatus. The Ifchium has two proceffes, the one called Acutus, the other Obtufus. In the center of thefe bones is the Acetabulum, or focket, to receive the thigh-bone; in the bottom of which focket is another cavity, in which lies the lubricating gland of this joynt ; and be- Tab.Lip.^^ggj^ the Os Ifchium, and Os Pubis, is a large Foramen. Jab.i. 12. O s F E M o R I s, at its upper end has a round head which is received into the Acetabulum of the Os Innominatum. A fmall diftance Tab,!. i3.fj.Qj-j^ this are two proceffes, named Trochan- Tab ii ter Major, and Trochanter Minor. The fpace I7» between the greater procefs and the head of this bone is called its neck, and from the Iti^- fer Trochanter down the back-part of this bone till within four or five inches of the lower end, is a ridge, called Linea Afpera. At the lower end of this bone are two Apophyfes, one exte- rior, and one interior. The chief ufe of the Linea Afpera is, to ftfengthen the thigh-bone ; it is therefore fo ordered, that it is always la%e, proportionably to the bend of the thigh-bone, and largeft in that part of every thio;h-bone c , .; that IS molt bent. • ^ —' Tab. vi. I N two bodies which I have dilTedled, I have ?? M • found this bone broke at its neck, and by that means Of the Bones of the lower Limbs, 3 9 means the limb iliortened, and the cafe mifba- ken for a luxation of the hip ; and if we con- fider the depth of this articulation, and the wonderful ftrength both of the mufcles and ligaments, we cannot but fufpe6t that this bone is much oftener fo broke, than out. This is certain, that if by an external accident the thigh is made Ihorter, and yet is ufeful, that muft needs be from a fradure, and not a dif- location; for it cannot be, that the head of the thigh-bone Ihould form it felf a/ocket a- mong the mufcles, to bear the whole weight of the body : Or fuppofmg this could happen, though it is contrary to what we know in other like cafes, yet even then we muft have new mufcles made, or thefe we have altered s for their directions with the thigh-bone being changed, their ufes would too, and almoft all pull to the fide contrary to which the bone is diflocated. It often happens, that from a flux of hu- mours upon the hip, this joint appears dif- located-, for when it is attended with pain, the mufcles contra6ling alter the pofture of the limb, and make it appear fliorter, as the limb which is lifted from the ground is when we ftand on one leg : But if the fluxion is with- out pain, the mufcles relax, and the limb falls into the fame figure, which that lim.b is in, which we ftand on in that pofture, and appears D 4 longer^ 40 Of the Bones of the lower Ltmhs, longer; which makes the common way of comparing of the limbs a very uncertain, if not impofTible way to difcover the cafe •, there- fore to know certainly, apply a ftraight rule from the Apex of the fpine of one hip to that of the other, then from the middle of that rule draw a perpendicular line between the legs; then meafure the limbs at that line In the fame plane, and if their lengths are equal, they are moil certainly right. Tsb.i. 14. Fatell a. the knee-pan is feated upon the joint of the knee ; its ufe is for the extenfors of the Tibia to be inferted into, left pafiing over that joynt, they might be too much ex- pofed to external injuries ; it alfb gives an ad- vantage to the mufcles, by removing their Axis farther from the center of motion of the knee. Tab i. i8» Tibia, the fhin-bone is in its middle almoft \\. 18. triangular, which it feems to owe to the pref- fure of the mufcles, for it is cylindrical in a Foetus. In its upper end are two fhallow fock- ets, between which is a procefs for the crofs ligament of the knee to arife from ; a little be- low its head is another proceis, to which the ligament of the Patella is iixed, and at its low- er end another, which makes the inner ankle. A B OY of {^\tr\ years old was brought to me with both the Epiphyfes at the upper ends of the Tibi-c-E, fo far feparated from the Tibise, that Of the Bones of the lo wer Ltmbs. 4 1 that not more than half each Tibia was joined to half the Epiphyfis, which made the legs ■ wholly ufelefs. This had been occafioned by - the nurfe holding him out to ftool by the heels and back, when very young, which is among them too common a pradice. I difieded the leg of a man that had broke the Tibia through the flefh, by a fall from the top of a houfe ; no exteniion that was made moved this com- pound fradure at all, which I afterwards found to be occafioned by a fimple tranfverfe fracture above, which always gave way to the exten- fion ; that bit of bone whofe end came through the fl^in, being difcontinued from the parts by which the extenfion was made. In the foot of the fame leg, four of the bones of the Tar- fus were cracked, two more of them, viz. the Os Calcis and Naviculare, had large pieces fe- parated, which were broke into a mafh ; and all this v^ithout any difiocation among thefe bones, or any the leail external wound or bruife. FiBULii, is a long fmall bone, its upper ^^^ - , end is articulated to the outfide of the Tibia, ii. 19. an inch below its joynt, and the lov/er end makes the outer ankle, and part of that joynt ; its chief ufe is for origins of mufcles \ for it has no fhare in fupporting the body. Aftrain ot the woril kind happens often to this joynt from the mighty force of the Peronei mufcles, when 42 Of the Bones of the lower Limbs. when we endeavour to prevent a fall ^ for they being turned over the end of the Fibula , as on a pulley, part of their force lies againft this bone, and ftreins the ligaments that hold it, and fometimes the bone it felf is broke by them; which wants no care to fet, and can feldom be difcovered till the fwelling is fallen. Tab.iv L ^^ R s u s, is made up of feven bones, which 1,2,3,4, are called Aftragalus, Os Calcis, Naviculare, ^'^'7- Cuboides, Cuneiforme, Majus, Medium, and Minimum. The bones of the Tarfus have the fame kind of elaftick flrudure with thofe of the Carpus, and for the fame ends, but in a much greater degree ; becaufe here the whole body is fuftained. This fort of contrivance, and the ufe of it, are both very evident in the laft joynts or pafterns of the legs of horfes ; for horfes that have long pafterns, and much ela- ftick motion in them , muft neceffarily trot high, and yet they always trot eafie •, but a horfe with ftiort pafterns, that trots high, al- ways trots hard. A N old man that had the under part of the Os Calcis laid bare as large as a half-crown, by a mortification, being brought to the hofpital about two years after the bor^e was firft bare, and all endeavours to fcale it having proved ineffeftual, I pared it v/ith a chifel till the bone bled, and it covered with granules of fleih, in Of the Bones of the lower Ltmhs. 4 3 in about three days , and afterwards healed very eafily. M E-T ATA R s u s, is compofed of four bones. J^^* J^* Pol LEX Pedis, is compofed of three xab.' iv, bones. L. 9. D I G I T I Pedis, each is compofed of three Tab. iV. bones, but the two laft of the little toe often ^- ^^' grow into one. For the figure and fituation of thefe bones, fee the table. OssaSesamoidea, are faid to be found to the number of forty-eight : But we com- monly find no more in the feet than two un- der the ball of each great toe; and in the /p^ij^j^. p^ hands fometimes two very fmall ones at the middle joynt of each thumb ; and fometimes ^^^ jy g^ one at the lower end of each thigh-bone at the beginning of the Pkntaris mufcle. Their ufe Tab.iv.F. is the fame v/ith the Patella I find alfo in feme bodies the little cartilages dt the receiving ends of the bones of the fingers oflified-5 which furely thofe authors reckon a- piong the Selamoid bones , who fay they are fpund to the number of forty- eight. CHAP. 44 Of the Cartilages. CHAP. VI. Of the Cartilages. EVERY part of a bone which is articu- lated to another bone for a (liding mo- tion, is covered or lined with a cartilage, as far as it moves upon, or is moved upon by another bone in any a6lion -, for cartilage be- ing fmoother and fofter than bone, it renders the motions more eafy than they would have been, and prevents the bones wearing each other in their adions. Thefe cartilages in the largeft joynts, are as thick as a fhilling, and in the fmalleft, as thin as paper. In the forepart of each articulation of the. lower jaw, there is aloofe cartilage upon which the condyloid procefs moves on one fide, while the jaw is moved to the other; and the two procefles being thus raifed at once, the jaw is thruil forward. I N the joint of the knee are two loofe, al- moil annular cartilages, which being thick at their outer edges, and thin at their inner ones, they make the great eft parts of the twofockets in this joynt. The ufe of thefe cartilages is to make variable fockets to fuit the different parts of the lower end of the Os Femoris, for none but a round head and a round cavity can fuit in motion, unlefs the fhape of one or the other Of the Cartilages. 45- other alters ; and it is plainly neceffary, that this lower end of the Os Femoris, fhould be fiattifh, and projedled backward, to give advan- tage to the mufcles that extend the Tibia, by fetting the center of motion backward j which mechanifm, though it equally leffens the power ofthofe mufcles v/hich bend this joint, is yet of great fervice, becaufe the extending mufcles move this joynt under the weight of the whole body, but the flexors only raife the legs ; and as no head or focket moves fo eafily as round ones, here feems to be fome proviHon made againll the inconvenience of a fiattifh head and cavity, by having the fricflion made upon two furfaces, the Os Femoris upon the ioofe cartilages, and the Ioofe cartilages upon the Tibia. This con- trivance is always found necefTary by mecha- nicks, where the fri6tion of the joynts of any of their machines is great, as between the parts of hook-hinges of heavy gates, and between the male and female fcrews of large vices, where they always place a Ioofe ring. Th ere are other cartilages which ferve to give fhape to parts. Of this fort are the ci- liary cartilages at the edges of the eye-lids, the cartilages of the outer ears, and thofe v/hich compofe the lower part of the nofe, which have this particular advantage in thefe places, that they fupport and fhape the parts as well as bones do, and without being liable to be broke. ^ The /^6 Of the Cartilages. 3rab.i.zo. The ribs have cartilages of a confiderable length, which articulate the feven uppermoft, and fometimes eight on each fide to the Ster- num; which cartilages being very pliable, fuffer the ribs to move eafily in refpiration, and the body to twill or bend to either fide with- out difficulty. But the cartilages of the lower ribs do not reach the Sternum. And at the bottom of the Os Pe6t:oris or Sternum, is a car- tilage which is named from its commonefl fi- Tab.i.ii.g^re> Enfiformjs. T H E R E are other cartilages which compofe the Larynx and Afpera Arteria. The Larynx is formed of five : The foremoft is like a Sad^ die, but is named Thyroides j behind this are two called Arytsnoides ; they compofe the Rimula of the Larynx. Over thefe is the Epi- glottis to cover the Rimula vv^hile the aliment pafTes to the Pharynx; and under them one like a feal ring, named Cricoides. The car- tilages which compofe the Afpera Arteria, or remaining part of the wind-pipe, are not quite annular, but connedled by membranes at their back-part, to give way to the aliment defcend- ing through the Pharynx. There are other parts that authors call cartilages, which I rather chufe to rank with the ligaments: And therefore will defcribe them in that chapter, as thofe between the bodies of the Vertebr:^, &c, I HAVE Ofth he Ltgaments. 47 ■^^ I H AV E feveral times found fupernumerary cartilages from the Sternum, running between the ribs, and frequently the Cartilago Enfifor- mis double. I do not remember that I have ever feen a cartilage fcale like a bone, or flough likefofter parts, though I have often feen them eat through by matter that has been colledled in a joynt, which has fometimes occafioned the bones to grow together. Tab.iv.E^' ™ "' «_ __ CHAP, VII. Of the Ligaments. EVery bone that is articulated to another for motion, is ty'd to that it moves upon, by a ligament, whofe thicknefs and llrength always bears a proportion to the quantity of motion in the joint, and the force with which it is liable to be moved ; and the length of the ligament is no more than fufficient to allow a proper quantity of motion. The bones of the limbs that move to all fides, have ligaments like purfes, which arife from or near the edges of the fockets of the receiving bones, and are inferted all round the received bones, a little below their heads. The beginnings of thefe hgaments, from tdges of the fockets of the Scapula and Os In- nominatum 48 Of the Ligaments, nominatum are very hard, almoll cartilaginous, which ferves in the Scapula to make a larger focket, and fuch a one as will alter its figure as the bone moves, for the reafon I have mentioned in the loofe cartilages of the knee ; for the head of the Os Humeri, not ' being an exad: portion of a fphere, requires fuch afock- et, and the hard part of this ligament of the focket of the Os Innominatum makes the fock- et deeper than the femidiameter of the focket, without any hindrance to motion, becaufe it will give way to the neck of the Os Femoris, when it prefTes againft it. The ligaments of thofe articulations which admit only of flexion, and extenfion, differ " from the former in this only, that they are much Ihorter and ilronger at the fides of the joynts, and thinner backward and forward. At the upper part of the articulation of the Os Femoris and Os Innominatum, is a ftrong ligament of great confequence; it contributing very much to preferve that joint from being luxated by the weight of the body. And from the lower edge of the Acetabulum of the Os Innominatum, runs a ligament to the middle of the head of the Os Femoris, about two inches long (which the morion in this joynt requires) called Teres, or Rotundum, whofe ufe is to prevent the Os Femoris from being luxated upwards, but downv/ards it will let it go far out Of the Ligaments. 49 out of the focket j which fully fhews, that in men it is particularly contrived to prevent the thigh-bone from being dillocated upwards ; but in brutes the head of the Os Femoris being ob- long, and the cavity fuitable, there can be on- ly a rotatory motion which in the effedt will be very little more than that kind of motion which is called bending and extending y and this ne- ver removing the end of the head of the bone far in the focket, a Ihort ligament is enough for it, and will better keep the bone in its place; and therefore it is that theirs is fo fliort. This ligament in men may alfo ferve to prefs the gland in the bottom of the Ace- tabulum or focket. Towards the great Foramen, of the OfTa Innominata, the Acetabulum has a deep notch, from one fide of which to the other, runs a ligament, which I have feen olTifyed. Such a ligament there is alfo running from one pro- cefs of the Scapula to the other, which hinders the Os Humeri from diflocating upward. In the middle and back-part of the joint of the knee are two very ftrong ligaments which arife from a procefs at the end of the Tibia* They crofs each other in fuch a manner, as is beft to fecure the joint from being difplaced any way ; they alfo hinder the extenfors of the Tibia from pulling that bone too far for- wards* JO Of the Ligaments. All the bones of the Vertebrae, and eyery joint that is without motion, and not joined by a future, as the OiTa Innominata with each other, and the Os Sacrum with the OlTa Inno- minata, are all joined by intervening ligaments^ commonly called cartilages The ProcefTus Dentatus of the fecond Ver- tebra, is tied to the fcull by a ligament, and kept clofe to the forepart of the firft Verte- bra by another in that Vertebra, that it may not bruife the fpinal marrow; and when ei- ther this ligament or procefs is broke, it makes that fort of broken neck which is attended with fudden death. The bones of the Carpus and Tarfus are tyed together by ligaments running promifcu- oufly upon their furfaces from one to another j which at the under fide of the Tarfus are vaft- ly ftrong, becaufe they fupport the whole, bo- .dy. There is alfo to the Carpus, a ftrong li- gament which runs from the fifth bone to the eighth, and the procefs of the fourth bone : The proper ufe of this is, to bind down the tendons of the mufcles that bend the fingers. The OsHyoides to the ProcefTus Stylifor- mis of the Os Petrofum, the Patella to the Tibia, and the fefamoid bones in their places, are all tyed by ligaments. From the edge of the Ilium t^) that of the Os Pubis, runs a ligament which is contiguous 3 to. ■itWiiOTT ■■^ Tirir II Of the Ligaments. ji to, and appears to be a part of, the tendons of the oblique mufcles of the Abdomen 5 its ufe * is to cover the iliack veflels as they defcend to the thigh: Under this ligamerit, together with the vefTels, I have often met with a rupture of matter, and, I think, fometimes the gut, (however I dare affirm that to be a poflible cafe) frorti the Abdomen into the anterior part of the thigh^ immediately below the groi^« Such cafes are well worth the obfervation of furgeons ; becaufe opening fuch tumours may be of very bad confequence* The tendons of all the mufcles that are not involved in fat, are either tyed down to the bones they pafs over, by ligaments which contain a lubricating Mucus, or have fome- times communications with the joint they move : As has been curioufly obferved by Dr. Douglafs, particularly in the joint of the hip. The ufe of thefe ligaments is to confine them to their proper diredtions, and contain the Mucus that lubricates their furfaces, to make their motions more eafy. From the Tibia to the Fibula, and from the Ulna to the Radius , are tranfverfe liga- ments which help to keep thefe bones together, and give origins to a great /many mufcles. There is another of this fort in the great Fora- men of the Ofi Innominatum-, and one between the Os Sacrum andprocefles gfthe OfTa Ifchia; E 2, and ji Of the Lubricating Glands and fome more in the body, too fmall to have a particular account given of them in this place. Authors agree, that the ligaments afe infenfible \ and give for their reafon, that they would elfe be injured by ordinary motions. ' But they are much better contrived, feeing none of them, except thofe which lie between the bones, are fubjed to attrition; and thofe they have called cartilages. I do not think that thefe laft are ferifible : but the other I have had frequent experience are capable of very acute pains, there being not any thing our patients more grievoufly complain of, than coUedtions of matter within thefe parts, or fharp medicines applied to them when laid bare. / CHAP. viir. Of the lubricating glands of the joints. EVery joint where the bones are faced with a cartilage for a Hiding motion, is furnifhed with fmall glands, which feparate a mucilaginous matter for the lubricating of the ends of the bones, that they may move eafily upon one another; and that there may be no" j 1= wafte of the Joints, j2 wafte of this necelTary fluid, it is contained in the invefting ligaments ; which for this very reafon are no where divided, except to com- municate with the ligaments of tendons. These glands are generally feated near the infertions of the ligaments, that they may be comprefTed by them when the joints are in motion; which is a proper time to have their fluid prefled out. There is one large gland of this fort, feated in a Sinus at the bottom of the Aceta- bulum of the Os Innominatum, which is com- prefled by the Ligamentum Teres. When from violent bruifes, or any other caufe, thefe glands are ulcerated, they throw off' a corroflve matter, which erodes the carti- lages of the bones, 'till it inflnuates it felf into their fpongy heads, and renders their whole fubfliance carious. "When this difeafe happens to the hip, in time it makes its way through the liganient, and then it gets under the Glu- teus Maximus to the outflde of the thigh un- der the flat tendon of the Fafcialis mufcle, and fometimes to the forepart of the thigh, where the great blood-veflels run. In this cafe, which is very rare, I apprehend that the furrounding ligament is perforated before, as was mentioned in the lafl; chapter. Thefe cafes are generally, if not always, incurable. E J A Cafe 54 Of the Lubricating Glands ^ ^c, A Cafe of a fraBur'dfcull^ tn a Gtrl nine years of age. VideTah. IX. TFIIS girl being brought into the hofpital the twenty feventh of May, feven days after the fcull was fradtured, having had all that time very bad fymptoms ; I immediately open- ed the fcalp andlet out about two ounces ofgru- nious blood, and laid the fcull bare about four inches one way, and three the others and tied the blood veifels, that I might make the opera- tion without much difficulty, the next morning. The fra6lure extended aero fs the Os Bregmatis, from the fagittal future, to the temporal bone \ that part next the Os Frontis was deprefled equal to its thicknefs, and a great deal of extras vaiated blood partly turned to matter, lay un- der the other part of the fame bone. I made two perforations with the trephine, clofe to the fradure, that I might raife it up fleadily through both, and have more room for the extravafated blood to difcharge from under the fcull , which had difcharged before in great quantity through the fradlure. But neverthelefs ten days after the former operation, I was obliged to make another perforation, to 'discharge the matter pore freely ; for during a rndnth, the matter ran through all her drefTmgs down her face, tv/ice every day, and was exceedingly fcetid; an4 A Ca/e of a j. ac,i > ed Scud, and for the fpace ot five months the matter decreafed very little in quantity, but grew lefs and lefs o'Tenfive, till September the tiiirteenth, when the lead of the bones- was taken out s Tat.ix. G, and on September the twenty ninth, the large one % after which time the matter was good, Xab.ix D. and not too much in quantity. Both thefe bones are through both Tables, for the motion in the brain was feen •, only feme YmXt parts of the lefTer bone remaining, a callous was formed from them, but v/here the great one came away there v/as none, only a common ci- catrix; and befides thefe, there were many little bits of bone came away in the dreffings : She was foon after cured, and has remained well ever fmce. E 4 TABLE 56 TABLE I. The fore view of a fCeleton. I OsFrontis. % OiTa Pedloris. 3 Clavicula, 4 Scapula. f Os Humeri. 6 Radius, 7 Ulna. 8 Carpus. ^ Metacarpus, lo Spina Dorfi. I I Os Innominatum, 1 2 Os Fembris. 13 Trochanter Majon J 4 Patella. i^ Tibia. 16 Fibula. 17 Tarfus. 18 Metatarfus.. TABLE A/^. Tab I SxtttanlftikolL JCU^. P'.^y- Tab II SvtbmMchclli sculp: J7 TABLE II. The hack view ofafceleton. 1 Os Bregmatis. 2 Os Occipitis. 3 Clavicula. 4 Scapula. 5* Proceflus Acromion, 6 Os Humeri, 7 Radius. 8 Ulna. 9 Olecranon, ID Coftas. 11 Spina. 12 Os Innominatumo 13 Os Sacrum. 14 Os Coccygis. 15 Os Femoris. • 16 Trochanter Major, 1 7 Trochanter Minor, 18 Tibia. J 9 Fibula, * TABLE 58 TABLE IIL The bones of the head. 1 Sutura Coronalis. 2 Sutura Sagittalis. 3 Sutura Lambdoidalis, 4 Sutura Squamofa. 5 Sutura Tranfverfalisy 6 Os Frontis. 7 Os Bregmatis. 8 Os Occipitis, 9 Os Temporis. 10 Proceffus Mammillaris, 11 Meatus Auditorius. 12 Proceffus Styliformis. 13 Proceffus Jugalis. 14 Os Sphenoides. 15 Os Malse. 16 Os Nafi. 17 Os Unguis. 18 Os Planum. 19 Du6lus ad Nafum. 20 Maxilla fuperior. 2 1 Foramen Maxillas fuperioris, 22 Maxilla inferior. 23 Proceffus Coronalis, 24 Proceffus /^'JS Tas 11 59 24 Proceiuis Condyloides. 25 Foramen MxxiRiL iiifarhris, 26 Dentes Incifarii. 27 Dentes Canini. ^8 Pentes Molares. TABLE do TABLE ly. A, The fore view of the fcull. I Sutura Coronalis. 2 Sutura Sagittalis. 3 Sutura Squamofa, 4 Satura Sphenoidalis, 5 Os Frontis. 6 Os Bregmatis. 7 Os Mate. 8 OsN^fi. 9 Maxilla fuperior. B, A View of the-Bafis of the fcull I Satura Lambdoidalis. 2 Os Oecipitis. 3 Os Temporis. 4 Procerus Mammillaris. 5 Proceflus Styloides, 6 Proceflusjugalis. 7 Os Malas. 8 Os Palati. 9 Maxilla fupcrior. ID ProcefTus Pterygoides. C The Os Hyoides, I Bafis. 2 Cornua. D, The Ofla Sefamoidea of the great toe. E, The Offa Sefamoidea of the thumb. F, The ^ 3) 6i F, The fefamoid bone that is fometimes found near the beginning of the Plantaris mofcle. G, The firfl Vertebra. 1 Proceflus Tranfverfus, 2 ProcelTus Obliquus. H, The fecond Vertebra. 1 Procefius Dentatus. 2 Proceflus Tranfverfus. 3 Proceflus Obliquus. 4 ProceflTus Spinalis. i, One of the Vertebrae of the Thorax; 1 Corpus Spongiofum. 2 Proceflus Tranfverfus. 3 Proceflus Obliquus. 4 Proceflus Spinalis. K, Oneofthe Vertebrae of the loins, 1 Corpus Spongiofum. 2 Proceflus Tranfverfus. 3 Proceflus Obliquus. 4 Proceflus Spinalis. L, The bones of the Foot. . I Afl:ragalus. 2 Os Calcis. 3 Os Naviculars 4 Os Cuboides. 5 OsCuneiforme majus." 6 Os Cuneiforme medium. 7 ps Cuneiforme minimum. 8 Metatarfus. 9 Ofla Polliois Pedis. lo Ofla 62 lo Ofia Digit crum Pedis M, The bones of the hand. :} I* 2, 3, 4 5, 6, 7, 8 9 Metacarpus. 10 The bones of the thumb. 11 The bones of the fingers. The eight bones of the Carpus* TABLE ^3 TABLE V. A, Shews the Sceleton of a full grown Foetus, in which may be obferved, the Epiphyfes, the Carpus and Tarfus, which are cartilaginous fhrunk in drying, and the Ihape in general differing from the Sceleton an adult. B, The Scapula of a body twelve years old, 1 An Epiphyfis at the Bafis. 2 The Epiphyfes of its Procefles. 3 The Epiphyfis at the upper end of the Os Humeri from the fame body. C, The Bregma of a Foetus Rvg months old prepared, to Ihew the fibres offifying from a middle point, and fhooting out on every fide. D, The Tibia fawed length-ways. E, The Tibia of a Foetus five months old with the Epipiiyfes off. TABLE 64 TABLE VI. A^ A Diflorted fpine. B, The Os Femoris of a man eight foot high. 1 Shows three Trochanters. 2 A fourth Trochanter. . 3 The Linea Afpera. 4 The two inferior Apophyfes. C, Part of an Os Femoris carious. D, Half the lower jaw exfoliated. E, Part of a carious leg and foot, with all the bones grown into one, 1 The Tibia. 2 The Fibula. F, Part of a thigh-bone. I A bony excrefcence. G, The head of the Os Femoris broke ofF^ which had been miftaken for a luxation. H, Another piece of an Os Femoris with the head broke off -, which was alfo miftaken for a luxation. TABLE <%i^Miti 65 ' TABLE VII. A Bone from the Omentum of a Iheep taken out and delineated by Dr, Steukley. The pricked line fhev/s the places where the bones were united* TABLE 66 TABLE VIII. ■ Represents the infide of the fcull faw'd through longitudinally. 1 Os Frontis. 2 Sutura Coronalis. 3 Sinus Frontalis. 4 Os Bregmatis. 5 Sutura Sagittalis; 6 One of the OlTa Triquetra, 7 A procefs of the Os Occipitis. 8 Part of the Foramen Maximum. 9 The procefs of the occipital bone that ar» ticulates it to the fpine. ID The ninth Foramen of the feulL 11 Os Temporis. 12 Sutura Squamola. 13 Os Occipitis. 14 Os Petrofum. 15 A Foramen, through which pafles the audi- tory nerve. 16 Proceffus Styliformis. 17 Os Sphenoides. 1 8 Sella Turcica. 19 The Suture between the Os Occipitale and Sphenoidale. 20 Aprocefs of the Os Sphenoidale that makes part of the Septum Nafi, 21 Proceffus Pterygoides. 22 Chria .ee. ^^^mt. 6? 22 Crifta Gain of the Os Ethmoides. 23 A procefs of the Os Ethjnoides making part of the Septum Nafi. 24 Os Vomer. 25 OsNafi. 26 The Suture that divides the Maxilla Supe- rior. 27 A perforation in the Maxilla Superion 28 Dentes Inciforii 29 Dens Caninus. 30 Dentes Molares. 31 Sinus Sphenoidaiis F % TABLE 6% T A B L E IX. A, A BONE taken out df the mufcular part of the heart of a man. Vide page 7. B, A bone taken out of the firft procefs of the Dura Mater not far from the Crifta Galli. C,D, The two bones mentioned, page 54. C, Shews the under fide of that part of the Os Bregmatis that was deprefled. D, The piece of bone that feparated laft, and which was not deprefled. E, The two places firll trephined. F, The place laft trephined to give more vent to the matter. TABLE T^. 6^^ix .' ^,^^u^.yhu4^- 5S^^.x 69 TABLE X. The upper and lower jaw, being afpecimeii of an Ofteology in folio, in which every bone will -be done as large as the life. F3 BOOK 71 BOOK II. CHAP. 1. IntroduBhn to the Mufdes. THE mufcles are moving powers, ap- plied to perform the feveral motions of the body •, which they do by con- trading their length, and thereby bringing the parts to which they are fixed nearer toge- ther. The immovable or leall moved part any mufcle is fixed to, is ufually called its origin, and the other its infertion j but mufcles that have their two ends equally liable to be moved, may have either called their origins or infertions. Each mufcle is made up bf a number offmall fibres which Borelli and others have thought to be firings of bladders, and have endeavour- ed to account for mufcular motion by an expan- fion made from an influx of blood and animal fpirits into thefe bladders ; but as the mufcles do not increafe their bulk fenfibly in contrad- F 4 ing. #. 72 ' IntroduB'ton to the Mufcles. ing, there needs no more to be faid to refute this hypothefis. (See Dr. Pemberton's intro- dudion to Cowper on the mufcles.) But Dr. Keii thought that in this v/ay the mufcles might be contraded by a fwelling, fcarce fenfible, if the bladders are but very fmall : For, fays he, fup- pofing a bladder of any determined bignefs can raife a weight a foot, a hundred bladders whof's diameters are each a hundredth part of the former v/ill raife the weight to the fame height ; but the force of inflation and the fwelling of all together will be ten thoufand times iefs, and it will alfo raife ten thoufand times Iefs weight, which he has not obferved-; therefore not one fuch ftring of bladders, but ten thoufand muil be applied to do the fame thing that the one bladder will do : and they will have the fame fwelling, otherwifeit would be eafy to fhew how to make a Perpetuum Mobile of prodigious force. For the difcovery. of this miftake in Dr. Keil, I am obliged to Dr.Oldfield. The mufcles are of two forts, viz. re6lili- neal and penniform. The former have their fibres almofi: parallel in the fame or near the fame dire6lion, with the Axis of the mufcle ; and the latter have their fibres joined in an oblique diredion, to a tendon pafTing in or near the Axis, or on their outfide. The IntrodtiBton to the Mufcles. 7 3 The redlilineal mufcles, if their origins and infertions are in little compafs, are never of any confi'derable thicknefs,unlefs they are very long, becaufe the outward fibres would comprefs the inner ones, and make them almoil ufelefs ; an^ therefore every redilineal mufcle, whofe inner fibres are compreiTed by the outer, have their inner fibres longer than the external, that they may be capable of equal quantity of contrac- tion. The Penniform mufcles, though. they are in a manner free from the inconvenience of one fibre comprefiing another, and though by the o- bliquity of their fibres, nothing is abated of their moment, as is clearly demonftrated by an ex- periment of Mr. Hawkfbee's, where it is fhewn, 'j^^jj ^ji^ that in all cafes, juft fo much more weight as redilineal fibres v/ill raife than obhque ones, the oblique will move their weight with juft fo much greater velocity than the redilineal;^ which is making their moments equal: So that in the ftrudure of an animal, like all mecha- nic engines, whatever is gained in ftrength is loft in velocity, and whatever is gained in ve- locity is loft in ftrength. Yet the fibres of the penniform mufcles becoming more and. more oblique as they contrad, their ftrength decreafes, and their velocity increafes, which makes them lefs uniform in their a6lions than the redilineal mufcles \ wherefore it feems that S naturfe 74 IntroduBion to the Mufcles. nature never ufes a penniform mufcle where a re6lilineal mufcle can be ufed •, and the cafes in which a redtilineal mufcle cannot be ufed, are where the fhape of a mufcle is fuch as that the inward fibres would be too much comprelTed, or where rectilineal fibres could not haveale- ver to a6l with, fuitable to their quantity of contra6lion, which is the cafe of all the long mufcles af the fingers and toes; for every mufcle muft be inferted or pafs over the centre of motion of the joynt it moves, at a diftance proportionable to its quantity of contra<5lion, and the quantity of motion in the joynt moved 5 for if it was inferted too near, then the motion of the joynt would be performed before the mufcle is contraCled all that it can ; if too far off, the mufcle will have done contracting be- fore the whole motion of the joynt is made ; and though the quicknefs and quantity of motion in a mufcle will be, Caeteris Paribus, as the length of its fibres ; for if a fibre four inches long will contract one inch in a given time, a fibre eight inches long will contrad two inches in the fame time ; and the ftrength of a mufcle or power to raife a weight, Casteris Paribus, will be as the number of its fibres ; for if one fibre will raife a grain weight, twenty fibres will raife twenty grains. Neverthelefs , two mufcles of equal magnitude, one long, and the other fiiort, will both move the fame weight with 8 the IntroduB'ton to the Mufcles, the fame velocity when applied to a bone ; be- caufe the levers they ad with muft be as their lengths, and therefore the penniform and Ihort thick mufcles are never applied to a bone for the fake of ftrength, nor long fibred mufcles for quicknefs % for whatever is gained by the form of the mufcle, whether ftrength or quick- nefs, muft be loft by their infertions into the bone, or elfe the mufcles muft not ad all they can, or the bones have \^i^ motion than they are fitted for. I N the limbs feveral mufcles pafs over two joynts, both of which they are liable to move at once, with force proportionable to the levers they ad with upon each joyntj but either joynt being fixed by an antagonift mufcle, the whole force of fuch mufcles will be exerted upon the other joynt ; which in that cafe may be moved with a velocity equal to what is in both joynts, when thefe mufcles ad upon both at once. This mechanifm is of great ufe in the limbs, as I Ihall fhew in the proper places. That only we call the proper ufe and ac- tion of any mufcle which it has without the ne- cefTary afliftance of any other mufcle, and what that is in a mufcle moving a joynt we may al- ways know, and with what force it ads. Ceteris Paribus, by dropping a line from the center of motion of the joynt, it moves perpendicular into the Axis of thd mufcle in any fituationj but in 7S / 6 IntroduB'ton to the Mufcles, m a joynt which admits only of flexion and ex- tenfion, this line mull alfo be perpendicular to the Axis of motion in that joynt, and the adlion of the mufcles will be in the dire6lion of that perpendicular line, and the force with which k ads in any fituation v/ill be CjEteris Paribus as the length of that perpendicular line. • Each mufcle, fo far as it is diilin6l and is moved againft any part, is covered with a fmpotK membrane to make the fri6tion eafy •, but where they are externally tendinous thofe tendons are often fmooth enough to make fuch a covering needlefs. Befides this mxcmbrane there is ano- ther, known by the name of Fafcia Tendinofa, which deferves to be particularly confidered. The ftrong one on the outfide of the thigh, which belongs to the Fafcialis and Gluteus mu- fcles is of great ufe in raifmg the Gluteus far- ther from the centre of motion of the joynt it moves, to increafe its force : in like manner the Fafcia detached from the tendon of the Biceps Cubiti alters its diredlion for the fame pur- pofe, but thofe on the outfide of the Tibia and Cubit, &c. are only flat tendons from which the fibres of the mufcles arifeas from the bones. There are alfo in many places fuch tendons be- tween the mufcles, from which each mufcle arifes in like manner, for the bones themfelves are not fufficient to give origin to half the fibres of the mufcles that belong to themj befides, if Of the Mufcles. 77 if all the fibres had rife from the bones they muft have been liable to comprefsone another" very inconveniently. CHAP. IL Of the Mufcles. OBliqjuus Descendens, arifes lielliy Mafiks from near the extremities of the eight o^^^^eAb- inferior ribs, the upper part of its Origin being XaLxiF©; indented with the Serratus Major Anticus, and the lower laying under a fmall portion of the LatiOlmus Dorfi. It is inferted flefhly into the upper part of the fpine of the Ilium, and by a broad flat tendon (which firmly adheres to a like tendon of the following mufcle as they pafs over the Redus^ into the Os Pubis, and Linea Alba, which is a ftrong tendinous line extended from the Os Pubis to the Sternum, between the Mufculi Re^Sli. O B L I QJJ us AscENDENS, arifes fleihy nnder the former mufcle from the fpine of the Ilium, and is inferted fleiliy in the cartilages of the three loweft ribs, and by a fiat tendon into the Sternum, aud Linea Alba, together •with the tendon of the foregoing mufcle. The line in whichthefe two tendons join on the out- fide 78 Of the Mufcles, fide of the Re6tus mufcle, is called Semilunaris: And though fo much of this mufcle as is in- ferted flelhy runs obliquely upward, yet the middle and lower part is directed tranfverfe and downward; and befide the tendon which it unites with the Obliqus Defcendens, it often detaches another near the Sternum to be infert- ed with the Tranfverfalis under the Re6tus. Tab. xii. Pyramidalis, arifes from the Os Pu- II* bis, and is inferted into the Linea Alba about three or four inches below the navel : This and its fellow are often wanting. Tab. xii. Rectus, arifes tendinous from the Os Pu- JO. bis *, but flefhy when the Pyramidales are want- ing, and is inferted into the lower part of the Sternum near the Cartilago Enfiformis. This mufcle is divided into four or five portions by tranfverfe tendinous iiiterfedlions, that it might conveniently bend when the body is bov/ed forwards, though this mufcle fhould be then in aftion, and thefe interfedbions are chiefly above the navel, where it is moft liable to be bent: befides being thus divided its chief preffure will not be in its middle, but under the feveral bellies of the mufcle, and the greateil below the navel, where is the longeil flelhy belly of this rnufcle, and where the parts in the Ab- domen fe'em to want mofl: to be fupported. Transversa LIS, arifes by a flat tendon from the tranfverfe proceiTes of the lumbal Ver- tebra, Of the Mufcles. 79 tebrae, and flefhy from the infide of the ribs below the Diaphragm, and from the fpine of the Ilium, then becoming a flat tendon, it pafles under the Redus to its infertion into the Linea Alba. Between this tendon and the Peritoneum, fometimes water is found in great quantities, which dillemper is called the drop- fy in the duplicature of the Peritoneum, which fhews this membrane has been miilook for part of the Peritoneum. These fire pair of mufcles all confpire to comprefs the parts contained in the Abdomen. The Obliquus Defcendens on the right fide, and Afcendens on the left ading together,, turn the upper part of the trunk of the body towards the left, 6c Vice Verfa ; but the trunk is chiefly turned upon the thighs: the Redi bend the body forward, and pull the Sternum downward in expiration; the two oblique mufcles and the tranfverfe on each fide near the groins, are perforated to let through the Proceflus Vaginalis with the fpermatick veifelsa Thefe perforations are difl:ant from each other, fo as to fuffer the veflelsto defcend convenient- ly into the Scrotum. ; this way the inteilines or the Omentum, defcend in ruptures. Cremaster Testis, is a fmall porti- Mufcles on of fibres which arifes from the Ilium, and o^ ^^'^^ appears to be part of the Obliquus Afcendens '^^^^^^- mufcle, till it meets with the fpermatick vef- fels 8o Of the Mtifcles. fels at their coming out of the Abdomen, where it begins to defcend with them by the fide of the Proceffus Vaginalis, to the tefticle, over which it is loofely expanded. This mufcle is too fmall to be plainly difcovered' in ema- ciated bodies. ^"Sr Erector Penis, arifes from the Os If- Penis. chium, and is inferted into the Crus Penis near the Os Pubis. It is faid, by preffing the Penis againft the Os Pubis, to comprefs the Vena Ip- lius Penis, and hinder the reflux of blood, whereby the Penis becomes extended and eredl; but it does not appear to me to be well con- trived for that ufe. Accelerator UkiNiE: This, with its fellow, are but one mufcle ; it arifes ten- dinous from the Ofia Ifchia, and flefhy from the SphindcrAni, or according to Mr. Cowper from the fuperior part of the Urethra as it paf- fes under the Os Pubis : and thence being ex- panded over the bulb of the Urethra ; it after- wards divides, and is inferted into the Penis* The ufe of this mufcle is not to accelerate the urine, for that is propel!' d by the Detrufor Urinas, or mufcular coat of the bladder, but to protrude the Semen, which is done only by this -, and it being feated oppofite to the Os Pubis, it feems to be much better fitted to be a re- laxer of the Penis by pulling it from the Os Pubis, than the Erector is for the office affign- ed it. Transver- Of the Mufcles. Tr ANSVERSALis Penis is that part of the former mufcle which arifes from the Ofla Ifchia . c \T TT • Mufcles Sphincter Vesicae Urinari^e is ^^ ^j^^ a fmall portion of mufcular fibres, not eafily bladder^ to be difbinguifhedj running round the neck of the bladder to prevent the involuntary effufion of urine. Detrusor URiNi^, is the mufcular coat of the bladder j its fibres are differently difpofed ; but chiefly terminating in the Sphinc- ter Veficse, whereby it not only prefTes the u- rine forward, but when the bladder is full, be- comes an antagonift to the Sphinder, adling al- moft at right angles. Erector Clitoridis, arifes from the Mufcles Ifchium, and is inferted into the Crus Clitoridis, °.^^^"°t ns. like the Eredbor Penis in men, and is faid, to caufe eredtion in the fame manner. ^\ S p H I N c T E R Va G I N ^, is an order of mu- Mufcles fcular fibres intermixed with membranous fibres of the Va* furrounding the Vagina Uteri near its orifice ; it ^'"^' is cone6led to the OfTa Pubis and Sphinder A- ni ; its ufe is to conflringe the orifice of the Va- gina, to prefsout a liquor from the glands of the Vagina, and embrace the Penis in coition. Dr. Douglas mentions two pair of mufcles of the Vagina of his own difcovering, which I have never difieded, and will therefore give them in his own words : The firfl: arifes from G the of the Anus. 8z . Of the Mufcles. the inner edge of the Os Pubis mid-way be- tween the Ifchion and the beginning of the Crus Ciitoridis, is inferted into the Vagina*, the fecond arifes tendinous and flefhyfrom the Os Pubis internally in common with the Le- vator Ani, is inferted into the upper part of Vagina at the fide of the Meatus Urinarius or Collum Veficse. Mufcles SpHiNCtER Ani, is a mufcle near two inches in breadth, furrounding the Anus to clofe it, and to prevent involuntary falling out of the Fasces. Levator Ani, by Dr. Douglafs, called two pair of mufcles, but Mr. Cowper defcribes the whole as one mufcle only,' which arifes from the OfTa Ifchii, Pubis, and Sacrum with- in the Pelvis, and is inferted round the lower end of the Redum Intellinum. Fistula's in Ano, that are within this mufcle, generally run in the diredlion of the gut, and may be laid open into the gut with great fafety ; but thofe fiflula's, or rather ab- cefTes that are frequently formed on the out- lide of the Sphindier, and ufually furround it, all but where this mufcle is conne6ted to the Penis,, cannot be opened far into the gut, without totally dividing the Sphindler, which. Authors fay, renders the Sphin6ter ever af- ter uncapable of retaining the excrement. One inflance of this kind I have known 5 but Of the Mi^fcles, 83 but Mr. Berbeck, of York, an excellent Sur- geon, and particularly famous for this opera- tion, has afTured me, that he has often been forced to divide the Sphin6ter, which has made the patients unable to hold their excrements during their cure, but the wounds being heal- ed, they have retained them as well as ever. GocGYGEi arife from the acute proceiTes Mufdes of the OiTa Ifchii, and are inferted into the ^^^^^^^^^^ Os Coccygis, which they pull forward. Occipito-Frontalis, is a mufcle Mufdes with four flelliy bellies, commonly named ^^^j Frontales and Occipitales. It arifes behind each Tab.x, h, ear from the Os Occipitis, and foon becorhing tendinous, pafTes under the hairy fcalp to the forehead, where it becomes broad and llefhy,- adhering to the fkin, and is inferted into the upper part of the orbicular mufcles of the eye- lids into the Os Frontis near the nofe, arid by two proceiTes into the bones of the nofe. When this mufcle a6ls from the back-part, it pulls the fkin of the forehead upward, and wrinkles it tranfverfe, and in fome perfons the hairy fcalp backwards \ but when the forepart of it adls, it draws the fkin with the eye-brows downward, and towards the nofe when we frown. The tendon of this mufcle has beeii miftaken for a membrane, and been called Pe- ricranium, and the true Pericranium, Perio- fteumv 84 Of the Mufcles. Mufcles ElevatorAuricul^, arifes from the ternalear* ^^"^^^ ^"^ ^^^ Oceipito-Frontalis, and is in- ferred into the upper part of the ear that is corrnedled to the head. Retractor Auriculae, arifes by- one, two or three fmall portions from the tem- poral bone above the mamillary procefs, and is inferted into the ear to pull it backward. Mufcles Orbicularis Palpebrarum, fur- eyelids, rounds the eye-lids on the edge of the orbit, Tab.x D. and is fixed to the Sutura Tranfverfalis at the - great corner of the eye ; it fhuts the eye-lids, efpecially in winking. That part of this mufcle that lies under the eye-brow is very much intermixed with the Oceipito-Frontalis, and under it from the Os Frontis near the nofe, arifes a fmall portion of diftinft fibres which end in this mufcle, and, I think, are a part of it*, neverthelefs, from the effedt of their A6tion, are not improperly called Mufcultis. Corrugator. CiLiARis, is a very fmall portion of this mufcle, next the ciliary cartilages of the eye- lids. Elevator PALPEBRiE Superioris Rectus, arifes above the optick nerve, from the Peri- ofteum at the bottom of the orbit (as do alfo the five following mufcles) and is inferted into the whole ciliary cartilage of the upper eye-^fid by a very thin flat tendon. Elevator OftheMu/cles. 8j Elevator Oculi, arifes from the bot-Mufcles torn of the orbit, between the optick nerve ^^ and the foregoing mufcle, and is inferred into Tab.x.Q. the upper part of the Tunica Sclerotis of the eye, near the Cornea. Depressor Oculi, arifes , and is in- Tab.x. R. ferted diredly oppofite to the laft defcribed mufcle. Adductor Oculi, arifes from the bot- Xab. x. S. torn of the orbit, near the optick nerve in- ternally, and is inferred into the Tunica Scle- rotis on the fide next the nofe. Abductor Oculi, has both its ori- Tab.x. T. gin and infertion, diredly oppofite to the Adduifcor. OBLiquus Superior Seu Trochlearis, Tab.x. N. arifes between the Elevator and Addudior Ocu- li at the bottom of the orbit, thence afcending by the Sutura Tranfverfalis, becomes a round tendon , which pafling through a pulley at Tab.x. O. the upper and inner part of the orbit near its edge, is inferred near the bottom of the globe of the eye, which it pulls upward and inward, and thereby diredls the pupil outward and downward. O B L I Qjj us Inferior, arifes from the 'p^^^ ^ p^ Os Maxillas Superioris, at the the edge of the orbit \ thence palling over the Deprefibr is in- ferred near the Abdu6tor at the bottom of the eye, but not fo low as the infertion of the Ob- G 3 liquus 86 . Of the Mufcles. iiquus Superior: It turns the pupil upward and outward. These mufcles are inferted with grear Advantage to move a fmall weight, and are very long, that the eye may be moved with fafiicient quicknefs. The two oblique mufcles are an Axis to the motions of the other four, and afting ftrongly againil them, (which a6li- on I take to be what is vulgarly called drain- ing the eye) may, I think, bring the cryftal- Inie humour nearer to the Retina, and even jTiake the cryftalline humour more flat to fit the eye for objects at a great diflance ; for this end it feems to me that there are fix mu- fcles thus difpofed, when three would be fuf- ficient to turn the eye every way, if it was in a fixed focket ; and it feems alfo that v/hile the mu- fcles are all thus in aftion, the fuperior oblique in each eye fets the pupil farther from the nofe, while the inferior oblique direds it upward ^ the firft of which adions is alv/ays necefiary, and the latter often fo, when v^e look with both eyes at very diflant objeds ; and when the two oblique mufcles grow weak by age or difeafe, or ceafe to ad at all, as in paralytick cafes, and death, then the eye finks in the orbit. Mufcles Sphincter or Constrictor Oris, of the fijrrounds the mouth about three fourths of an Tabx. E. i^ch broad. This mufcle is very much inter- mixed with all the mufcles that are infertecj itito ito ' Ele- Of t!:'' Vuicki %7 Elevator Labii Superi oris Pro- Tab. x. F, PR I us, arifes from the bone of the upper jaw under the anterior and inferior part of the Or- bicularis Palpebrarum, and ufually takes ano- ther fmall beginning from the Os Mal^, which fcems as if it was fcnt off from the Orbicularis Palpebrarum; and paffing down by the fide of the nofe, into which it fends fome fibres, is in- ferted into the upper part of the Sphinder Oris, This raifes the upper lip, and helps to dilate the nofbrils. DepressorLabii Superioris Pro- PR I u s, is a fmall mufcle arifmg from the upper jaw near the Dentes Inciforii, and is in- ferted into the upper part of the lip and root of the cartilages of the nofe ; hence it is alfo a deprelTor of the nofe, which adlion conftridls the noftrils. Depressor Labii InferiorisPro- '■^^ ^^^^^ p R I u s , arifes broad from the lower jaw at the I. chin, and is foon inferted into the Sphinder Oris ; the order of fibres in this feems not fo confpicuous as in the other mufcles of the face. Elevator Labii Inferioris Pro- PR I us, arifes from the lower jaw, near the Dentes Inciforii, and is inferted into the low- er part of the lip. Elevator Labiorum pOMMUNis, Tab. xiii, arifes from a deprefiied part of the Superior ^* G 4 Maxilla. 88 Of the Mufcles. Maxilla under the middle of the orbit, and is inferted into the Sphindter mufcle near the corner of the mouth, Tab.xiii, Depressor Communis Labiorum, arifes laterally from the lower jaw near the chin, and is inferted into the Sphindler, oppofite to the former. Tab.xiii, Zygomatic us, arifes from the anterior ' part of the Os Zygoma or Malas, and frequent- ly derives a portion of fibres from the Orbicu- laris Palpebrarum, thence running obliquely downwards J it is inferted into the Sphinder at the corner of the mouth, betwixt the Elevator Communis and Buccinator ^ it draws the corner of the mouth outward and upwar4. When thi^ mufcle grows weak, the corner of the mouth fmks, as may be obferved in old per- fons. Tab.xiii. Buccinator, arifes from the ProcefTus ^* Corone of the lower jaw, and pafllng contiguous to both jaws, is inferted into theSphinder mu- fcle at the corner of the mouth. It ferves ei- ther to force breath out of the mouth, or thrufl: ■ the aliment between the teeth in maflication, or to pull the corner of the mouth outward. Platysma Myoides, arifes loofely from over the peroral and part of the deltoid mufcle, and running obliquely forward, is in- ferted into the chin, and deprefTor mufcles of |:he lips. This mufcle being exceeding thin (a Of the Mujcles. 89 mere Membrana Carnofa) ferves to cover the unequal furface of the fubjacent mufcles, and render the neck even -, it alfo pulls down the corner of the mouth, and from its infertion at the chin, may contribute to the pulling down of the lower jaw. RetractorAl^Nast, is a very fmall Mufcles mufcle arifmg from the bone of the nofe, and ^^^^^ is inferted into the fkin and cartilage at the fide of the nofe. Mylohyoipeus, with its fellow, may Mufcles be efteemed one penniform or elfe a digailrick Hyo^des. mufcle : It arifes from the Linea Afpera on the infide of the lower jaw and Proceflus Innomina- tus, both fides meeting at about right angles in a middle line upon the following mufcles, \t is inferted by a fmall portion of fibres into the Bafis of the Os Hyoides^ it moves the tongue upward and forward, and alfo compref- fes the following mufcles, whereby they raife the tongue more commodioufly, and alfo hin- ders them from drawings the Bafis of the Os Hyoides into a right line betwixt the chin and Sternurn at fuch times as the Stylohyoids can» not ad. Geniohyoideus, arifes from the Pro- ceflus Innominatus of the lower jaw, under the foregoing mufcle, and is inferted into the Bafis pf the Os Hyoides, which it pulls upward and forward^ po Of the Mufcles. forward. This with its fellow, are for the moll part but one mufcle. Stylohyoideus, arifes from the Procef- fus Styliformis near its root, and paffing con- tiguous to the horn of theOs Hyoides becomes inferted lateraly into its Bafis. This mufcle is fometimes perforated about the middle by the tendon of the digaftrick mufcle of the low- er jaw. Its ufe is to pull the Os Hyoides up and backward. _, .. CoRACOH YoiDEUS, arifes from the up- Tab. xu. ' r 3. per Cofta of the Scapula near the ProcefTus Co- racoides, and pafTmg under the Maftoideus mufcle becomes in that place a round tendon ; thence paiTmg almoft parallel to the following mufcle, is infetted together with it into the Bafis of the Os Hyoides; this draws the Os Hyoides downward, and a little backward. I have once feen one of thefe mufcles wanting^ and the Sternohyoideus arifmg from the mid- dle of the clavicle on that fide. Sternohyoideus, arifes from a rough- nefs at the under part of the Clavicula near the Sternum, and the cartilaginous part of the firft: rib; and is inferted into the Bafis of the Os Hyoides, to pull it downward. Genioglossus, arifes from the Procef- of^the^^ fus Innominatus of the lower jaw, and is in- tongue, ferted broad into the under part of the tongue, to Tab. xii. >.aiiaiMi»i 1 ^ Of the Mufcles, 9 1 ■■ • ■' - — '-' ' = ' — — r" to pull it up and forward, and fometimes has a fmall infertion into the Os Hyoides. Basioglossus feems a portion of the former mufcle, it arifes from the Bafis of the Os Hyoides, and is inferted into the tongue nearer its tip. Ceratoglossus, arifes from the horn of the Os Hyoides, and is inferted laterally in- to the tongue near its root, to pull it down- ward and forward. Styloglossus, arifes from the extremi- ty of the ProcelTus Styiiformis, and is inferted into the tongue near the former to pull it up and backward. I have very often found ano- ther ftyloid mufcle fo inferted, that I cannot tell whether to call it a mufcle of the tongue or Pharynx. The Tongue is a mufcle made of fibres, longitudinal, circular, and tranfverfe, fo inter- mixt as beil to ferve its feveral motions.. H Y OTHYROIDEUSOrCERATOTHYROI- MufcleS DEUs, arifes from part of the Bafis, and the °^^^^^ horn of the Os Hyoides, and is inferted into xhyroi^ the lower part of the Cartilago Thyroides, to ^es. pull it upward. Sternothyroideus, arifes from the infide of the Sternum , and is inferted with the former •, it pulls the thyroid cartilage di- rectly downward. Crico- Eoides. 92 Of the Mufcles. Cricothyroideus, arifes from the an- terior part of the Cartilago Cricoides, and run- ning obliquely upward and outward, is foon inferted into the infide of the Cartilago Thy^ roides, which it pulls towards the Cartilago Cricoides. Both this mufcle and its fellow, for the moil part appear double. Mufdes Cricoaryt^noideus Posticus, a- Cartilago ^'^^^^ ^^^^ ^^ back-part of the Cartilago Cri- Arytse- coides, and is inferted into the Aryt^enoides to pull it backward. Cricoaryt^enoideus Lateralis, arifes laterally from the Cartilago Cricoides, and is inferted laterally into the Arytsenoides. This with its fellow, pull down each cartilage toward their origin, and thereby dilate the Rimula. THYROARYTiENoiDEUS, arifes from the fuperior, middle, and inner part of the Cartilago Thy roides, and is inferted with the former into the Arytasnoides cartilage to di- late the Rimula. Thefe two laft defcribed mufcles are not naturally divided, and there- fore ought to be accounted but one mufcle. A R Y T .s N o I D E u,s , is One fmgle mufcle arifing from one aryt^noidal cartilage, and is inferted into the other to draw them together, and clofe the Rimula. Thefe few fmall mufcles of the tongue and Larynx, with only one pipe, make a greater variety of notes and founds than can be made by artificial inftruments, and that in Of the Mufcles. 93 ■ ■ " in a manner fo little underftood by us, and by organs fo little differing from thofe in quadru- peds, that for ought we know of them, brutes might be a^ capable of all thefe founds as men. Stylopharyngeus, arifes from near ^^ ^^^ the bottom of the ProcefTus Styloides of the Pharynx.' Os Petrofum, and running obliquely down- ward, is inferted into the Pharynx. This mu- fcle with its fellow, pulls up and dilates the Pharynx to receive the aliment. QEsoPHAGEUS, arifes like a wing from feveral parts of the fcull, tongue, Os Hyoides, the cricoid and thyroid cartilages, and is in- ferted into the Pharynx. This with its fellow, conftringe the Pharynx, and prefs the aliment down the gullet. MuscuLus Vaginalis GuL^, is the mufcular coat of the Gula. Pterygopharyngeus, is not a di- ftind mufcle, but the beginning of the Pha- rynx near the ProcefTus Pterygoides, of the fphenoidal bone. PtERYGOSTA PHY LINUS In TERN US, MufcleS arifes from the Os Sphenoides, near the Iter p^iau! ad Palatum, or Euftachian tube, and is inferted into the Uvula, which it pulls up while we breath through the mouth or fwallow. P T E R Y G O S T A P H Y L I N us E X T E R N US, arifes by the fide of the laft defcribed mufcle, and is alfo inferted near it j but becomes its anta- 94 Of the Alufcles. aa' ' " ' ^ I I I III > I • 1 II , antagoniil by being refle6led on a pulley, over a procefs at the lower part of the pteiygoidal proceffes of the fphenoidal bone. Gloss o-S taphylinus, is a very fmall portion of mufcular fibres, v/hich pafs from the tongue to the palate, which it pulls down when we breathe through the nofe. The palate it felf is a fort of doable mufde, whofe action feems only to fupport it felf and allill thofe mufcles which pull it upwards. Mufdes DiGASTRicus, arifcs from the Sinus of ot the - ^ . ^ _^ lower the mamillary procefs of the Os TemporiSy jaw. 2Jidi from a flefhy belly, becoming around ten-^ don, paiTes through^ and fometimes under the Stylohyoideus mufcle ; and then being tyed- down by a ligament to the OsHyoides, grows flefhy, and is fo inferred into the anterior part of the lower jaw internally. This mufcle's di- redlion being altered by its being tyed to the Os Hyoides, where it makes an angle, (and not at its pafTage through the Stylohyoideus) pulls the lower jaw downward with much great- er force than otherwife it could have done : and being conneded to the Os Hyoides, when it a6ls it prevents the action of feveral mufcle& which are concerned in fwallowing *, whence it is that we cannot fwallow at the fame time, that we open the jaw, as thofe brutes can" whofe digaflric mufcles are not conneded ta that bone. TfiMPO- Of the Mufcles. 95: Tem po R A L I s, arifes from the Os Frontis, Tab. xiii. Parietale, Sphenoides, Malse and Temporis, * and pairing under the two procefies named Os Jugale, is inferted externally into the Pro- ceiTus Coronas of the lower jaw, which it pulls upward. This mufcle is covered with a ftrong tendinous Fafcia. Masseter, arifes from the lower edge Tab. xiil. of the Os Mal^ or Zygoma, and the procefs ^* which joins this from the temporal bone, and is inferted to the outer part of the angle of the lower jaw, which it pulls up and forward. Thefe two laft defcribed mufcles having dif- ferent Directions, when they adl together, make a fleady motion in the diagonal of their directions. PterygoideusInternus, arifes from the ProcefTus PterygoideusExternus, and from the Sinus between the pterygoid procefles, and is inferted internally into the angle of the lower jaw, which it pulls upward. Pterygoideus ExTERNUS,arifesfrom the Os Maxillare, and Os Sphenoides, near the root of the external pterygoid procefs, and is inferted internally into the ProcefTus Con- dyloides of the lower jaw, which it pulls to one fide, and forwards, or adling with its fellow pulls the jaw dire6tly forwards. SuBCLAvius, arifes from the fuperior Mufde part of the firft rib, and is inferted into more S!,{ ^^^ , . 3 than ^6 Of the Mufcles. than half the underfide of the clavicle next the Scapula. Its ufe is to draw the Clavicula to- ward the Sternum, that they may not be fe- vered in the motions of the Scapula. Mufcles Trapezius, arifes from the Os Occipitis, Scapula. ^^^ from a Linea Alba Colli, from the fpinal Tab. xiii. procefs of the laft Vertebra of the neck, and the ten uppermoft of the back, and from a Li- nea Alba between all thefe Proceffes, and is inferred into one third of the clavicle next the Scapula, almoil all the back part of the fpine of the Scapula, and as much of the Pro- Ceflus Acromion as lies between the fpine of the Scapula and the clavicle. This mufcle draws the Scapula dire6lly backward. I T is generally faid by authors, that the fe- veral parts of this mufcle a6l at different times, and fo pull the Scapula different ways, as ob- liquely upward, downward or backward; but, I think, if that happened, it muft necelTarily di- vide this mufcle into diilind: portions, thofe that contrad always feparating from thofe that do not. Tab. xiii. Rhomboides, arifes tendinous under the 4. former from the fpinal procefs of the Inferior Vertebra of the neck, part of the Linea alba Colli, and from the fpinal procefTes of the four or five uppermoft Vertebra of the Thorax, and is inferred into the Bafis of the Scapula, which it pulls up and backward. The upper 3 part Of the Mufcles. 97 part of this mufcle arifing from the neck, is in many bodies, by the motions of the neck, fe- parated and made a diftind mufcle. Elevator Scapula, arifes from the tranfverfe ProcefTes of the four fuperior Verte- bra of the neck, and is inferted into the upper angle of the Scapula. Serratus Minor Anticus, arifes under the Pedoralis, from the third, fourth and fifth ribs, and is inferted into the ProcefTus Coracoides Scapulse ; which it pulls forward and downward. This mufcle is always faid to be an Elevator of the ribs, though it arifes from the Scapula, which is fupported by the ribs. Seurratus Major Anticus, arifes from the anterior part of the eight fuperior ribs, and is inferted into the Bafis of the Scapu- la, which it draws forward, and by that means moves the focket of the Scapula upward. This mufcle has been always accounted an Elevator Coftarum, though each portion of it is nearly parallel to the rib it rifes from. All the mufcles inferted into the Bafis of the Scapula, are alfo inferted into one ano- ther. Pectoralis, arifes from near two thirds Mufcles of the Clavicula, next the Sternum, and all the ^ ^^" length of the Os Pectoris,, and from the carti- xab.xii.7.' lages of the ribs, and is inferted into the Os H Humeri, 98 Of the Mufcles. Humeri, between the Biceps di^xd the infertion of the Deltoides. The ufe of it is to draw the arm forward. A fmall portion of the lower part of this mufcle is often confounded with the ObHquus Defcendens Abdominis ; and in fome bodies, neither the upper part, nor its tendon, can be eafily feparated from the Del* toides-, and in others, even that part of it that arifes from the Clavicula, is a diftin^ portion. Near the infertion of this mufcle, the fibres crofs thofe from below, ending above in the arm, and thofe from above below, that the tendon of this mufcle might not lie inconveni- ently low between the arm and Thorax, as it would have done, had the fibres which arife loweft from the Sternum been inferted loweft in the arm : but this crolTmg does not make the tendon at all flronger, as is often faid ; nor can I fee how it came to be thought that this ttndon Ihould want more ftrength in propor- tion, than other tendons. «. , . . , Deltoides, arifes exadly oppofite to the infertion of the Trapezius, from one third part of the Clavicula, from the Acromion and fpine of the Scapula, and is inferted tendinous near the middle of the Os Humeri, which bone it lifts diredlly upward. The outermofl parts of this m^ufcle, when the arm hangs down, lie below the center of motion of the joint , jjind therefore can have no fhare in lifting the Humerus Of the Mufcles. ^() Humerus up till it is raifed part of the way by the other part of this mufckj and the fol- lowing mufcle ; and as the outer parts of this mufcle begin to a6l, the following mufcle a6ls with lefs advantage : And it feems to me, that the fole reafon why this mufcle is made of fo inariy parts, is, that they may ad independent- ly; for it is demonflirable , that this mufcle, when the whole of it adts, cannot raife the arm with fo great advantage as a right-lined mufcle bf the fame magnitude would have done. SupRASPiNATUs, arifes from the Dor- fum Scapulse above the fpine, and pafling be- tv/een the two proceifes, is inferted into the tipper part of the Os Humeri, which it helps to raife, until it becomes parallel with the Spi- na Scapula. The Suprafpinatus, the Deltoides and Co- racobrachialis, affift in all the motions of the Humerus, except deprelTion; it being neceHa- ry that the arm Ihould be raifed and fuftained, in order to move it to any fide. Infraspinatus, arifes from the Dor- Xab. xiii. fum Scapula below the fpine, and is inferted S* (wrapping over part of it) at the fide of the Head of the Os Humeri ; it turns the arm fu- pine and backward ; for there is a prone and fupine rotatory motion of the Humerus of near 90 Degrees. H £ Teres lOo' Of the Mujcles. TEREsMiNoit,isa fmall mufcle arifmg below the former from the Inferior Cofta Sea- pulse, and is inferted together with it. It affifts the former in turning the arm fupine, but pulls it more downwards. Tab.xiii. Teres Major, arifes from the lower an- 7- gle of the Scapula, and is inferted at the un- der part of the Os Humeri about three fingers breadth from the Head. This draws the Os Humeri toward the lower angle of the Scapula, and turns the arm prone and backward. Tab. xiii. Latissimus Dorsi, arifes by a flat ten- ^' don from the fpinal procefTes of the feven or eight inferior Vertebrse of the back, and thofe oftheloyns, Sacrum and Ilium ^ and growing flefhy after it has paffed the extenfors of the trunk, receives another fmall flefhy beginning from the ninth, tenth and eleventh ribs, and is inferted into the Os Humeri, with the for- mer. This turns the arm backward and prone. The tendon of this mufcle ferves for a mem- brane to the extenfors of the back, and is con- neded to the tranfverfe procefTes of the Ver- tebra Lumborum. SuBSCAPULARis, arifes from the hol- low fide of the Scapula, which it fills up, and is inferted into the head of the Os Humeri, wrapping fomewhat over it. This pulls i:he arm to the fide, and prone. Cora- Of -^be Mufcles. joi Cor AGO B R AC HI A LIS, arifes from the Proceffus Coracoides Scapulse, in common with the infertion of the Serratus Minor Anti- cus, and is inferted into the Os Humeri inter- nally about its middle. This raifes the arm, and turns it fomewhat outward. Biceps Cubiti Flexor, arifes withMufdes two heads, (that the fibres of this mufcle might ^^ ^^^ .not comprefs one another;) one from theProcef- ^ab. xii. fus Coracoides Scapulae, in common with the ii« Coracobrachialis mufcle, and the other by a round tendon from the edge of the Acetabulum Scapula, which pafling in a Sulcus of the Os Humeri, afterv/ard becomes flefhy, and joyns the firfl head to be inferted with it into the tubercle of the Radius; and fometimes this mufcle has a third head, which arifes from the middle of the Os Humeri. This mufcle lifts up the Humerus, bends the cubit, and has as great a Ihare as any one mufcle in turning the cubit fupine ; the Humerus being fixed by o- ther mufcles, the whole force of this mufcle will be exerted upon the cubit, or the cubit being fixed by an Extenfor, the whole force of it will befpent in raifingthe arm, and therefore ought to be always reckoned among thofe that raife a weight at arms length. A pun6ture of the tendinous expaniion of this mufcle is fuppofed to be always attended with grievous pain and inflammation, and has, if we have H 3 not loz Of the Mufcles. not miflakenthe caufe, fometimes proved mor- tal j yet the beft of furgeons, and particularly Mr. Cowper, has given us inflances of larger tendons being cut and flitched, without any bad fymptoms; and I have often feen them ulcerated and mortified, without any more fign , of pain than in other Parts : So that I cannot fee. what the great Mifchief of pricking this tendinous Fafcia is owing to, unlefs its lying fo much upon the ftretch, which may be whol- ly avoided by bending the elbow, and turn- ing the cubit prone. Since I have confidered this cafe, I have met with only one, which was thus injured by an injudicious blood-letter, who ordered the patient to keep her arm ex- tended for fear of a contra<5lion, and Ihe was not without the mofb violent pain for a whole fortnight; but upon bending the cubit, and turning the arm prone, fhe grew prefently eafy^ and, in a few days, well. Neverthelefs, I am perfuaded that mofl of the accidents which are thought to be merely from blood'^letting are critical difcharges of fome Difeafe, and from the pundure a fmall inflammation beginning, encreafes and fuppurates: But however lingu- lar I may be thought in this opinion, I can be fure I am difinterefted in it, having never had any ill accident follow blood-letting in my life. .. Bracheus Inter Nus, arifes frombelow 13. * * the middle of the Os Humeri, and is inferted into Of the Mufcks. 103 '■■■11. . , .-. !JJi I . _,. _ ' , , , - ' into a rough place of the Ulna immediately be- low the jundlure. This alfo bends the cubit. Supinator Radii Longus, arifes from the lower and outer part of the Os Hu- meri, and is inferted into the upper fide of the Radius, near the Carpus. This mufcle is not a Supinator, but a bender of the cubit, and that with a longer lever than either of the two former mufcles, and is lefs concerned in turn- ing the cubit fupine, than either the extenfors of the Carpus, fingers or thumb. Triceps Extensor Cubiti , com- ^ab. xiii. monly diilinguilhed into Biceps and Bracheus 9. Externus, The firft of thefe heads arifes from the lower Cofta of the Scapula near the Aceta- bulum ; the fecond from the outer and back- part of the Os Humeri ; the third, lower and more internal; and are inferted into the Pro- cefius Olecranon of the Ulna. The firft of thefe heads draws the arm backward, with as long a lever as it extends the cubit. Anconeus, arifes from the outward ex- ^ , ... tuberance of the Os Humeri, and is inferted 10, into the upper part of the Ulna : This is alfo an Extenfor, Palmaris Longus, arifes fmall from the inner extuberance of the Os Humeri, and ^f ^j|g^^ from a fhort belly foon becomes a tendon. Palm of which is connedled to the Ligamentum Tranf- ^^® ^^^^» verfale Carpi, "and expanded in the palm of H 4 the P^^^'^mmmmmmm 104 Of- the Mujcles. the hand. This mufcle is often wanting, but the expanfion in the hand never ; yet it being conneded to the ligament of th<^ Carpus, it mull bend the Carpus, and cannot conflrid: the palm of the hand; and when it is wanting the Flexor Carpi Radialis is larger. Palmaris Brevis or Caro Qua- dra t a, arifes obfcurely from the Ligamen- tum Tranfverfale Carpi, and feems to be in- ferted into the eighth bone of the Carpus and the metacarpal bone of the little finger. This helps to conflridl the palm of the hand, and is very different in fize in different bodies. Mufclss Flexor Carpi R adi ali s, arifesfrom pi the ' the inner extuberance of the Os Humeri, and Mrpus. {qq^ becoming a flrong tendon, paiTes through a chanel of the fifth bone of the Carpus, and is inferted into the metacarpal bone of the fore-finger; this not only bends the Carpus upon the Radius, but alfo the bones of the fecond order upon thofe of the firft; which motion is nearly as much as that upon the , Radius. Flexor Carpi Ulnaris, arifes from the fame extuberance with the former, and a Fafcia betwixt this mufcle and the Tenfor Ul- naris, contiguous to the Ulna, and is inferted by a fhort tendon into the fourth bone of the Carpus, Of the Mufcles, loy* ExTENSOREs Carpi Radial es; the Tab. xiii. firfl arifes from the Os Humeri immediately ^2.. below the Supinator Radii Longus, and is in- ferted into the metacarpal bone of the firfl fin- ger; the fecond arifes immediately below this, from the outer extuberance of the Os Humeri, and is inferted into the metacarpal bone of the fecond finger. The firfl of thefe mufcles is a bender of the cubit as well as an Exten- for of the Carpus, and its often adting with the benders of the cubit while the other is not in adion, is the reafon why it is fo diflind: from it. Extensor Ulnaris, arifes from the fame extuberance with the former, and half the Ulna below the Anconeus mufcle ; then be- coming a tendon, runs in a fmall Sinus at the bottom of the Ulna, and is inferted into the metacarpal bone of the little finger. See Ulna. page 36. The extenfors of the Carpus being inferted into the Metacarpus at once perform the motion between the bones of the Carpus, and that between the Carpus and Radius. The Flexor and Tenfor Ulnaris a6ling together turn the hand downward, the Tenfor and Flex- or Radialis upward. Perforatus or Flexor Secundi Mufdes Inter^odii Digjtorum, arifes from the of the inner tubercle of the Os Humeri, and from the *"^^*'''* ppper part of the Ulna, and the middle of the Radius , io6 Of the Mufcles. Radius; then becoming four ftrong tendons, pafFes under the Ligamentum Tranfverfale Car^ pi, and is inferted into the beginning of the fe^ cond bone of each finger. Perforans or Flexor Tertii In- TERNopii DiGiTORUM, arifcs from half the Ulna, and a great part of the ligament be^ tween the Ulna and Radius, then becoming four tendons, pafTes under the Ligamentum Tranfverfale Carpi, and through the tendons of the former mufcle to their infertion into the third bone of each finger. The tendons of both thefe mufcles are tyed down to the fin- gers by a ftrong ligament. If thefe mufcles had not palTed one through the other, the Perforatus, which is the lefTer mufcle, muft have gone to the laft joint, where the ftrong- er mufcle is wanted; and befides, the tendons of the fecond joints would have prefted thofe that bend the laft, and not lain firmly upon them neither. LUMBRICALES Or F L EXO R ES P RIM I *1nternodii Digitorum, arife from the tendons of the laft mentioned mufcle, and are inferted laterally toward the thumb into the beginning ofthefirft bone of each finger. Tab xiii Extensor Digitorum Communis, 13. arifes from the outer extuberance of the Os, Humeri, and pafling under a ligament, at the wrift, is divided into four tendons which com- municate Of the Mufcles. 107 municate upon the firft joint, which keeps them from (liding off the joints of the fin- gers, where they are a little connedled to the firft bones, and afterward are inferted into the beginning of the fecond bone of each finger. ExTpNSOR Auric LARis or Minimi D I G I T I, is a portion of the laft mufcle paf- fing under the ligament in a diftind chanel. Extensor Indicis, arifes from the middle of the Ulna, and paffing under the li- gament of the Carpus, is inferted with the Ex- tenfor Communis into the fore-finger. This mufcle extends the fore-finger fingly. I have twice feen it wanting. Abductor Primi Digit i, Interos- $Ei and Abductor Minimi Digiti, are eight mufcles, one for each fide of each linger. Adductor PrimiDigiti, arifes from the firft bone of the thumb, and the fide of the metacarpal bone of the firft fin- ger. The I N T E R o s s E I, are three pair fitly divided into external and internal ^ the exter- nal arife from the metacarpal bones, whofe fpaces they fill up next the back of the hand ; the internal arife from the fame bones in the infide of the hand. Abductor Minimi Digit?, arifes-from the tranfverfe ligament, and fourth bone of the Carpus; thefe mufcles are inferted^ two into the firft joint of each fin- ger, and then paffing obliquely over the tops ^ of io8 Of the Mufcles. I'll I L of the fingers are inferted into their laft bones-, they bend the iirft joints, and extend the two lafl, as in holding a pen, and in playing upon fome mufical inflruments. The Abdu6tors of the fore and little fingers, with the fecond and fifth InterofTei mufcles ading, the fingers are divaricated , and the other"^ four acting bring them together, and tfiefe mufcles which diva- ricate the fingers , being extenders of the fe- cond and third joynts, we never can divaricate them without extending them a little. Adductor OssisMetagarpi Mi- nimi Digit I, arifes from the eighth bone and tranfverfe ligament of the Carpus, and is inferted into the metacarpal bone of the little finger, which it pulls toward the thumb to conftri6i: the palm of the hand. Mufcles ExtensorPrimiInternodii Pol- of the L I c I s, arifes from the Ulna below the Anco-- thumb, ^g^g mufcle, and the ligament between the Ulna and Radius; then becoming two, three, or four tendons is inferted into the fifth bone of the Carpus , and firfl of the thumb. The firil of thefe Infertions can only afTifl the bend- ing of the wriil upward, and in turning the arm fupine. Extensor SecundiJnternodii Pol LI CIS, arifes immediately below the former from the Radius and tranfverfe liga- ment, and is inferted by a few fibres into the fecond Of the Mufcles. 109 - ■ fecond bone of the thumb, but chiefly into the third. ExtensorTertii InternodiiPol- LI CIS, arifes immediately below the lail: de- fcribed, from the Ulna and ligament, and paf- fes over the Radius nearer the Ulna to be in- ferted at the third bone of the thumb: This ex- tends the thumb more toward the Ulna than the former mufcle, and is very much a Supi- nator. Flexor Primi & Secundi Ossis P o L L I c I s , arifes from the fifth bone and tranfverfe ligament of the Carpus, and from the beginnings of the two firft metacarpal bones, and is inferted into the whole length of the firft bone of the thumb, and tendinous into the beginning of the fecond ; the fefamoid bones of the thumb, in fuch bodies as have them, lie in this tendon, where it pafTes over the joint. FlexorTertiiInternodti Pol- Licis, arifes large from almoft all the upper part of the Radius, and becoming a round ten- don palTes under the Ligamentum Tranfver- faie Carpi to be inferted into the third bone of the thumb : This mufcle flngly adling, draws the thumb towards the metacarpal bone of the little finger-, but the laft mentioned mufcle ading with it, turns it toward the fore-fin- • Adductor no Of the Mufcles. Adductor Pollicis, arifes from the Carpus, andalmoft the whole length of the me- tacarpal bone of the long finger, and is infert- ed into the beginning of the fecond bone of the thumb; This mufcle naturally enough divides into two, and might better be called a Flexor than Addud:or. A BD u c T o R P o L L I c i s , arifes from the fifth bone and Ligamentum Tranfverfale of the Carpus, and is inferted laterally in the begin- ning of the fecond bone of the thumb to draw • it toward the Radius. The mufcles which bend the thumb are much lefs than thofe which bend the fingers; neverthelefs, the thumb is able to refift all the fingers, merely from the advantages that arife from the thicknefs and Ihortnefs of the bones of the thumb, compared with thofe of the fin- gers •, but then the quicknefs of motion in the fingers will exceed that of the thumb, as much as the fingers exceed the thumb in length, and their mufcles thofe of the thumb in large- nefs. -. -, Supinator Radii Brevis, arifes from of the the outer extuberance of the Os Humeri and Radius, upper part of the Ulna, and running half round the Radius, is inferted near its tu- bercle. Pronator Teres, arifes from the in- ner Apophyfis of the Os Humeri, and upper and Of the Mufcles. Ill and forepart of the Ulna, and is inferted tendi- nous into the Radius below the former. Pronator Quadratus, arifes from the lower edge of the Ulna near the Carpus, and pafling under the flexors of the fingers, is inferted into the Radius. These mufcles are occafionally aflifled in their actions by the mufcles of the hand ; moft of the extenfors alTifting the fupinators , and moft of the flexors the pronators, and moft of the extenfors of the hand take a great part of their origin from the tendinous Fafcia that co- vers them. Mastoideus, arifes tendinous from the Mufcles Sternum near the Clavicula, and by a feparate of the flefhy portion from the Clavicula, which foon ne?k.^^ unites with the other beginning, and is infert- Tab.xii.i, ed to the outer part of the maniillary procefs of the temporal bone. It pulls that fide of the head it is inferted into towards the Sternum, and turns the face over the contrary ftioulder. This with its fellow, pull the head and neck toward the breaft, and a6b with a much long- er lever upon each lower Vertebra, than they do upon the next above, and with more pow- er upon any of thofe bones than upon the head. This mufcle being inferted into the head, beyond the center of motion of the head with the firft Vertebra, has been fuppofed by Mr.Cowper, and others, to pull the head backward; I IX Of the Mufcles. backward ; but paffing beyond fignifies no- thing to that purpofe, unlefs a Hne paffing through its Axis woul'd pafs below the center of motion : And it is the more to be wonder- ed hov/ this miflake prevailed, if we confider that this mufcle's being added to the extenfors of the head and neck, would make the force of that adlion a hundred times greater than that of the benders. And if this is not enough to convince, let any one lying on his back' raife Ms head, and he will foon feel this mufcle in aftion •, but bowing the head forward in an e- red pofture will not fhew this, unlefs fome re- fiilence is made to the head, becaufe the cen- ter of gravity of the head lying before the center of motion, there needs no more than a relaxation of the extenfors, to bring the head forward in that pofture. RectusInternus Major, arifes from the anterior part of the tranfverfe procelTes ©f the third , fourth, fifth and fixth cervical Vertebrse-, and paffing over the two fuperior, is inferted into a roughnefs of the occipital bone near the fore-part of the great Foramen. This bends the head on the two firft Verte- brae of the neck. Rectus Minor Internus, arifes un- der the laft mufcle, from the firft Vertebra, and is inferted under it into the Os Occipitis. This bends the head on the firft Vertebra. Rectus Of the Mufcles. 1 1 3 rm-||"r- - ■- n |-|[ i.ll -■ Ill 11,1 I ., , ^, , . ^ Rectus Lateralis, arifes from the anterior part of the tranfverfe procefs of the firfl Vertebra of the neck, and is inferted into the Os Temporis and Occipitis between the mamillary and ftyloid procefTes. This turns the head to one fide. Splenius, arifes by a thin tendon from the fpinal procelTes of the five fuperior Verte- bras of the Thorax, and the loweft of the neck, and Linea Alba Colli, arid is inferted into the Os Occipitis, the upper part of the Mamilla- ry procefs of the temporal bone, and the tranfverfe procelTes of the three fuperior cer- vical Vertebrae. This pulls the head and neck backward, and to the contrary fide ; but both of thefe adbing together pull them diredly backward. CoMPLEXus, arifes from the tranfverfe procefTes of the fix or feven fuperior Vertebrae of the Thorax, and fix inferior of the neck, and is inferted into the Os Occipitis, and back- part of the Os Temporis ; this laflpart isfome- times dillind: enough to be accounted another mufcle : It pulls the head and neck back. Rectus MajorPosticus, arifes from the fpinal procefTes of the fecond Vertebra of the neck, and is inferted broader into the Os Occipitis. It pulls the head back on the two flrfl Vertebra, I Rectus 114 Of the Mufcles. Rectus Minor Posticus, arifes from the back-part of the firfl Vertebra of the neck, (it having no fpinal procefs) and is inferted below the former into the fame bone to pull the head back on the Hrft Vertebra. Obliquus Superior, arifes from the tranfverfe procefs of the lirll Vertebra, and is inferted into the Os Occipitis and back-part of the Os Temporis near the Re6lus Major ; either of thefe adling, affill the Redus Lateralis on the fame fide; but both together, pull the head back. Obliqjius Inferior, arifes from the fpinal procefs of the fecond Vertebra of the neck, and is inferted into the tranfverfe pro- cefs of the firft. This, with its fellow, alter- nately a6ling, turn the head with the firft Vertebra in a rotatory manner on the fecond, whofe ProcefTus Dentatus is the Axis of this motion. Intersp INALES CoLLi, are three Of four pairof mufcles between the bifid procelTes of the cervical Vertebras, which they draw nearer each other when the neck is bent back- ward. LoNGUS Colli, arifes laterally from the bodies of the four fuperior Vertebra of the Thorax, and from the anterior part of the tranfverfe procefTes of the ^Yt inferior Verte- bras of the neck, arid is inferted into the fore- part Of the Mufcles. iij part of the iirlt and fecond Yertebrse of the neck, which it bends forward. Intertransversales CoLLi,are por- tions of fleih between the tranfverfe procefTes of the Vertebras of the neck, like the Interfpi- hales, but not fo diftind \ they draw thefe pro- cefTes together. Spinalis Colli, arifes from the tranf- verfe procefTes of the five fuperior Vertebras of the back , and is inferted into the fpinal procefTes of the fecond, third, fourth and fifth Vertebras of the neck. This pulls the neck backward. Transversalis Colli, arifes from the oblique procefTes of the four inferior Verte- brae of the neck, and is inferted into the fpi- nal procefs of the fecond Vertebra of the neck. This mufcle is but a continuation of the Tranf- verfalis or Semifpinalis Dorfi. The mufclesof the head and neck are mofl of them obliquely diredled, which rnakes them perform the oblique motions, as well as exten- fio^ and flexiori; which is highly convenient in this cafe, becaufe the joynts moved by thefe ^nufcles, being under the weight moved, it is necelTary that the head fhould be kept fleady by the extenfors, and flexors too, when any great weight is upon the head % and thefe mu- fcles from the obliquity of their directions, not only perform thefe two adlions at once, but ad- I 2 ing ii6 Of the Mujcles. ing by pairs they move the head and neck fteadily, in a diagonal dirediion, which ftraight mufcles could not have done fo well. Mufcles Scalenus arifes from the tranfverfe Tho^'ax p^ocefies of the fecond, third, fourth, fifth and fixth cervical Vertebra. It is inferted in three parts, ( being thus divided for the tranf- miffion of the fubclavian vefTels) into the two 'Uppermoft ribs. This mufcle may bend the neck, but its chief ufe is to fupport its upper ribs, which is neceifary to determine the con- tra6lion of the intercoftal mufcles that way, and a ligament could not have done this, becaufe of the various pofitions that the neck and back are liable to. Serratus Superior Posticus, ari- fes with a thin tendon infeparable from the Rhomboides, from the fpinal procefs of the in- ferior cervical Vertebra, and the three fuperior of the Thorax, and is inferted into the fecond, third, and fourth ribs, immediately beyond their bendings-, this, with the Scalenus, fuftains the upper ribs, that they might not be pull'd downward, by the depreifors of the ribs in expiration, as the lower ribs are upward in infpiration. SerratusInferiorPosticus, ari- fes with a broad tendon (infeparable from that of the LatilTimus Dorfi) from the fpinal pro- cefTes of the three fuperior Vertebrae of the loyns Of the Mufcles. 117 loyns, and two inferior of the Thorax, and is inierted into the tenth rib , but Ghiefiy the ninth and eleventh. It pulls down the ribs in exfpiration. Intercostales, are eleven pair on each fide, in the interflices of the ribs ; from their fi tuations diftinguifhed into external and internal ; they all arife from the under edge of each rib, and are inferted into the up- per edge of the rib below. The external are largefl backward, having their nrll beginnings from the tranfverfe proceifes of the Vertebrae like diftind: mufcles, which fome call Levato- res Coflarum. The internal run all from above obliquely backward ; being thickeft forwardg and thinneft toward the fpine. Thefe are alfo continued betwixt the cartilages of the Ster= num,with fibres perpendicular to the Cartilages; and between the cartilages of the loweft ribs, they are infeparable from the Obliquus Afcen- dens Abdominis. Thefe mufcles by drawing the ribs nearer to each other, pull them all up- ward, (they being fuftained at the top by the Scalenus and Serratus Superior Poilicus) and dilate the Thorax. To thefe Mr. Cowper adds fome flefhy fibres, which run from one rib over a fecond to a third, near the fpine. which are Levatores Coflarum. Triangularis Sterni, arifes inter- nally from the Cartilago Enfiformisj and the I 3 lower ii8 OftbeMufcles. lower edge of the Os Pedtoris, and is inferted into the end of the third, fourth, fifth and fixth ribs. This pulls the ribs to the bone of the Sternum, and thereby bends its cartilages in exfpiration. DiAPHRAGMA, arifes on the right fide by a procefs from three lumbal Vertebrae, and one of the Thorax j and on the left, from the one fuperior of the loyns, and inferior of the Thorax ; (this lafl part being lefs to give way to the great artery) and is inferted into the lower part of the Sternum and the ^Yt inferior ribs. The middle of this mufcle is a flat ten- don, from whence the flefhy fibres begin, and are diflributed, like Radii, from a center to a circumference. When this mufcle adis alone, it conilridrs the Thorax, and pulls the ribs downward , and approaches toward a plain ; which adion is generally performed to pro- mote the ejection of the Fsces. In large in- fpirations, when the intercoilals lift up the ribs to widen the Thorax, this mufcle ads enough to bring it felf toward a plain with- out overcoming the force of the intercoflals ; by which means the breafl is at once widened and lengthened : When it acts with the abdo- minal mufcles it draws the ribs nearer together, and conftridls the Thorax, and the fuperior force of the abdominal mufcles thrufling the parts of the lower bdly againft it, it becomes at Of the Mufcles. 119 at the fame time convex upward, and fhortens the Thorax, which occafions the largeft exfpira- tions; or afting alternately with the abdominal mufcles only, a more moderate infpiration and exfpiration is made by fhortening and length- ening the Thorax only, which is what we chiefly do when lying down ; or adiing alternately with ih^ intercoftals only, a moderate exfpiration and infpiration is caufed by the widening and narrowing the breaft, which is what we are moil prone to in an ere6l pofition, the mufcles of the Abdomen, at fuch times, being employ- ed in fupporting the parts contained in the Ab- domen, And though thefe motions of the ribs require at any one time but very little force, the air within the Thorax balancing that with- out ; yet that thefe mufcles whofe motions are eflential to life may be never weary, theinfpira- tors in mofl men have force fufficient to raife mercury in a tube four or five and twenty in- ches, in an ere6b pofture, and the exfpirators fix or feven *, the firft of which will require a- bout four thoufand pound force in mofl men, and the other proportional, But I imagine, that lying down, thefe proportions will differ by the weight of the parts contained in the Abdomen. In all the bodies I have diffedted, I have found the diaphragm convex upward, which gave me occafion to think, that all animals died in ex- fpiration, till the forexnentigned experiment I 4 dUcovered, I20 Of the Mufcles, difcovered, that the mufcles of infpiration were flronger than thofe of exfpiration ; which led me to make the following experiment. I cut the wind-pipe of a dog, and having a firing ready fixed, I put a cork into it, and tyed it fail inflantly after infpiration •, upon which I obferved, that the diaphragm, and the other mufcles of infpiration and exfpiration were alternately contraded, and diftended for fome time -, but when he was dead, the abdominal mufcles were in a flate of contradlion , the ribs were elevated to dilate the Thorax, and the diaphragm was convex upward ; this ex- periment alfo fhews, that the diaphragm is not a mufcle of equal force either to the deprefibrs or elevators of the ribs, it neither hindering the elevators froni raifmg tjie breall ; nor the deprefibrs from thrufling it upward, by com- prefling the parts contained in the Abdomen, though the bread was full of air. Mufcles SacerSacrolumbalis, Longissi- of the j^jus Dor SI, and Semispinali5, are all back'and ^^^^ portion of flefh betwixt the Os Sacrum peck. ^^(i the neck, which, feeing there is no mem- bran^ to diflinguilh it into feveral mufcles, and that it is all employed in the fame actions, I ihall give it the name of Ext en for Dorfi & Lumborum, and defcribe it all as one mufcle. Extensor Dorsi & LumboruMj arifes from the upper part of the Os Sacrun^, the Of the Mufcles. 121 the fpine of the Os Ilium, the back-parts of the lowermoil Vertebra of the loins, and remark- ably from thofe ftrong tendons which appear on their outfides. That part of this mufcle which is known by the name of Sacrolumbalis is inferted into all the ribs near their articula- tions, with the tranfverfe procelTes of the Ver» tebras, and into the tranfverfe procefs of the laft Vertebra of the neck j befides, as this pafles over the ribs, it receives an origin from eve- ry rib, in a manner that cannot well be defcrib^ ed: The portions of this mufcle which arife froni the ribs, and are inferted into other ribs above will necefTarily draw the back-part of the ribs nearer together , which muft always be done as the back extends, and independent of other a6lions of the Thorax. The nextporti- pn of this mufcle, called Longiffimus Dorfi^ is inferted into all the tranfverfe proceiTes of the Vertebras of the back, and partly into the ribs, and the uppermoft tranfverfe procefles of the Vertebras of the loins ; and the upper end of it is neither very diftind from the Complexus of the head, nor Spinalis of the neck. The reft of this mufcle, known by the names of Semi- fpinaHs, Sacer, &c. arifes alfofrom all the trar^f- yerfe and oblique procelTes of the loins and back-, every portion, except the lowermoft, pafTmg over five joints, is inferted into the ipinal procefs of the fixth Vertebra above its origin^ I z 2 Of the Mufcles. origin , all the way up the back, and at the neck commences Tranfverfalis Colli : This palling of each portion of a mufcle over a few joints, diilributes their force equally enough a-, mong all thefe joints, without the fibres being direded more obliquely than thofe of penni- form mufcles*, but the neck and loins not having fufficient provifion of this fort, there are fmall mufcles between their proceffes , which though they are of little importance for the motions of thofe parts, yet are fufficient to di- llribute the force of larger mufcles equally a- mong thofe joints j and befides the ufes of the Extenfor Dorfi & Lumborum, which its name implies, it, and its fellow, alternately raife the taps in walking, which any one may feel by laying his hand upon his back. Mufcles Q^ADRATUS LuMBORUM, arifes from of the the upper part of the fpine of the Ilium, and is inferted into all the tranfverfe procefTes of the four uppermoil lumbal Vertebras. This, with its fellow, ading alternately, affifl the lafl mentioned mufcle in railing the OfTa Innomina- ta in progreilion: Or each a6ling fmgly, while the lower limbs are not moved, inclines the body to one fide. IntertransversalesLumborum, are fmall mufcles feated between all the tranf- verfe procefTes of the Vertebras Lumborum, to bring them nearer together. Psoas loins. Of the Mufcles. 113 Psoas Parvus, arifes laterally from the body of the firll: lumbal Vertebra, and the lowell of the back, and foon becoming a fmall tendon, is inferted into the Os Pubis near the Ilium. It either allifts in bending the loins for- ward, or railing the Os Innominatum in progref- •five motions. This mufcle is often wanting. Psoas Magnus, arifes laterally from the ^ - bodies and tranfverfe procefies of the four fu- of the perior Vertebrse of the loins, and the laft of ^^^S^. the back, and is inferted with the following mufcle into the lefTer Trochanter. This bends the thigh, and when the Pfoas Parvus is want-r^ ing this is larger. IliacusInternus, arifes from the con- cave part of the Ilium , and from its lower edge, and pafling over the Ilium near the Os Pubis, joins the former mufcle, and is in- ferted with it, to be employed in the fame adion. P E c T I N E u s, arifes from the Os Pubis or Pedinis , near the joining of that bone with its fellow, and is inferted into the Linea Afpera . of the thigh-bone, four fingers breadth below the lefTer Trochanter. This bends the thigh and turns the toes outward. TricepsFemoris, the two lefTer heads of this mufcle arife under the Pedlineus , and the third from the inferior edges and back-part of the Os Pubis and Ifchium, and is inferted into. IZ4 Of the Mufcles. into the whole length of the Linea Afpera and the inner Apophylis of the Os Femoris. This alfo bends the thigh and turns the toes out- ward. When the thigh-bone is moved in a plain, which cuts at right angles a plain that pafTes through the Axis of either head of the laft mufcle, that head rifmg lower than the cen- ter of motion of the hip-joint, it will equally affift both the flexors and extenfors, and that mofb when the bone has been moved moft back- ward or forward ; and as either of thefe heads lie more or lefs out of the faid plain, they will give greater afliftance to that motion which is made on the fide of the faid plain, contrary to their Situation, and lefs on the fame flde. This mechanifm is frequently made ufe of to make one mufcle ferve different adlions ; but I have only explained it in this inftance, becaufe it is the moil confiderable one that I know. Gluteus Maximus, arifes from the back-part of the fpine of the Ilium, and the Dorfum Ilii, and fide of the Os Coccygis and Sacrum, and a ligament extended between thefe bones, and from a thin Fafcia fpread over that part of the following mufcle , which thi^ does not cover, and is inferted by a ftrong tendon into the upper part of the Linea Afpera of the thigh-bone, and alfo into the fiat tendon of the Fafcialis mufcle, which infertion into, or con- nexion with, that tendon raifes this mufcle far- Si ther Of the Mufcles, i x j ther from the center of motion and encreafes its ftrength. This extends the thigh, and both thefe together being contracted, occafionally alTift the Levatores Ani in fupporting the Anus. The breadth of the origin and infertion of this Mufcle, is very obfervable, for by that means, though it is the largeft mufcle in the body, it is neverthelefs right-lined without one fibre comprefling another any more than in penni- form mufcles. Gluteus Medius, arifes from all the anterior part of the Spina and Dorfum Ilii, and under part of the laft mentioned mufcle, and is inferted into the upper part of the great Tro- chanter of the thigh-bone. This extends the thigh outward. Gluteus Minimus, arifes entirely un- der the former, from the Dorfum Ilii, and is inferted into the upper and anterior part of the great Trochanter and neck of the thigh-bone to extend the thigh. Pyriformis, arifes internally from the infide of the Os Sacrum, and growing in more than half its progrefs into a round tendon, is inferted into the upper part of the finus at the root of the great Trochanter. This affifts fome- what in extending the thigh, but more in turn- ing it outward. Qu adratusFemoris, arifes from the obtufe procefs of the Ifchium, and is inferted into ii6 Of the Mufcles.' ' into the upper part of the Linea Alpera of the thigh-bone, between the two Trochanters. This draws the thigh inward, and diredts the toes outward; Obturator Internum, or Mar- suPiALis, arifes generally from a ftrong mem- brane or ligament, which fills up the hole of the Os Innominatum, and from the circumam- bient bone ; thence paffing over a chanel in the Ifchium betwixt its two procelTes, it re- ceives from them two other portions, which are a fort of Marfupium v and is inferted into the Sinus of the great Trochanter. This turns the thigh outward. Obturator ExTERNUs, arifes oppo- lite to the forrher, from the dutfide of the Os Innominatum, and is inferted into the Sinus of the great Trochanter. This alfo turns the thigh outward Thefe four laf^ mentioned mufcles a ariles acute from the upper part or the Tibia, and from the upper and middle part of the Fibula and ligament between thcfe bones; then Of- the iviufcles. I 3 then dividing into five tendons, four of them are infcrted into the fecond bone of each lelTer toe, and the fifth into the beginning of the me- tatarfalbone of the kail toe, and fometimes by a fmall tendon aifo into the little toe. This lail portion, for the mofb part is feparate, from its beginning, and may be accounted a diftind mufcle. The four firll tendons only of this mu- fcle extend the toes, but all five bend the Tar- fus, and that with a longer lever than any of them bend a toe. Extensor Digitorum Brevis, a- rifes together with the Extenfoi' Pollicis Brevis from the Os C^lcis, and dividing into three fmall tendons is inferted into the fecond joint the three toes next the great one. The long lextenfors of the toes ferve not only to extend them, but alfo contribute to the bending of the ancle, which motions are ufually performed together in progreffion ; but the Ihort exten- fors arifmg below the ancle, extend the toes only, and when the long extenfors are employ- ed for that adion only, the extenfors of the Tarfias mufl adb at the fame time, to prevent the bending of the ancle \ this is the reafon why the toes have need, though their motions are lefs, of more extenfors than the fingers. Flexor Brevis or Perforatus, ^rifes from the under and back-part of the Os Calcis y thence palTing toward the four leiTer K 4 toes. 136 ^ Oj the Mufcles. toes, divides into four tendons5which are infert- ed into the beginning of the fecondbone of each of the leiTer toes. Thefe tendons ^re divided to \tx, through the tendons of the following mufcle. Flexor Longus or Perforans, arifes from the back-part of the Tibia, above the in- fertion of the Popliteus, and part of the Fibula ; thence defcending under the Os Calcis to the bottom of the foot becomes tendinous, which part crofTes, and, in moft bodies, communi- cates with the Flexor Longus Pollicis Pedis ; then it divides into four tendons, which pafs through thofe of the Flexor Brevis are inferted into the third bone of each of the four leffer toes. This mufcle alfo extends the Tarfits. The fecond beginning of this mufcle arifes from the Os Calcis , and joins the tendons where they divide. This portion only bends the toes*, and feeing the Flexor Longus of the toes will, when it a6ls alone, extend the Tarfus as well as bend the toes, this portion (like the fhort extenfors of the toes) feems purpofely contrived to bend the toes alone. LuMBRiCALES, atifc from the tendons of the Perforans, and are inferted int6 the firfl bone of each of the lefTer toes, which they bend. Abductor MiNiivii Digiti Pedis, arifes by the Perforatus from the Os Calcis, ijtid being part of it inferted into the metacar- pal Of the ujcies. 137 pal bone of the leaft toe, it receives another beginning from the Os Cuboides, and is inferr- ed into the firfb bone of the leaft toe, which it bends and pulls outward, and very much helps to conftrid the bottom of the foot. Abductor Secundus Minimi Dj- (Gi Ti, this arifes under the former rnufcle from the metatarfal bonp, and is inferted into the little toe. I N T E R o ss E I, are feyen mufcles v/hich li^ Jike thofe of the hands, and arife like them from the metatarfal bones, and are inferted lilce them into the laft joints of the four leJfTer toes, and being in their progrefs attached to the tendons which extend the fecond joints of the toes, they will extend both thefe joints. Thefe mufcles may be fitly divided into external and internal, the internal alfo bend the iirft joints, as do all the Interoffei in the hand, but here the outer ones extend the firft joints j and if we ponfider that the firft of thefe mufcles is anala- gous to the Abdudor Indicis of the hand, and that the Abdudor Minimi is alike in both, we find that the mufcles to move the fingers and lefler toes fideways are alike in number, though this motion of the toes is in a manner loft from the ufe of ftioes. The mufcles that bend or •extend the laft joints of the toes will alfo move the fecond and firft, and thofe that move the fecond will alfo move the firft. The fame re- ^ mark 138 Of the Mufcles. mark iliouid have been made about the mu- fcles of the fingers. Though a great many authors have thought it worth while to contend in many inflances which Ihall be called the origin, and which the infertion of fome mufcles, whofe ends have been both liable to be moved, yet none of them have confidered, that every extenfor of the thigh. Tibia, and Tarfus, has always had that end which is moft moved called its origin, and the other its infertion i contrary to the rule which all have laid down to judge by. The number of the mufcles cannot be ad- jufted, becaufe anatomifts are neither agreed about fome of them, whether they fhould be counted mufcles or not, nor of others how far they fhall be divided j though in the main, they fecm to think him the beft anatomift who di- vides them moil ♦, for my own part, I am not for dividing them as far as they can be divided, but as far as is neceffary to the knowledge of their ufes« TABLE C^/Z^. i1>^ i/.7^^l/ucAjrJ^> i 139 TABLE XI. Figure I. A redlilineal mufcle. Fig. 2. A fingle penniform mufcle. Fig. 3. A double penniform mufcle. Fig. 4. Is a fcheme to explain the different pro- perties of redilineal and penniform mu- fcles. AB, are |:wopulli^s, about which the chord CDEFG is infledbed. H I, are two equal weights, hung in a perpendicular diredipn at each end of this chord. K, is another weight hung at E, the middle of that part of the chord whichlies between the pullies. When the weight K, and the weights li I balance each other, the coline of half the angle D E F, bears the fame proportion to the Radius, as the weight K bears to the fum of the weights Handl: So that the weight K, muft never be fo great as the fum of the weights H I •, and the lefs the weight K is, the greater will be the angle D E F, when the weights are in Equilibrio. Befides, if the weight K be raifed diredtly up- wards, the velocity wherewith the weight K is made to afcend, will be to the velocity wherewith each of the weights H I will defcend, as the Radius to ihQ cofme of half the angle D E F, TABLE 140 TABLE XII. 1. Frontalis. 2. Maftoideus. 3. Goracohyoxdeus. 4. Sternohyoideus. 5. A fmall part of the Trapezius, 6. Deitoides, 7. Pedtoralis. 8. Part of the Serratus Major Antki^. 9. Obliquus Defcendens Abdominis. 10. The portions of the Rie^ti, the left being di veiled of its Fafda. J I, Pyramidales. iz. Biceps Cubiti Flexor. 13. Braeheus Flexor. 14. Triceps Extenfor Cubit.L 15. 16. Supinator Radii Lpngus. 17. Flexor Carpi Radialis. 1 8. Flexor Carpi Ulnaris. 19. The firft head of the Extenfor Carpi Ra^ dialis. ao. The fecond head of the fame mufcle. 21. Extenfor Digitoxum Coijimunis. 22. Fafcialis or Membranofus. 23. Sartorius. 24. One head of the Triceps. 2.jf. Pedineus. 26, The great head of the Triceps. 27, Gra- ij ^-^ Jtrcnm ddia: Jiiitort J\']cko[Ij sciil£ 141 27. 2 8. 29. 31- 32. 33* 34. 35- Gracilis. Redlus. Vaflus ExternuSi Vaflus Internus. Semitendinofus. Gafterocnemeus Externus* Soleus, or Gafterocnemeus Internus^ Tibialis Anticus. Tenfor Pollicis Pedis Longus* TABLE 142. Table xiil Mufcles of the face, • A, Frontalis. B, Temporalis. C, Maffeter. I), Orbicularis. E, Sphin6ler Oris. F, Elevator Labii Superioris Proprius. G, Elevator Labiorum Communis. H, DeprefTor Labiorum Communis^ I, DeprefTor Labii Inferioris PropriuSo K, Zygomaticus. L, Buccinator. M, l^he right iywith its mufclesi ' . N, Obliquus Superior. O, The Trochlea through which it paflTes^ P, Obliquus Inferior. Q, Elevator Occuli. R, DeprefTor Occuli. S, Addudtor Occuli. T, Abdudtor OccdL U, The optick nerve* /f vieiJiJ fez^.^^a, M3 Avtew ofthepojlerior external mufcles. 1. Maftoideus. 2. Trapezius. 3 . A very fmall part of the Elevator Scapulas. 4. A very fmall part of the Rhomboides. 5. Deltoides. (5. LatifTimus Dorli. 7. Teres Major. 8. Infrafpinalis Scapula. 9. Triceps extenfor Cubiti. 10, Anconeus. J I. Extenfor Carpi Ulnaris. 1 2. Extenfor Carpi Radialis. f^, Extenfor Digitorum Communis. 14. Extenfor Primi Internodii Pollicis. 15. A very fmall part of the Supinator Radii Longus. 16. Gluteus Maximus. 17. Gluteus Medius. 18. Membranofus or Fafcialis. 19. Gracilis. 20. The great head of the Triceps. 21. Semimembranofus. 22. Semitendinofas. 23. Biceps Tibis. 24. Vaftus Externus. 25. Gafterocnemeus Externus. 26. Soleus, or Gafterocnemeus Internus, I. BOOK o •■ 145 BOOK III. CHAP. L Of the external parts^ and common integuments. THE vulgar names of the external parts of the human body being fufficiently known for the defcription of any dif- eafe or operation j I fhall only deferibe thofe which anatomifls have given for the better un- derftanding of the fub-contained parts. The hollow on the middle of the Thorax^ under the breafts, is called Scrobiculus Cordis. The middle of the Abdomen for about three fingers breadth above and below the navel, is called Regio Umbilicalis. The middle part above this, Epigaftrium. On each fide of the Epigaftrium, under the cartilages of the lower ribs, Hypochondrium j and from below the Re-' gio Umbilicalis down to the Oflallia, and.Of- fa Pubis, Hypogailrium. CUTI- 1^6 Of the external parts ^ &c. CuTicuLA or Scar F-S KIN, is that thin infenfible membrane which is raifed by bli- flers in living bodies : It is extended over every part of the true fkin, iinlefs where the nails are. It appears to me in a microfcope a very fine fmooth membrane, only unequal where the Re- ticulum Mucofum adheres to it. Lewenhoeck and others, fay, it appears fcaly, and compute that a grain of fand of the hundredth part of an inch diameter, wiJl cover two hundred and fifty of thefefcales, and that each fcale has about five hundred pores -, fo that according to them, a grain of fand will cover 125000 pores,through which we perfpire. Its ufe is to defend the true fkin that it may not be expofed to pain from whatever it touches ; and alfo to preferve it &om wearing : It is thickeft on thofe parts of the bottom of the foot which fuftain the body ; and in hands much ufed to labour, being fo contrived as to grow the thicker, the more thofe parts are ufed. Between this and the true fkin, is a fmall quantity of llimy matter, which was fuppofed, byMalpighi, and others, to be contained in pro- per veffels, interwoven with one another, and therefore by them named Reticulum Muco- fum. It is moft confiderable where the Cuti- cula is thickeft, and is black, white, or dufky, Tuch as is the complexion ; the colour of this, and the Cuticula, being the only difference be- tween Of the externalparts^ &c. 147 tween Europeans, and Africans or Indians, the fibres of the true Ikin being white in all men \ but the florid colour of the cheeks, is owing to the blood in the minute veflels of the fkin, ag that in the lips to the veflels in the mufcular fleftii for the Cuticula (as I imagine) being made of excrementitious matter, has no blood veflels. Cutis or True Skin, is a very corn- pad, fl:rong, and fenflble membrane extended over all the other parts of the body, having nerves terminating fo plentifully in all its fu- perficies, for the fenfe of touching, that the finefl: pointed inflirument can prick no where without touching fome of them. Thefe nerves are faid by Malpighi, and others, who have examined them carefully, to terminate in fmall pyramidal Papilla j neverthelefs to me it feems, that a plain fuperficies of the flcin ( I do not mean mathematicafly plain) is much fitter and more agreeable to what we experience of this fenfation-, for a plain fuperficies expofing all the nerves alike, I think would give a more equal fenfation, while nerves ending in a pyra- midal Papilla would be exceeding fenflble at the Vertex of that Papilla ; and thofe at the fides and round the bafe, which would be far the greatefl: part, would be the leafl: ufefuL Glandule Miliars s, are fmall bo- dies like millet feeds, feated immediately under L 2 the Of the external parts ^ 8cc. the Ikin in the Axilla's ; and are faid to have been found under all other parts of the fkin, where they have been looked for with micro- fcopes : Thefe glands are fuppofed to feparate fweat ; which fluid was formerly thought to be only the Materia Perfpirabilis flowing in a great- er quantity, and condenfed; but Sanctorius has affured us, that it is not fo, and that more of the Materia Perfpirabilis is feparated in equal times than of fweat ; of the former, he fays, ufually fifty two ounces a day in Italy, where his experiments were made, and of the latter not near fo much in the moll profufe fweats ; which, I think, favours the opinion of the ex- iilence of thefe glands, unlefs the fweat be- ing once condenfed upon the fkin, prevents a greater effufion of that matter. Now that the whole body, every part of which is furely per- fpirable ( or how elfe could extravafated blood or matter ever be difTipated, unlefs it could be abforbed into the veffels, which feems impofli- ble, feeing that the fluids which are in motion in the veflTels mufl out-balance thofe which are extravafated ) fhould perfpire fifty two ounces in a natural day, is not at all incredible. But that thefe glands, if there are fuch under all the H^in, fhould be able to make fo large fecretions appear not very probable to me, however I wilh thofe who have more leifure and judgment than my felf, would examine this more nicely^ becaufe Of the external parts^ &c. 149 becaufe fo much theory of cutaneous difeales depends upon it. Membrana Adiposa, is aJl that mem- brane immediately under the flcin, which con- tains the fat in cells •, it is thickeft on the Ab- domen and buttocks, and thinnefl neareft the extremities j and where the mufcles adhere to the fkin, and on the Penis, none. It con- tributes to keep the inner parts warm, and by filling the interftices of the mufcles, renders the furface of the body fmooth and beautiful, and may perhaps ferve to lubricate their furfaces, and whether the decreafe of fat which often follows- labour or ficknefs, proceeds from its being reafTumed into the blood veflels, or whe- ther it is conftantly perfpiring through the fkin, and the leiTening of its quantity is from the want of a fupply equal to its confumption, is with me a matter of doubt, though the former opinion I know generally prevails. Mammae, the Breasts, feem to be of the fame ftrudture in both fexes, but largeft in women. Each breaft is a conglomerate gland to feparate milk, feated in the Membrana A- dipofa, with its excretory duds, (which are capable of very great diftention,) tending to- ward the nipple, which as they approach, they unite, and make but a, fev/ duds at their exit. There are to be met with in authors, infliances fufficiently attefted of mens giving fuck, when L 3 thej I J o Of the Membranes tn general. they have been excited by a vehement defire of doing it : And it is a common obfervation, that milk will flow out of the breafts of new- born children, both male and female. . ^ _ ^ CHAP, IL Of the Membranes in general. EVe RY dillin<5l part of the body is covered, and every cavity is lined with a fmgle membrane, whofe thicknefs and llrength is as the bulk of the part it belongs to, and as the fri6lion to which it is naturally expofed. Those membranes that contain diftin£t parts, keep the parts they contain together, and render their furfaces fmooth, and lefs fub- je6l to be lacerated by the adions of the body. And thofe which line cavities, ferve to render the cavities fmooth, and fit for the parts they contain to move againfl. The mernbranes of all the cavities that contain folid parts, are fludded with glands, or are provided with veflels, which feparate a Mucus to make the parts contained move glibly againft one another, and not grow together. And thofe cavities which are expofed to the |iir, as the nofe, ears, mouth, and Trachea Arteria, have their membranes befet with glands Of the falwary Glands. i j i glands, which feparate matter to defend them from the outer air. Thofe membranes that have proper names, and deferve a particular defcription, will be treated of in their proper places. _ J ^ CHAP. III. Of the faUvary Glands. PArotis orMAXiLLARis Superior, is the largeil of the falivary glands ; it is fituate behind the lower jaw, under the ear ; its excretory dud pafTes over the upper part of the MafTeter mufcle, and enters the mouth through the Buccinator. This gland has its Saliva promoted by the motions of the lower jaw. Its du6l pafles over the tendinous part of the MafTeter mufcle that it may not be com- prefTed by that mufcle, which would obflrudl the Saliva in it, though it is frequently faid that it pafies over that mufcle that it may be comprefTed by it to promote the Saliva, In Iheep and calves, their jaws being long, this mufcle is inferted far from the center of mo- tion, that the end of the jaw may be moved with fufficient ilrength, and that diftant infer- tion requiring a greater length of mufcle, that its motion may be quick enough, no part of L 4 this I J 2 Of the falwary Glands. this mufcle could be allowed to be tendinous, therefore it feems, to avoid the incohvenience of comprefTion from the mufcle, the dudt in thofe animals goes quite round the lower end of it. When this du6l is divided by an exter- nal wound, the Saliva will flow out on the cheek, unlefs a convenient perforation be made into the mouth, and then the external wound may be healed. I have feen two patients with this gland ulcerated, from which there was a conftant efFufion of Saliva, 'till the greateft part df the gland was confumed with red iT|er- cury precipitate^ and then it healed with little trouble. Hildanus mentions the fame cafe, which for two years had been under the care of a furgeon without fuccefs ; and was at lafl; cured by the application of an adual cautery. Maxillaris Inferior, is fituate be- tween the lower jaw, and the tendon of the digaftrick mufcle; its du(^ pafles under the Mufculus Mylohyoideus, and enters the mouth under the tongue, near the Dentes Inciforii. I was at the opening of a woman who was fuf- focated by a tumour which begun in this gland •, it extended it felf from the Sternum to the pa- rotid gland on one fide in fix weeks time, and in nine weeks killed her. It was a true Schir- rus, and weighed twenty fix ounces. In a man which I difleded, I found a quantity of Pus Ofthefalwary Glands. 153 Pus near this gland, and a bundle of matter not unlike hair as large as an hen's egg. Sublingualis, is a fmall gland fituated under the tongue, between the jaw and the Ceratagloflus mufcle. In a calf I found feve- ral dudis of this gland filled by an injedlion into the dud of the fubmaxillary gland; but Mor- gagni and others affirm that the du6ls of this gland enter the mouth diredly from the gland in feveral places near the grinding teeth. T o N s I L L A, is a globular gland about the bignefs of a hazel-nut, fituate upon the Ptery- goideus Internus mufcle, between the root of the tongue and the Uvula. It has no dud con- tinued from it, but empties all its fmall duds into a Sinus of its own, which Sinus, when the gland is inflamed, may eafily be miftaken for an ulcer. This gland with its fellow, dired the mafticated aliment into the Pharynx; and alfo ferve for the Uvula to fliut down upon when we breathe through the nofe. They are com- preffed by the tongue and the aliment, when the former raifes the latter over its root, and thereby opportunely emit their Saliva to lubri- cate the food for its eafier defcent through the Pharynx. A fchirrous tumour of either of thefe glands is a common difeafe, and it ad- mits of no remedy but extirpation ; yet it muft not be performed upon the whole gland, butfo much of it as is become iupernaturally eminent; becaufe 54 Of the falivary Glands. becaufe that would be dangerous as well as dif- ficult. The beft way of extirpating thefe glands , is, I think, by ligature : if the gland is fmall at its bafis, the ligature may be tied round it, which I have eafily performed by fixing the liga- ture to the end of a probe, which I bent, and fo drew it round the gland, and tied it ; about five days after this ligature growing loofe, I put on another in the fame manner, and then in a few days the gland dropped off^: But meeting with another cafe of this kind, where the bafis of the gland was too large to tie , I contrived an Inftrument like a crooked needle fet in a handle with an eye near the point ; I thruftthis inftrument, with a ligature in it through the bottom of the gland, and then taking hold of the ligature with a hook, I drew back the in- ftrument; then drawing the double ligature forwards, I divided it, and tied one part above and the other below, in the fame manner that I did to extirpate part of the Omentum in the cure of an Hernia : See the plate at the latter end of this book, and this fucceeded as well as the former. I once faw them totally deftroy- ed by venereal ulcers, and the Uvula, which was whole, having nothing to fhut againft, the patient fnuffled almoft as much as if the Uvula had been gone. Pressure upon the furface of a gland very much promoting the fecretion that is made Of the fai'wary Glands, 1 5 y made in it, thefe glands are fo feated as to be prefled by the lower jaw, and its mufcles, which will be chiefly at the time when their fluid is wanted ; and the force with which the jaw muft be moved, being as the drinefs and hardnefs of the food maflicated, the fecretion from the glands depending very much upon that force; it will alfo be in proportion to the drinefs and hardnefs of that food which is necelTary -, for all food, being to be reduced to a pulp, by being mixed with Saliva before it can be fwallowed fit for digeftion, the drier and harder foods needing more of this matter, will from this mechanifm be fupplied with more than moifter foods in about that proportion in which they are drier and harder , and the drier foods need- ing more Saliva than moifler, is the reafon why we can eat lefs and digeftlefs of thefe thanthofe. What quantity of Saliva thefe glands can fepa- rate from the blood, in a given time, will be hard to determine, but in eating of dry bread it can- not be lefs than the weight of bread ; and ma- ny men, in a little time, can eat more dry bread than twice the fize of all thefe glands ; and fome men, that are not ufed to fmoaking, can fpit half a pint in the fmoaking one pipe of tobacco i and fome men in a falivation, have fpit, for days or weeks together, a gallon in four and twenty hours ; and, yet I believe, all thefe glands put together, do not weigh more than four ounces. The I J (5 Of the falwary Glands. The membrane which lines the mouth and palate, and covers the tongue, is every where befet with fmall glands, to afford Saliva in all parts of the mouth to keep it moift -, for thofe more remote are chiefly concerned in time of maflication. Thefe fmall glands have names given them according to their refpedlive fitua- tions, as Buccales, Labiales, Linguales, Fauci- ales, Palatini, Gingivarum, and Uvulares. A GLAND is chiefly compofed of a con- volution of one or more arteries of a confiderable length, from whofe fides arife vaft numbers of ex- cretory duds, as the ladeals arife from the guts, and for the fame reafon; for the paffages into the excretory duds of a gland, being fuch as that only one fort of fluid may pafs into them, the want of largenefs is compenfated by their num- ber; and in a great length of an artery, as in the guts thofe^^roper fluids which efcape one duct may pafs into another ; and from what has been faid, it does not appear but that ex- cretory duds may arife from the velfels that form membranes without being convolved at all. And this way I imagine fecretions are made from all the membranes that line cavities, and fome others. There alfo arife from thefe ar- teries lymphatic veffels, whofe ufe feems to be to take off the thinnefl part of the blood, where a thick fluid is to be fecreted, feeing they are found in greatell plenty in fuch glands as fejiarate. Of the fahvary Glands. 157 feparate the thickeil fluids, as in the teflicles and liver; and it is obfervable that where the thickefl fecretions are made, the velocity of the blood is the leaft, as if it was contrived to give thofe feemingly more tenacious parts more time to feparate from the blood. The arte- ries that compofe different glands are convol- ved in different manners, but whether or no their different fecretions depend upon that, I doubt will be difficult to difcover. The excre- tory du6ls arife from the arteries, and unite in their progrefs as the roots of trees do from the earth, and as different trees, plants, fruits, and even different minerals, in their growing, often derive their dillind proper juices from the fame kind of earth j fo the excretory dudls in different glands, feparate from the fame blood their different juices: But what thefe different fecretions depend upon, whether the ftrucbure of the parts or different attradions, are what we have no certainty about, though this fub- jed has employed feveral of the befl writers.. For my own part, from the great fimplicity and uniformity ufually feen in nature's works, I am moil inclined to think different fecretions arife from different attradlions, feeing that in plants and minerals there feems to be no other way. CHAP. IJ8 nr CHAP. IV. Of the Peritoneum^ Omentum ^ DuSius Alimentalts and Mefentery. PERITONEUM, is a membrane which lines the whole cavity of the Abomen. It con- tains the liver, fpleen, omentum, flomach, guts and mefentery, with all their veiTels and glands ', the upper part of it is no other than the proper membrane of the diaphragm, and, but for compliance with cuilom, there is no more reafon for calling that, part of the Peri- toneum, than there is for calling the membrane on the other fide of the diaphragm part of the Pleura or Mediaftinum. The fore part next the mufcles of the Abdomen, and their tendons maybe divided into two Laminae, yet I think anatomifts in defcribing the duplicature or La- minae of the Peritoneum have not always meant this divifion, but have taken the tendons of the tranfverfe mufcles for the outer Lamina, and coniidered the other as one membrane, feeing that it is between thefe tendons and the Peri- toneum that the water is ufually found in that kind of dropfy which is called the dropfy in the duplicature of the Peritoneum. Upon the loins the inner furface only is fmooth, and the 6 outer Of the Peritoneum^ Omentum^ &c. 159 outer part a fort of loofe Membrana Adipofa, in which are contained the Aorta, Vena Cava, Vafa Spermatica, and Pancreas, with other parts of lefs note. The middle of the Peritone- um upon the loins is joined to the mefentery in fuch a manner, as makes fome account it a produdion of the Peritoneum, and fome part of the external membrane of the Duodenum, becoming one membrane with the inner or fmooth Lamina of the Peritoneum, and part of the Redlum is covered in the fame manner ; but the kidneys and bladder of urine are con- tained in a diftindl duplicature of this mem- brane. The dropfy of the Peritoneum, may be diflinguiflied, by being leaft prominent a- bout the navel, for there the tendons and the Peritoneum will not feparate ; and the water, in thofe that I have diiTeded , had made the parts where it was contain'd as foul as any ul- cer; therefore none of them I prefume could have been cured by operation. For the Umbilical vefTels, fee chap, of the Foetus. For the Proceflus Vaginalis, chap, of the parts of generation in men. Om e n t u m, or C aw l, is a fine membrane larded with fat, fomewhat like net-v/ork: It is fituated on the furface of the fmall guts, and re- fembles an apron tuckM up ; its outer or up- per part, named Ala Superior, is conneded to the 1 6o Oj the Omentum. the bottom of theftomach, thefpleen, and part of the Inteflinum Duodenum ; and thence de- fcending a little lov/er than the navel, is refledl- ed and tyed to the Inteftinum Colon, the fpleen, and part of the Duodenum : This laft part is called Ala Inferior 5 and the fpace between the Als is named Burfa. This cavity is very diftind in moil brutes, but feldom fo in men. Sometimes both Al^ are tied to the liver, and, in difeafed bodies, to the Peritoneum. Its ufe is, to lubricate the guts, that they may the better perform their periftaltick motion. Mal- pighi defcribes adipofe duds in this membrane to carry the fat from the cells into the Vena Portarum, and thinks it a neceffary ingredient in the bile. In dropiies of the Abdomen, and in perfons who from any other caufe have died tabid, it is generally rotten and decayed ; and fometimes the guts in thefe cafes adhere to one another: But whether thefe adhefions proceed from the Omentum's ceafing to perform its of- fice, or from the periftaltick motion of the guts, being long difcontinued through abftinence, or both, I cannot determine. I have feen pne in- ftance, from diifedion, of a very large rupture of the Omentum, or Epiploon, into the groin, together v/ith one of the guts ; the rupture of the Omentum, is called by authors Epi- plocele. 6 Ductus Of the DuBus AltmentaUs, i6i Ductus Alimen talis, is the CEfo- phagus, ftomach and guts, viz. Duodenum, Je- junum, Ileum, Colon, Csecum or Apendicula Vermiformis, and Redum. ^ CEsopHAGUS or gullet, is the begin- ning of the alimentary du6i: -, its upper part is wide and open fpread behind the tongue to receive the mafticated aliment; it begins from the bafis of the fcull near the Froceflus Ptery- goides of the Iphenoidal bone, then defcending becomes round, and is called Vaginalis Guls ; it runs from the tongue clofe to the fpine, un- der the left Subclavian blood vefiels, into and through the Thorax on the left fide, then pier- cing the diaphragm, it immediately enters the ftomach. It is compofed of a thin outer coat, which is no more than a proper membrane to the middle or mufcular coat. The middle coat is compofed of longitudinal and circular muf- cular fibres, but chiefly circular, abundantly • thicker than the fame coat in the guts *, becaufe this has no foreign power to alTiil it, as the guts have, and becaufe it is neccffary the food Ihould make a fhorter ftay here than there. The inner coat, is a pretty fmooth membrane, befet with many glands, which fecrete a mucilaginous matter, to defend this membrane, and render the defcent of the aliment eafy. Ventriculus, the ftomach, is fiCuat- ,p> . . . cd under the left fide of the diaphragm, its 6, M left 1 6 2 Of the Ductus Ahmentalis. left fide touching the fpleen, and its right is covered by the thin edge of the liver \ its figure nearly refembles the pouch of a bag-pipe, its left end being moll capacious, the upper fide concave and the lower convex •, it has two ori- fices, both on its upper part; the left (through which the aliment pafTes into the llomach) is named Cardia; and the right (through which it / is conveyed out of the ilomach into the Duo- denum) is named Pylorus ; where there is a cir- cular valve which hinders a return of aliment out of the gut, but does not wholly hinder the- gall from flowing into the ftomach. The coats of the flomach are but threes the external membranous, the middle mufcular, whofe fibres are chiefly longitudinal and circu- lar, the inner membranous , and befet widi glands, which feparate a Mucus. This lail coat is again divided by anatomiils into a fourth, .which they call Villofa. As the mufcular coat of the flomach contrads, the inner coat falls into folds, which increafeas the flomach lefTens, and confequendy retard the aliment mofl when the fbomach is neareft being empty. The manner in which digeflion is perform- ed has been matter of great controverfy. The ancients generally fuppofed the food concodl. ed by a fermentation in the flomach: But the moderns more generally attribute it to the muf- cular force of the flomach ; which Dr. Pitcairne has Of the DuBus Akmental'ts. 163 has computed to be equal to a hundred and fe- venteen thoufand and eighty eight pound weight," to which being added the abfolute force of the diaphragm and abdominal mufcles ; (but for what reafon T am at a lofs to conceive, when fo fmall a part of that force can be exerted this way) the fum then will be. more than twice as much; a force indeed equal to the end for which he affigns it. Now this force of the muf- cular coat of the llomach is near forty times greater than what Borelli has affigned to the heart, which is much ftronger ; and Dr. Keil has undertook to prove, that the force which the heart exerts is not thrice as many ounces as ; Borelli computes it to be thoufand pounds weight. And this is as certain as that adi- on and reaction are the fame; that the abdo- minal mufcles and the diaphragm, comprefs the ftomach v/ith no greater force than they dd the liver and all other parts contained in the Abdomen •, and that the Foetus in Utero, and all theVifcera in the Abdomen, receive much more of this force, during the time of geilation ; and yet neither the F(rtus, nor any other contain- ed part, is digefted by that force ; and for the force with v/hich the; ilomach it felf ad:s, it will be juft the fame with the reaftion of the food upon it, anql therefore Hiould be as much more liable to be digefted by this and the other force than the food, as it oftner feels thefe forces M 2 than 164 Of the Ducius AUmentalis. than that, (only that living bodies are not fo liable to digeftion as dead ones) : Befides, I think it may be demonilrated, that the force with which the flomach comprefTes any part of its contents, is not greater than what is given to equal parts of the contents in the fmall guts *, for if the moment of a mufcle is as its weight, and if the mufcular coat of the ilomach does not bear a greater proportion to the mufcular coat of a fmall gut, than their diameters bear ; * a fedlion of the fcomach, having fo many more equal parts to prefs than a like feciiian of a gut ; k will require juft fo much more force to give . each part the fame prefTure. Dr. Drake has fuppofed, that digeftion is performed in the flomach, as in Papin's digefter, in which hy- pothefis are contained all the abfurdities of that of Pitcairne's, Vv^ith this addition, that the fto- mach muft be as irrefiftible to diftention at that time, as his iron pot, and the orifices as forci- bly fecured ; but then indeed it fhews how bits of bones, wi'iich dogs fwallow may be retained in the ftomach without tearing it ; which dif- ficulty, in my opinion, Dr. Picairne has not fuf- ficiently accounted for, though it is none of the leafi in his hypothefis. In granivorous birds, where digeftion is made by mufcular force, their fecond ftomach is plainly contrived for com- minuting or digefting their food that way ; for befides that it is one of the ftrongeft mufcles in I their Of the DtiBus Aliment alts. 165 their bodies, its infide is defended with a hard and {Irong membrane that it may not be torn ; and thefe birds always eat with their grain the roughed and hardeft little flones they can find, which are neceflary for grinding their food, notwithitanding it is firft foaked in another ftomach, and is alfo food of very eafie digefli- on. In fnakes, fom.e birds, and feveral kinds of fifh. which fwallow whole animals, and re- tain them long in their flomachs, digeflion feems to be performed by a Menflruum ; for we frequently find in their flomachs animals fo totally digefled, before their form is deflroy- ed, that their very bones are made fofc. In horfes and oxen, digeflion is but little more than extrading a tin(Sl:ure j for in their excre- ments, when voided, we fee the texture of their food is not totally deflroyed, though grafs in particular feems to be of as eafy di- geflion as any food whatever , and the corn they eat is often voided entire ; and in the ex- crements of men, are often feen the fldns of fruits un digefled, and fmall fruits, fuch as currants, unbroke , and v/orms alfo continue unhurt, both in the flomach and guts. There- fore by comparing our flomachs with thofe here mentioned, it appears to me that our di- . geflion is performed by a Menflruum which is chiefly Saliva, afTifled by the adion of the ilor mach, and the abdominal mufcles, and by that M 3 principle i66 Of the Ductus Alimentaits. of corruption which is in all dead bodies* Fordigeflion is no other than corruption of our food, and therefore quantities of hot fpirits, which hinder the corruption of animal bodies, alfo hinder digefi:ion. Duodenum, is the firfl of the three fmall guts \ it begins from the Pylorus of the fto- mach, and is thence reflected downward j it firfl paiTes by the gall-bladder, and then un- der the following gut and mefentery, and com- ing in fight again in the left Hypochondrium, it there commences Jejunum, which is the fe- cond of the fmall guts \ but the place where this ends and the other begins, is not precifely determined. Tab. xiy. J e J u N u M, is fo called from its being found ' ' for the mofl part empty j it is fituated in the Regio Umbilicalis, and makes fomcwhat more than a third part of the fmall guts. It is di- ilinguiflied from the following gut by its coats, which are a fmall matter thinner, and \t{% pale. ab. siv. Ileum, is the continuation of the former, fituated in the Hypogaftrium, and very often fome part of it in the Pelvis of the Abdomen, upon the bladder of urine ; efpecially in wo- men, it enters the Colon on the right fide, near the upper edge of the Os Ilium, This great length of the fmall guts is evidently for phe convenience^ of a greater number of ladeals Of the DuBus Altmentalts. 167 ladeals, that the chyle which milTes their ori- fices in one place may not efcape them in ano- ther. But thofe animals which fwallow their food whole, and have it a long time in their ftomachs and guts, have fhorter guts and few- er ladeals. Colon, is the firil of the great guts; it begins at the upper edge of the right Os Ilium ; thence afcending pafles under fome part of the liver, and the bottom of the ilomach, from the right Hypochondrium to the left, and thence defcends to the Pelvis Abdominis, C^cuM, or Apendicula Yermiform.is, is fituated on the beginning of the Colon , it is lefs than an earth-worm, with a fmall orifice opening into the Colon. This gut has feldoni any thing in it. In men it is called one of the large guts, though it is the fmallefl by far ; but the miftake arifes from copying the anci- ents, v/hofe defcriptions of all the parts con- tained in the Abdomen feem to be taken from dogs, for in them and in many other ani- mals, it is very large: And fome fifh have them in great numbers, but very fmall, I have counted in a mackarell above 150. Rectum, is the continuation of the Colon through the Pelvis to the Anus. The guts have the fame coats with the ftomach ; the fibres of their middle or mufcu- lar coat, are circular, or fpiral, and longitu-^ M 4 dinal;. 1 6 8 Of the DuBus Aliment alts. dinal, of the latter but very few. The anta- gonifts to thefe mufcular fibres of the llomach and guts, are their contents prefTed from one place to another, and the mufcles of the Ab- domen, for thefe preffing upon them alter their form into one lefs capacious; which necefia- rily extends their circular fibres. The great guts have three membranes, or ligaments, on the outfide running their whole lengths, and fupporting the Saculi, into which thofe guts are divided. The lefTer guts, have at very fmall diftances femilunar valves placed oppo- fite to the interftices of each other; they pre- vent the aliment from pafiing too fpeedily through the guts ; and the better to anfwer that end, they are larger and more numerous near the ilomach, where the food is thinner, than they are towards the Colon, where the food is continually made thicker in its progrefs, by a difcharge of part of the chyle. But brutes have them not, becaufe they are not necefiary to an horizontal pofcure. At the entrance of the Ileum into the Colon, are two very large valves, which efiedually hinder the regrefs of the Foeces into the Ileum. But clyflers have been frequently known to pafs them, and be vomited up; but the excrement that is fome- times vomited up, I am inclined to think, is fuch as had not paffed into the great guts: The other valves in the Colon, are placed op- pofite Of the DuBus Aliment alts. 1 69 pofite (but not in the lame plane) to each other, and make with their anterior edges an equi- lateral triangle ; but as the gut approaches the Anus, they become lefs remarkable, and fewer in number. All the guts have in their inner membrane an almoft infinite number of very fmall glands : Thefe glands will, fome of them efpecially in the large guts appear to the naked eye when they are difeafed: They are called Glandulae Pyerian^. The length of the guts to that of the body is as five to one in a middle-fized man ; in taller men, the proportion is ufually lefs, and in ihort men greater. The following cafe I had thus related (in prefence of a great many gentlemen who had feen the cafe) from Mr. Punt of Cambridge, a gentleman, when living, well known for his great fkill in Surgery. " I WAS called to a poor woman, a few ^' years fmce with a mortification upon the . " Abdomen. I cut away the mortified part, ^' and found fome of the fmall guts mortified. *' I cut off fo much of them as could not be ^' faved, and ftitched the found part of the " gut, to a found part of the wpund, near the t' navel •, to which it afterward adhered, and ' ' fhe recovered and voided her excrement that \' way, without any notable inconvenience; " and 1 7 o ' Of the Ducius Altmentalts. "^ and at every flool part of the gut would *' thruft out, without any pain, like a Prolap- ^' fus Ani: But about a year after the cure, ihe *« died of the Hone. " I do not remember that he told me what caufed this mortification, but my honoured friend Martin Folks, Efq; who lets nothing curious fcape his obfervation, and was at that time of Clare-Hall in Cambridge, has informed me, " That the mortification <' was made by laying hot bricks to her belly, *' for the choHck, fome, of which burnt her, *' and when the flough call off a gut appearing^ '' a female furgeon took it for a blifter and clip- *' ed it, upon which the excrement came out " of the wound, and then they fent for Mr. *' Punt. The following cafe, was of a patient to Mr. Walter , a Surgeon , at Lewis in SufTex^^ whom I have heard relate it ; but for this ac- count as well as the cut, I am obliged to my ingenious friend Dr. RulTel, who faw the cafe ; but I cannot be of Mr. Walter's opinion, that it was the Colon tha^ was mortified, SIR, *' "X yfl^s. Stoneflreet, of Levv^is in Sulfex, XVJL '^^ had the Exomphalos above twenty . ^' years, before it was attended with the fol- ^' lowing accident. In the year i^oo, the *' twenty eighth of May, ihe was taken with I ^*^ a cholick^ OftheDuBus Altmentalts. 171 *' a cholick, and a total fupprellion of ftools ; *' the inteftine mortified , and part of it was '' taken off by Mr. Walter, a Surgeon, who " gave me an account of the cafe, and allured " me it was the Colon ; the other part was " thruil out daily by the periftakick motion of ^' the guts, when the excrements were voided, " till it adhered to the wound; and had the *' jull appearance of v/hat is expreiTed in the *' pidure I fent you. I had a perfect exami- * ' nation of it in her life-time, but no oppor- " tunity of opening her after death ; the fides *' of the inteftine firmly adhered to the belly, " and the part which hung out, looked like a " pale fcarlet ftrawberry, that had not its full ^' ripenefs •, and the coats of it were extremely ^' thickened. She lived in this condition twelve " years, and died of a fever, with fcorbutick 5' fwellings in her legs. I am Sir, &c. Richard Russel„ Ttxii following cafe happened in my own pradice: Margaret White, the wife of John '^^^*^^^'^' White, a penfioner in the fiHimongers alms- houfes, at Newington in Surry, in the fiftieth year of her age had a rupture at her navel, which continued till her feventy third year, when after a fit of the cholick it mortified, and Ihe 172. Of the DuBus Ahmentalts. being prefently after taken with a vomiting, it burfl. I went to her and found her in this condition, with about fix and twenty inches and an half of the gut hanging out mortified. I took away what was mortified, and left the €nd of the found gut hanging out at the navel, to which it afterwards adhered, and Ihe reco- vered. It is now three years fince this accident happened, and ihe continues perfedlly well, voiding the excrements through the Inteftine at the navel, and though the ulcer was fo large / after the mortification feparated,that the breadth of two guts was {^tvi \ yet they never at any time protruded out at the wound, though fhe was taken out of her bed and fat up every day. But for a cafe nothing inferior to any of thefe, I am obliged to a farrier, or do6lor for cattle, as he flyles himfelf : The truth of this cafe is known to numbers of perfons ; as Mr. Hunt, a gentleman of unqueftionable veracity has informed me, before whom the following account was given upon oath. , ^'^ ^TpHoMAS Bravn of Yeaton, in the X '' parifh of Bafchurch, and county of " Salop, a dod:or for cattle, maketh oath, *' that about ten or twelve years agone, he *^' was fent for by a farmer or hufbandman, who '' lived near the village called Maefbrooks, "and very near to the river Verney, in the faid ^' county Of the Duclus Altmentalts. 17^ *' county of Salop, to have his advice about " an ox he had, which was there fick by reafon " he could not dung; he had been drenched " by feveral beaft-do6lors , before this depo- " nentcame to him. This deponent feeing tnis " ox in the condition he was in, told the own- ^^ er, that if he would venture his ox, he would " do him what fervice he could, in the curing '' of him ; which the owner confented to, and " thereupon this deponent opened the ox in *' the flank, and took out great part of his " bowels, upon fearching of which he found ^' there was aperfedftoppage in the guts ; and " the gut was about the floppage putrified " for about three quarters of a yard, where- " upon this deponent cut off fo much of the " gut as was putrified, and took it quite away, *' and then drew the ends of the guts which " remained found after what v/as cut off, to- " gether upon a hollow keck, which was about *-'- three or four inches long, and fewed the " faid ends of the guts together upon the faid " keck, leaving the keck within the guts; and " then fewed up the hole cut in the hide upon " the flank of the faid ox ; and this deponent *' further faith, that within the fpace of one *^ hour after this operation was performed, " the ox dunged ; and the piece of the keck ^' which the faid ends of the gut were fewn " upon and left within the guts, came away '^ from 174 ^f ^^^ Me/entery. *-' from the ox with the dung, whereupon the " ox recovered and lived to do the ov/ner *' fervice feveral years. Jurat, decimo feptimo The mark of diejulii, annoDom. =z: 1715. coram Thomas Brayn; Tho. Hunt. Mesentery, is a membrane beginning loofely upon the loins, and is thence produced to all the guts : It preferves the Jejunum and Ileum from twilling in their periilaltick or ver- micular motion, and confines the reft to their places. It fuftains all the veffels going to and from the guts, viz. arteries, veins, lymphse- du6ts, ladeals and nerves, and alfo contains many glands,, called from their fituation Mefen- tericse. The beginning of this mem.brane from' the loins, is about three or four inches broad, but next the guts of the fame length, with the fide of the guts they adhere to, which is in the fmall guts about a fourth part Ihorter than the other fide ; but when this membrane is fepa- rated from the fmall guts, it Ihrinks, and mea^ fures about two thirds lefs. T OPENED a boy about twelve years old, that died of the iliac pafTion-, the guts, fto- mach. Duodenum and Jejunum were diftend- ed, with vapour and air, to near ten times their natural Of the Mefentery. 17 j_ natural capacity, which fo compreffed the Inteftinum Ileum, that nothing could pafs throuo-h it. The relations of this boy could give no other account of the caufe of this dif- eafe, than that of his having eaten a large quan- tity of raw young carriots. This cafe happens very frequently to lambs that have been houf- ed, and turned out early in the fpring to grafs, when the grafs is very rank and fucculent ; and alfo to horfes, oxen and Iheep, when they hap= pen to feed by any accident, upon young beans or peas, or rich clover grafs, which are full of air, and very apt to ferment and ex- pand in their ftomachs : In thefe animals this cafe is commonly cured by running a knife in- to their guts, fome inilances of which I have feen, and have heard a great many reported ; but this cafe happening very rarely to men, and being to be cured fometimes by the fwal- lowing of crude mercury, I believe that prac- cice has never yet been ufed ; though the in- ftrument which is ufed for tapping in a drop- fie of the Abdomen, would do it with great eafe and fafety. Some anatomifts, who have confidered the impoflibility of a twilling of the guts, (which is the vulgar name of this dif- eafe) have imagined that it proceeded from one gut being involved in another, but thefe involutions, are found in mofi bodies that die a natural xy6 Of the liver ^ gall-bladder ^ Sec. a natural death, and without any inflammation. or any other fymptom of pain. CHAP. V. Of the liver y galU bladder ^ pancreas and fpleen. Tab.xiv. '""T^He Liver, IS the largefl: gland in the XV. 4. , Jl body, of a dufky red colour. It is fituated immediately under the diaphragm in the right Hypochondrium ; its exterior fide is convex, t and interior concave *, backward toward the ribs it is thick, and thin on its forepart, where it covers the upper fide of the itomach, and fome of the guts ; the upper fide of it adheres to the diaphragm, and is alfo tyed to it and the Sternum by a thin ligament, which is de- fcribed commonly as two ; the upper part call-- ed Sufpenforium, and the anterior Latum; but either of thefe names is fufRcient for it all : It is alfo tied to the navel by a round ligament called Teres or Umbilicale, which is the um- bilical vein degenerated into a ligament *, it is inferted into the liver at a fmall iifTure in its lower edge. The Ligamentum Latum or Suf- penforium, fuflains the liver in an ered poflure, or rather fixes it in its fituation, while it is fup- ' ported Of the Itver and gall-bladder. 177 ported by the other Vifcera, they being com- preffed by the abdominal mufelesj in lying down, the Teres prevents it from preffing on the diaphragm ; and in lying on the back, they both together fufpend it, that it may not com- prefs and obftru6l] the afcending Vena Cava. I fuppofe it is nourifhed by the branches of the celiac and mefenteric arteries in the liver cal- led Arterias Hepatic2e, but its blood-vefTels, that compofe it as a gland, are the branches of the" Vena Porta?, which enters the liver, and di- ftributes its blood like an artery, to have the bile fe ere ted from it (Vid. Vena Ports) and y^jj^rj,.^ the branches of the Cava in the liver, which re- turn the redundant blood into the Cava Afcen- dens ; it has alfo feveral branches of nerves, and Tab. xx. a great number of lymphaticks : Of which 17>8. fhall treat in their refpedlive places. Dogs and cats and other animals, that have a great deal of motion in their backs, have their Hvers di- vided into many diftincl: lobules ; which by moving one upon another, comply with thofe motions, which elfe would break their livers to pieces. The gall-bladder, is a receptacle of bile, Tab. xt; featedin the hollow-fide of the liverj it is com- '3- ^x.3; pofed of one denfe coat fomewhat mufcular, which is covered with a membrane like that of the liver ; and is alfo lined with another, that cannot eafily be feparated. N MoDERiqt 1/8 Of the Itver and gall blader. Modern anatomifts have defcribed a num- ber of fmall duds leading from the liver to the gall-bladder, by which they fuppofe the gall- bladder is filled, and thefe I thought I had feen in a human body that died of a jaundice, when I was a very young anatomift; but never be- ing able to fee any fmce in any animal, though I have made very diligent enquiry by experi- ments and difiedtion, I begin now to be per- fuaded that there are no fuch duds ; for if they are too little to be feen or filled by injedions, I think they are much too little for the end for which they are affigned. As to the argument for the exiilence of fuch duds, which is fetched from the difficulty of the gall-bladder's being filled through the Dudus Cyfticus from the . Dudus Hepaticus, I think it is of no weight, becaufe the Veficulse Seminales, we know are filled with a thicker fluid through a \t{^ dircd pafiage. From the gall-bladder towards the Tab.xx.4. -P^,®^^^^^' runs a dud called Cyfticus ; and Tab XX i.froTn the liver to this dud, one called Hepa- ticus, which carries off the gall this way, when Tab.xx.5. ^^^ S^^^~^^^^^^^' ^^ full; then the dudus Cyfti- cus and Hepaticus being united, commence Dudus Communis Choledochus, which enters the Duodenum obliquely about four inches be- low its beginning. The orifice of this dud in the gut is fomewhat eminent, but has no caruncle, as is commonly faid. As the liver from Of the Pancreas and fpleen, 179 from its fituation in the fame cavity with the flomach, will be moll prefTed and confequent- ly feparate mod gall when the llomach is ful- ieft, which is the time when it is moll wanted ; fo the gall-bladder, being feated againil the Duodenum, will have its fluid prefled out by the aliment pafiing through that gut, and confequently at a right time, and in due pro- portion ; becaufe the greater that quantity of aliment is, the greater will be the compreflion ; and fo the contrary. Pancreas, the fweet-bread, is a large Tab.xv.6. gland of the falivary kind, lying a-crofs the upper and back-part of ^the Abdomen, near the Duodenum ; it is what the antients called a conglomerate gland, appearing fo without dif- fedion to the naked eye \ it has a fhort excreto- ry dud, about half as large as a crow-quill, though it is commonly painted as large as the Dudus Communis Choiedochus: It always en- ters the Duodenum together with the bile du6t ; but in dogs fome diilance from it; and, I think, always in two duds diftant from one another. The juice of this gland, together with the bile, ferves to complete the digeilion of the ali-. ment, and render it fit to enter the lacleal veffels. The fpleen, is feated in the left Hypo- '^^^^ .^^^ chondrium, immediately under the diaphragm, 0» and above the kidney^ between the llomach N 2 and i8o Of the fpleen. and the ribs ; it is fupported by the fub-con- tained parts, and fixed to its place by an ad- hefion to the Peritoneum and diaphragm ; it is alfo connefbed to the Omentum, as has been obferved. The figure of it is a fort of depreffed oval, near twice as long as broad, and alrnoft twice as broad as thick: Sometimes it is divid- ed into lobules, but for the moft part, has only one or two fmall fifTures on its edge, and fome- times nonci in its colour it refembles cafl-iron. The inner texture in brutes is veficular, like the Penis ; in which veficles are found grumous blood, and fmall bodies, like glands: But Ruyfch denies that the human fpleen is of the fame texture. I KNOW no way of computing with any exadnefs, the quantity of bile that is ufually fecreted by the liver in a given time; but if it is four times as much as all the falivary glands fecrete, it may be twenty four ounces for every meal ; to which being added fix ounces of Saliva, which, from what I have ob- ferved in the chapter of the falivary glands, I think will appear a moderate computation. And fuppofing the Pancreas in the fame time fecretes three ounces, there will then be thirty three ounces of fluids feparated for the digefti- on of one meal -, and that thefe neceflary fluids may not be wafl:ed in fuch quantities, they pafs into the blood with the chyle, and may be foon I feparated Of the fpleen. 1 8 i feparated again for the fame ufe •, and very likely, fome of the fame bile may be employ- ed more than once, for digefting part of the fame meal : And as the liver exceeds all the glands in the body in magnitude, and its ex- cretory dudts ending in the Duodenum, it feems to me to be much more capable of making thofe large feparations from the blood, v/hich are procured by catharticks, than the fcarce vifi- ble glands of the guts. The liver, ordinarily weighs, in a mid- dle-fized man, about three pounds twelve ounces, the Pancreas three ounces, and the fpleen fourteen ounces. The fpleen I have taken out of a dog, without any remarkable inconvenience to him. And I have twice, in a humane body, feen three fpleens, tv/ice two, and once four ; fome of thefe were very fmall, others nearly equal, but all togther in any of thefe bodies, were not greater than the one which is ufually found. I have feen a difeafed liver in a man, that weighed fourteen pounds four ounces *, and in a boy but nine years old, that died hydropick, I found the liver full of hydatids, and cylls of hydatids adhering to it, which together weighed feven pounds, one ounce and a half, though feveral pints of water had been let out of it before. The fpleen, in the fame boy, together with the hydatids con- tained in its membrane, weighed three pounds i N ^ In 1 8 2 Of the Vafa LaHea. In a man I found a difeafed fpleen , weighing five pounds two ounces; and in an old man fix foot high, I found a found liver, weighing no more than twenty eight ounces, and the fpleen but ten ounces : And in a man that was cured of a dropfy, I found a Polypus very fohd, almoil filling the large branches of the Porta in the liver, and a llone betwen the liver and gall-bladder, larger than a nutmeg \ and in a man that died of a jaundice, I found the Dudlus Communis Choledocus, conftridled by a fcir- rhous Pancreas , the gall-bladder extended to the fi7:e of a goofe-egg, and all the dudts to twice their natural bignefs. This is the cafe in which I thought I had fo plainly feen the cyftyhepatick dudls; I once faw the Du6tus Cyllicus obfl:ru6ted without the gall-bladder, being diflended fo much as is ufual, which, I think, furnilhes us with a very probable argu-= ment againft the exiilence of cyftyhepatick duels. CHAP. VI. Of the Vafa LaBea, VAsA Lactea, are the Venas Ladeas, Receptaculum Chyli^ and Dudlus Tho- r^cicMS,. 1 ' VeN23^ Of the Vafa LaBea, 183 '. Ven-£ Lacte^, &c. are a vafi: number of very fine pellucid rubes, beginning from the fmall guts, and proceeding thence through the mefentery ; they frequently unite, and form fewer and larger veffels, which firft pafs through the mefenterick glands, and then into the Re- ceptaculum Chyli: Thefe veffels e'er they ar- rive at the mefenterick glands, (or in dogs the Pancreas AiTellii, which is thefe glands colled:- ed) are called Vense Ladiese Primi Generis \ and thence to their entrance into the Receptacu- lum Chyli, Ven^ Lades Secundi Generis. The office of thefe veins, is to receive the fluid part of the digefted aliment, v/hich is called chyle, and convey it to the Receptaculum Chyli, that it may be thence carryed through the Duc=- tus Thoracicus into the blood-velTels. For the following excellent defcription (thus marked'') of the Receptaculum Chyli, and Duc- tus Thoracicus, lam obliged to Mr, Monro. " Receptaculum Chyli, Pecquet!, " or Saccus Ladieus, Van Home, is a mem- " branous fomewhat pyriform bag, two thirds *^ of an inch long, one third of an inch over in *' its largeft part, when collapfed j fituated *' on the firft Vertebra Lumborum, to the '' right of the Aorta, a little higher than the *' Arteria Emulgens Dextra, under the right *' inferior mufcleof the diaphragm \ it is form-*. f e4 by the union of three tubes, one from un- N 4 '- 4^r 184 Of the Vaja LaBea. *■' der the Aorta, the fecond from the inter- " ilice of the Aorta and Cava, the third from *' under the emulgents of the right fide. The " Saccus Chyliferus at its fuperior part becom- *' ing gradually fmaller is contraded .into a " flender membranous pipe of about a line " diameter, well known by the name of "Ductus Tkoracicus, this pafTes *' betwixt the Appendices Mufculofae Dia- '^ phragmatis, on the right of, and fomewhat *' behind the Aorta, then lodged in the cel- '' lular fubflance under the Pleura, it mounts " between this artery and Vena Sine Pari, or " Azygos, as far as the fifth Vertebra Tho- *' racis, where it is hid by the Azygos, as this " vein rifes forward to join the Cava Defcenr *' dens, after which the dud: pafTes obliquely " over to the left fide under the CEfophagus, *' Aorta Defcendens, and great curvature of *' the Aorta, until it reaches the left earotide, " flretching farther towards the left internal *' jugular, by a circular turn, whofe convex *' part is upmofl- j at the top of this arch it " fplits into two for one half line, the fupe- " rior branch receiving into it a large lym- *' phatick from the cervical glands. This lym- " phatick appears by blowing and injedlions " to have no valves ; when the two branches *' are united, the dud: continues its courfe to " the internal jugular, behind which it de- " fcends. Of the Vafa LaBea. 185 '' fcends, and immediately at the left fide of *' the infertion of this vein, enters the fuperi- '•^ or and pofterior part of the left fubclavian, " whofe internal membrane duplicated forms " a femilunar externally convex valve that " covers two thirds of the orifice of the dud:; " immediately below this orifice a cervical vein ^' from the Mufculi Scaleni enters the fubcla- " vian. The thin coat and valves, commonly '> ten or twelve, of this dudl are fo generally " known, I need not mention them. In my '* notes I find little variation in theRecepta- ^' culum, only its different capacities in ditfe- " rent fubjecls, and fometimes more duds '' concurring in the formation of it. "The diameter of the dud varies in moft " bodies, and in the fame fubje6l is uniform, " but frequently fudden enlargements or Sac- " culi of it are obfervable. The divifions ^' which authors mention of this dud within " the Thorax are very uncertain: In a woman " I diffeded lafl fummer, at the eighth Verte- " bra Thoracis, one branch climbed over the " Aorta, and about the fifth Vertebra flipped " back again under that arterie to the other " branch, which continued in the ordinary " courfe. Lail winter I found this dud of a " man difcharging it felf entirely into the right " fubclavian vein. The i86 Of the J/gfa LaBea. "The pre cife Vertebra where it begins to ^' turn towards the left is alfo uncertain. Fre- *' quently it does not fplit at its fuperior arch, '' in which cafe a large Saccus is found near *' its aperture into the fubclavian vein. *' Generally it has but one orifice, f' though I have feen two in one body, and f ^ three in another \ nay, fometimes it divides *' into two under the curvature of the great '' artery, one goes to the right, another to the *' left fubclavian; this however is very rare. *' The lymphatick, which enters the fuperi- '' or arch, is often fent from the thyroide gland. Supposing there ordinarily pafTes five pounds of chyle in a day through the ladleals, and that four ounces of this only is added to the blood, (though it may be any other quan- tity for ought I know) and that a man neither decreafes nor encreafes during this time, then all the feparations from the fluids and fohds mufl be juft five pounds ; four, ounces of which muft be thofe fluids and particles of folids, which are become unprofitable \ and the re- maining four pounds tv.^elve ounces, will ferve. as a vehicle to carry the four ounces off: So that we fee for what reafon more fluids are car- ried into the blood than are to be retained there, and how the body is by the fame means both nourilhed and preferyed in health. The Of the Pleura^ &c. 187 The chyle is diluted in its pafTage by the lymph. Vid. chap, of the Lympaticks. CHAP. VII. Of the Pleura^ Mediaji'mum^ Lungs ^ Perkardrnm^ and Heart. PL EUR A is a fine membrane which lines the whole cavity of the Thorax, except on the diaphragm, which is covered with no other than its own proper membrane; the back part of it is extended over the great vefiels, like the Peritoneum ; and in regard this mem- brane pafies partly under thefe vefTels, as the Peritoneum does in the Abdomen, they may be faid to lie in a duplicature of it ; it ferves to make the infide of the Thorax fmooth aM equal. Mediastinum, (if we may defcribe fuch a membrane in the humane body) divides the Thorax lengthways, from the Sternum to the Pericardium and Pleura, which is a very fliorc fpace, but in many brutes very confiderable. It divides into two in men, but in brutes it is fmgle \ it divides the Thorax not exadlly in the middle, but towards the left fide, and is fo difpofed, that the two cavities, into which jt divides the Thorax, do not end toward this membrane % 1 8 8 Of the lungs. membrane in an angle, but a fegment of a cir- cle \ it hinders one lobe of the lungs from in- commoding the other, as in lying on one fide the uppermoft would frequently do *, and pre- vents the diforders of one lobe of the lungs from affeding the other. Tab.xiv. Ti|e lungs, are compofed of two lobes, one feated oii each fide of the Mediaftinum, each of which lobes are fub-divided into two or three Ipbules, which are moil diftindly di- vided in fuch animals as haye rrioil motion in their backs, for the feme end that the liver is in the fame animals \ they are each compofed of very fmall cellsg which are the extremities ' of the Afpera Arteria or Bronchos. The figure of thefe cells is irregular \ yet they are fitted to each other, fo as to haye common fides, and leave no void fpace. Dr. Willis has given a very particular defcription oj the inner texture of the lungs , but it is wholly imaginary anci falfe, as he, and they who haye copied his cuts and defcriptions could not but have known, if they had ever made the leaft encjuiry into the lungs of any animal ; nor is his account of the lymphaticks on the furface of the lungs, at all more true than that of their texture. In the. membranes of thefe cells are diftributed the branches of the pulmonary artery and vein. The known ufes of the air's entering the lungs, are to be inflrumental in fpeech, and to coavey, Effluvia Of the lungs, 189 Effluvia into the nofe, as it paflfes, for the fenfe of fmelling j but the great ufe of it by which life is preferved, I thinic, we do not under- fland. By fome the force of the air is thought to feparate the Globuli of the blood, that have cohered in the flow circulation through the veins-, and this opinion feems to be favoured by the many inflances of PolypulTes (which are large concretions of the Globuh of the blood) found in the veins near the heart, and in the right auricle and ventricle of the heart, and their being fo feldom found in the pulmo- nary veins, or in the left auricle or ventricle of the heart, or in any of the arteries ; but if it is true that, while the blood pafTes through the lungs, many cohering Globuli are feparated, yet it remains to be proved that thefe fepa- rations are made by the force of the air. Dr. Keil has computed the force of the air in the ftrongeit expirations againft the fides of all the veficles, to be equal to fifty thoufand pound weight, yet if we confider we fhall ilill find the moment of the air in the lungs exceeding fmall in any fmall fpace. For the velocity with which the air moves in the lungs, is as much lefs than that with which it moves in the wind- pipe, as the fquare of a fe6lion of the cells in. the lungs is greater than the fquare of a fe6lion of the wind-pipe ^ and therefore if the fquare of all the extreme blood-veflels in the lungs, do ipo Of the lungs. do not bear a greater proportion to the fquare of the large pulmonary veflels than the fquare of the cells do to the wind-pipe , and if the blood in thefe large veiTels moves as fafc as the air in the wind-pipe ; (all which I think may be granted) then the blood moving in the fmallelt vefTels of the lungs with a velocity equal to that of the air in the cells^ the blood will have as much more prefTure from the power that moves it in its own veflels than the air can give upon them, as blood is heavier than air. Befides, air preffing equally to all fides , and the Glo» buli of the blood fwimming in a fluid; this preflTure, be it what it will , I think , can be of little ufe to make fuch feparations. Indeed it may be objedled that the greatelt preflure is in expiration, yet that furely cannot be much greater, while the air has fo free a paflage out of them. Others have thought that the air en- ters the blood- veflfels from the cells in the lungs, and mixes with the blood; but this opinion^ however probable, wants fuflicient experiments to prove it; air being found in the blood, as there certainly is, is no proof of its entering this way, becaufe it may enter with the chyle : Nor is the impoflibility which has been urged of its entering at the lungs without the blood bemg liable to come out the fame way into the vef- ficles of the lungs, a good argument to the con- trary ; for if a pliable dud paflfes between the membranes Of the kings. i^i membranes of a veffel, through a fpace great- er than the fqiiare of its orifice, no fluid can • return, becaufe the preiTure which iliould force it back will be greater againfl the fides of that du6l than its orifice s which is the cafe of the bile du6l entering the Duodenum, and the ure- ters entering the bladder. I think tHe bell arguments for the air's entering into the blood by the lungs, or rather fome particular part of the air, may be fetched from what the learned Dr. Halley, and others have obferved of a man's wanting in a diving bell, near a gallon of frefh air in a minute, for if nothing but preiTure had been wanted from the air in the lungs, there may be thrice as much preiTure without any fupply of frefh air, as upon the furface of the earth ; and animals dying fo foon in air that has been burnt, and their being fo eafily intoxi- cated by breathing air much impregnated with fpirituous liquors, are alfo, in my opinion, ar^ • guments of a paiTage this v/ay into the blood: Befides, if preiTure of the air in the cells of the lungs is the only ufe of it, I do not fee but e- nough of that may be had while a man is hang» ing, if the mufcles of the Thorax do Lut ad upon the air which was left in the Thorax when the rope was firil fixed, and yet death is brought about by hanging no other way than by interrupting of the breath, as I have found by certain experiments. Dr. Drake has endea- ^ vouixd I pi Of the Pericardium. • voured to fhew, that the ufe of refpiration is to affift the Syilole of the heart •, but this, ufe requires that the Syllole and Diaflole of the heart, fhould keep time with expiration and irifpiration, which is contrary to experience: Befides,. if his hypothefis was true, it could on- ly ferve the right ventricle of the heart. The lungs of animals before they have been dilfited with air, are fpecifically heavier than water, but upon inflation they become fpecifically lighter and fwim in water-, which experiment may be made to difcover whether a dead child, was Hill born or not ; but if the child has breathed but a little, and the experiment is made long- after, the lungs may be collapfed, and grow heavier than water, as I have experimented^ which may lead a man to give a. wrong judg^ ment in a court of judicature ; but then it will be on the charitable fide of the queftion* • Adhesions of the lungs to the Pleura are fo common, I know not how to call it a difeafe 5 they being found fo more or lefs in moil adult perfons, and witliout any inconvenience, if the lungs are not rotten. Tab xiv. PERICARDIUM or heart-purfe, is an ex- 1. ceeding flrong membrane which covers the heart j its fide next the great veffels is pardy connedied to them, and partly to the bafis of the heart; but, I think, not properly perfo- rated by thofe veiTels, and its lower fide is in- feparable Oj the heart. ip3 reparable from the tendinous part of the dia- phragm, but not fo in brutes, in fome of which there is a membranous bag between it and the diaphragni, which contains a lobule of the lungs. It enclofes all the heart to its bafis ; its ufes are to keep the heart in its place, without * interrupting its office, to keep it from having any fridlion with the lungs, arid to contain a li- quor to lubricate the furface of the heart, and abate its fridion againll the Pericardium. The heart is a mufcle of a conick figure, with two cavities or ventricles ^ its balls is fix- ed by the velTels going to and from it, upon the fourth and fifth Vertebras of the Thorax, its Apex, or point is inclined downward and to the left fide , where it is received in a ca- vity of the left lobe of the lungs, as may be obferved, the lungs being extended with air: This incumbrance on the left lobe of the lungs, I imagine, is the caufe of that fide's being maoft fubjed to thofe pains which are ufually called pleuritic, which, I think, are for the moft part inflammations in the lungs. At the bafis of the heart, on each fide, are fituated the two auricles to receive the blood; the right from the two cava's, and the left from the pulmonary-veins : In the right, at the meet- ing of the cava's, is an eminence called Tuber* culum Loweri, which diredls the blood into the auricle j immediately below this tubercle, in O the ip4 Of the heart. the ending of the Cava Afcendens, is the Vefti- • gium of the Foramen Ovale; (Vid. chap, of the Foetus) and near this, in the auricle, is the mouth of the coronary-veins. The left auri- cle is abundantly lefs than the right; but the . difference is fupplied by a large mufcular cavi- ty, which the veins from the lungs afford in that place ; the fides of this mufcular cavity are thick- er than the fides of the right auricle, in about that proportion in which the left ventricle of the heart is llronger than the right ; their ufes being to receive blood from the veins that lead to the heart, and prefs it into the ventri- cles ; a ftrength in each auricle proportionable to, the ftrength of the ventricle that it is to fill with blood, feems neceflary: And this diffe- rent thicknefs of the coats of the auricles makes the blood in the left, which is thickeft, appear through it of a paler red ; but when it is let out of the auricles it appears alike from both ; which they would do well to examine, who af- firm the blood returns from the lungs of a more fiorid colour than it went in; and offer it as, an argument, of the blood's being mixed with air in the lungs: In both auricles are mufcular; Columns, like thofe in the ventricles, but? fmaller. The ventricles or cavities in the heart which receive; the blood, are hollow mufcles, or two^ canities ii>. one^ mufcle, whofe fibres interfed one Of the heart. 195 one another, fo as to make the prelTure of the heart upon the blood more efFedual, and are alfo lefs liable to be feparated than they would have been if they had lain parallel ; both thefe cavities receiving the fame quantities of blood in the fame times, and always adling together, muft be equal in fize if they equally difcharge what they contain at every Syftole, as I doubt not but they do ; never thelefs the left appears lefs than the right, it being found empty in dead bodies, and the right ufually full of blood, which made the antients think the veins and the right ventricle only, were for the blood to move in, and that the left and the arteries con- tained only animal fpirits ; the left ventricle is much the thickell and flrongeft, its office be- ing to drive the blood through the whole body, while the right propels it through the luiigs only. Over the entrance of the auricles in each ventricle, are placed valves to hinder a return of blood while the heart contrad:s. Thofe in the right ventricle are named Tricufpides, thofe in the left Mitrales. One of thefe lafl feem to do further fervice, by covering the mouth of the Aorta while the ventricle fills •, which fuf- fering none of the blood to pafs out of this ven- tricle into the Aorta before the ventricle ads, it will be able to give greater force to the blood than it otherwife might have donej becaufe a greater quantity of blood more fully diftend- O 2 ing 1^6 Of the heart. ing the ventricle^ and making the greater re- fiftance, it will be capable of receiving the greater irnpreffed force from the ventricle, and if the blood is no way hindered in the right ventricle from getting into the pulmonary ar- tery, while the ventricle dilates as it is in the left, the left then muft be fomewhat bigger than the right, if they both empty themfelves alike in every Syftole : Though the auricles of the heart are equal to each other , and the two ventricles alfo equal, or nearly equal, yet the auricles are not fo large as the ventricles ; for the ventricles contain not only all the blood which flowed from the veins into the auricles, during the contraction of the heart, but alfo that which flows (which will be diredlly in- . to the heart) while the auricles contra6t, and the ventricles dilate •, which leads us to the ex- a6l knowledge of the ufe of the auricles. If the Syllole and Diaftole of the heart are per- formed in equal times, then the auricles muii: be half the fize of the ventricles; or whatever proportion the fpace of time of the Syflole of the heart, bears to the fpace of time in which thy Syflole and Diaflole are both performed, that proportion will the cavities of the auricles bear to the cavities of the ventricles. The inner fibres of each ventricle are dif- pofed into fmall cords, which are called Co- lumnse: From fome of thefe fland fmall por- / -3 tions Of the heart. 197 tions of flefh called Papillse ; thefe Papilla are tied to the valves by flender fibres^ whereby they keep the valves from being prelTed into the auricles, by the adtion of the blood againil them in the Syftole of the heart, and when that is,:over, the blood flowing in between them opens them, as the prefTure of blood on the other fide fhut them in the Syflole. (For the courfe of the blood through this part, Vid. chap, of the courfe of the aliment and fluids.) In the beginning of each artery from the heart are placed three valves, which look for- ward, and clofe together to hinder a regrefs of blood into the ventricles. Thofe in the pulmonary-artery 5 are named Sigmoidales, thofe in the Aorta, Semilunares, Canalis Ar- teriofus. (Vid, chap, of the Foetus.) In a boy I found a great quantity of Pus in the Pericardium, and the bafls of the heart ulcerated. In perfons that have died of a drop- fle, I have ufually obferved the heart large, its fibres lax, and the veflfels about it immoderately difliended, and polypufies fometimes in both auricles and ventricles, and in the large veins ^ but more frequently in the right auricle and ventricle. I difle6led a man that died tabids in whom the Pericardium univerfally adhered to the heart, and a portion of the mufcular part of the heart was oflified as large as a fix- Tab.ix.A, pence. The beginning of the Aorta, has been O 3 frequendv I p 8 Of the arteries and veins. frequently feen ofTified, efpecially in aged per- fons. In a woman that died of a dropfie , I found the valves of the Aorta quite cover- ed with chalk ftones, which not fuffering the valves to do their office, the left ventricle of the heart was conftantly overcharged with blood, and diftendedto above twice its natural bignefs, which I imagine deftroyed the oeconomy of the body, and occafioned the dropfie. CHAP. VIIL Of the arteries and veins. FR o M the right ventricle of the heart arifes the pulmonary artery, which foon divides into two branches, one to each lobe of the lungs, and then they fub-divide into fmaller and fmaller branches, until they are diftributed through every part of the lungs. From the extreme branches of the pulmonary artery, a- fife the fmall branches of the pulmonary veins; which as they approach the left auricle of the heart, unite in fuch a manner as the pulmonary artery divides going from the heart, only that the veins enter the mufcular appendix of the left auricle in feveral branches, and the blood being brought back from the lungs by thefe veifels to the left auricle and ventricle of the heart. Of the arteries and veins. 199 heart, it is from the left ventricle of the heart thrown into the Aorta. Aorta, or great artery, arifes from the left ventricle of the heart, and deals out branch- es to every part of the body. The firfl part of this veflel, is called Aorta Afcendens ; it paflfes over the left pulmonary artery, and veins and branch of the Afpera Arteria, and being refleded under the left lobe of the lungs, it commences Aorta Defcendens; which name it Iceeps through the Thorax and Abdomen where it pafles on the left fide of the fpine, till its di- vifion into the iliac arteries between the third and fourth Vertebra of the loins. From under two of the femilunar valVes of the Aorta, which is e'er it leaves the heart, a- rife two branches (fometimes but one) whicl; are bellowed upon the heart, and are called Co- fonari^ Cordis. From the curved part of the Aorta, which is about two or three inches above the heart, arife the fubclavian and carotid ar- teries j the right fubclavian and carotid in one trunk, but the left fmgle. By fome authors thefe vefTels have been defcribed in a different m^anner, but I believe their defcriptions were, for want of humane bodies, taken from brutes ; for i have never yet feen any variety in thefe VeiTels in humane bodies, though I have in the veins nearer the heart : And indeed there feems to me to be a mechanical neceffity for their go- O 4 ing 200 Of the arteries and veins. ing off in the manner here defcribed inhumane bodies j for the right fubckvian and carotid arteries necelTarily going off frorn the Aorta at a much larger angle than the left, the blood would move more freely into the left than the right, if the right did not go off in one trunks which gives lefs fridion to the. blood, than two branches equal in capacity to that one, fo that the advantage the left have by going off from the Aorta, at much acuter angles than the right, is made up to the right by their go- ing off at firft in but one branch. The carotid arteries run on both fides the Larynx to the fixth Foramina of the fcuU, through which they enter to the brain-, but as they pafs through the neck, they detach branches Xo every part about them, which branches are called by the names of the parts they are be- llowed upon, as, Larynges, Thyroide^, Pha- ryngeae, Linguales, Temporales, Occipitales, Faciales , &c. but juil before they enter the lixth Foramina of the fcull, they each fend a fmall branch through the fifth Forami- na of the fcull to that part of the Dura Mater which contains the Cerebrum. It is thefe ar- teries which make thofe. imprefllons which are fo conflantly obferved on the infide of the Of- fa Bregmatis : Thefe branches Mr. Monro ob- . ferves oftner arife from the temporal arteries. The internal carotids, fend two branches %o the Of the arteries and veins. i o i the back part of the nofe, and feveral branches through the firfl and fecond Foramina of the fcull to the face and parts contained within the orbits of the eyes, and then piercing the Dura Mater, they each divide into two bran- ches, one of v/hich they fend under the Falx of the Dura Mater, between the two hemif- pheres of the brain, and the other between the anterior and poilerior lobes. Thefe branches take a great many turns, and divide into very fmall branches in the Pia Mater before they en- ter the brain, as if large trunks would make by their pulfe too violent an imprelTion on fo ten- der and delicate a part. And perhaps it may be from an increafe of the impulfe of the arte- ries in the , brain, which Urong liquors, produce, that the nerves are fo much interrupted in their ufes throughout the whole body, \^j\^^tn a man is intoxicated with drinking \ and it may alfo be from alike caufe, that m.en are delirious in fevers. Befides tliefe two arteries., viz. the carotids, the brain has two more, called Cervl- caies, which arife from the fubclavian arteries, and afcend to the head through the Foramina, in the tranfverfe procelTes of the cervical Ver- tebra, and into the fcull through the tenth or great Foramen •, thefe two arteries uniting foon after their entrance, they give off branches to the Cerebellum, and then pafTing forward, di- vide and communicate with the carotids \ and the , 20Z Of the arteries and veins. the carotid arteries communicating with each other, there is an entire communication be- ^ tween them all ; and thefe communicant bran- ches are fo large that every one of thefe four great vefTels, with all their branches may be^ filled with wax inje6ted through any one of tjiem, as I have often experienced. The fubclavian arteries, are each continu- ed to the cubit in one trunk , which is called Axillaris as it paffes the arm-pits, and Hu- meralis as it paffes by the infide of the Os Hu- meri, between the mufcles that bend and ex- tend the cubit. From the fubclavians withih the breaft arife the Arteri^ Mammarias, which run on the infide of the Sternum, and lower than the Cartilago Enfiformis. As foon as the Arteria Humeralis has paffed the joint of the cubit, it divides into two branches, called Cu- bitalis Superior and Cubitalis Inferior; which latter foon fends off a branch, called Cubitalis Media, which is beftowed upon the mufcles feated about the cubit. The Cubitalis Supe- rior paffes near the Radius, and round the root of the thumb, and gives one branch to the back of the hand, and two to the thumb, one to the firfl finger, and a braiich to communi- cate with the Cubitalis Inferior. The Cubi- talis Inferior paffes near the Ulna to the palm of the hand, where it takes a turn, and fends one branch to the out-fide of the little finger, another Of the arteries and veins. 203 another between that and the next finger, di- viding to both, another in the fame manner to the two middle fingers, and another to the two fore-fingers. Thefe branches which are be- itowed on the fingers, run one on each fide of each finger internally to the top, where they have fmall communications, and very often there is a branch of communication between the humeral and inferior cubital arteries. Thi^ communicant branch is fometimes very large, and liable to be pricked by carelefs or inju- dicious blood-letters, in bleeding in thebafilic vein, immediately under which, as far as I have been able to obferve, this branch always lies. Mr. Monro has found the fubclavian artery divided in one fubjedt into two, the exteri- or of which formed the Cubitalis Superior, and the inner artery, the Cubitalis Inferior; from which ftrudiure he accounts for the fuccefs in the operation of the aneurifm fometimes per- formed above the cubit. When the operation for an aneurifm is made upon this communi- cant branch, it is neceflary to tie it on both fides of the orifice, becaufe the blood is liable to flow freely into it either way. From the defcending Aorta on each fide is fent a branch under every rib, called Inters coftalis, and about the fourth Vertebra of the back, it fends off two branches to the lungs, called Bronchiales, which are fomtimes both S given 204 Of the arteries and vetns. given off from the Aorta, fometimes one of them from the the intercoftal of the fourth rib on the right fide \ and as the Aorta pafTes under the diaphragm, it fends two branches in- to the diaphragm, called. Arterise Phrenic^, which fometimes rife in pne trunk from the Aorta, and fometimes from the Coeliaca ; but oftner the right from the Aorta, and the left from tlae. ccgliac. Immediately below the dia- phragm arifes the coeliac artery from the Aor- ta; it foon divides into feveral branches, which are beflowed upon the liver. Pancreas, fpleen, flomach, Omentum, and Duodenum. Thefc branches are named from the parts they are beflowed on, except two that are beflowed upon the flomach, which are called Corona- ria Superior and Inferior, and the branch be- ilowed upon the Duodenum, which is named Intefllnalis, .\At a very fmall diflance below the Arteria Cceliaca from the Aorta, arifes the cMefenterica Superior, whofe branches are be- flowed upon all the Inteflinum Jejunum and Ileum, part of the Colon, and fometimes one branch upon the liver. A little lower than the iiiperior mefenteric artery, arife the emulgents, which are the arteries of the kidneys. And a little lower thp.n the emulgents, forward from the Aorta, arife the Arteris Spermaticas. For which, Vid. chap, of the parts of the genera- don in men. Lovs^er laterally, the Aorta fends branches Of the arteries and veins. 20 j branches to the loins called Lumbales, and one forward, to the lower part of the Colon and the Re6lum , called Mefenterica Inferior. Between the Arteria Co^liaca Mefenterica Su- perior 5 and Inferior and the branches of each near the guts, there are large commu- nicant branches to convey the blood from one to another when they are either compref- fed in any pofture, or flreightned by being ftretched out in ruptures, or from any other caufe. As foon as the Aorta divides upon the loins, it fends off an artery into the Pelvis upon the Os Sacrum, called Arteria Sacra, and the bran- ches the Aorta divides into, are called Iliacse, which in about two inches fpace divide into ex- ternal and internal. The Iliacas Internas firfl fend oft the umbilical arteries which are dried up in adult bodies, except at their beginnings, which are kept open for the collateral branches on each fide, one to the bladder, and one to the Penis in men, and in women the Uterus ; the reft of thefe branches are beftowed upon the buttocks, and upper parts of the thighs. The Iliacae Externse, run over the Ofia Pubis into the thighs;- and as they pafs out of the Abdo- men , they fend off branches , called Epiga- ftricas, to the forepart of the integuments of the Abdomen under the Redti mufcles. And the epigaftrick arteries fend each a branch into the io6 Of the arteries and veins. ^ : I the Pelvis and through the Foramina of the Of- fa Innominata to the mufcles thereabouts. As foon as the iliac artery is pafled out of the Ab- domen into the groin, it is called Inguinalis , and in the thigh Cruralis , where it fends z, fj^ large branch to the back-part of the thigh ^ ' but the great trunk is continued internally be- tween the flexors and extenfors of the thigh, and palling through the infertion of the Triceps mufcle into the ham, it is there called Popliteaj then below the joint it divides into two bran- ches, one of which is called Tibialis An tica^ it paiTes between the Tibia and Fibula to the fore-part of the leg, and is bellowed upon the great toe, and one branch to the next toe to the great one, and another between thefe toes to communicate with the Tibialis Poflica •, which artery foon after it is divided from the Antica, fends off the Tibialis Media, which is beftow- ed upon the mufcles of the leg, while the Ti- bialis Poftica goes to the bottom of the foot and all the lefTer toes. The Tibialis Antica is difpofed like the Cubitalis Superior ; the Pofli* ca, like the Cubitalis Inferior; and the Media in each, have alfo like ufes. Thefe arteries which I have defcribed, are uniform in moll bodies, but the lelTer branches are diilributed like the branches of trees, and in fo different a manner in one body from another, that thefe veffel^ ,, it is highly probable, are. in no two bodies Of the arteries and veins. 207 bodies alike, nor the two fides in any one body. I HAVE oncefeen a rupture of matter, and once of blood and matter, which flowed out of the Abdomen into the fore-part of the thigh, through the fame pafTage at which the iliac ar- tery goes out of the Abdomen. The veins arife from the extremities of the arteries, and make up trunks which accompa- ny the arteries inalmoft every part of the body, and have the fame names in the feveral places which the arteries have, which they accompany* The veins of the brain unload themfelves into the Sinufes, (Vid. chap, of the Dura and Pia Mater) and the fmufes into the internal jugu- lars and cervicals, and the internal jugulars and cervicals into the fubclavians, which joining, make the Cava Defcendens. The internal ju^ gulars are feated by the carotid arteries and re- ceive the blood from all the parts which the carotids ferve, except the hairy fcalp and part of the neck, whofe veins enter into the exter- nal jugulars, which run immediately under the Mufculus Quadratus Genge, often two on each fide* The cervical veins, defcend two through the Foramina in the tranfverfe procefTes of the cervical Vertebra, and two through the great Foramen of the fpine, and one on each lide. the fpinal marrow -, thefe join at the lowed: Ver- tebra of the neck, and then empty into the lub- . clavians., 2o8 Of the arteries and veins. davians, and at the interftices of all the Verte- brse communicate with one another. The veins of the arm are more' than double the number of the arteries, there being one on each fide each artery, even to the fmalleft bran- ches that we can trace, befides the veins which lie immediately under the fldn. Thofe which accompany the arteries have the fame names • with the arteries , thofe which run immediate- ly under the flcin on the back of the hand have no proper names, they run from thence to the infide of the elbow; where the uppermofl is called Cephalica, the next Mediana, the next Bafilica. Thefe all communicate near the joint of the elbow, and then fend one branch which is more diredlly from the Cephalica, and bears that namie, until it enters the fubclavian vein ; it paiTes. immediately under the fkin, in mofl bodies, between the flexors and extenfors of the cubit, on the upper fide of the arm. The other branches joining, and receiving thofe which accompany the arteries of the cubit, they pafs with them by the artery of the arm into the fubclavian vein. The external veins have frequent communications with the inter- nal, and are always fulleft when we ufe the moft cxerclfe; becaufe the blood being expanded by the heat which exercife produces , it re- quires the veffels to be diftended, and the in- ner vefTels, being comprefTed by the actions of the Of the arteries and veins. 209 the mufcles, they cannot dilate enough, but thefe vefTels being feated dn the out-fides of the mufcles, are capable of being much dilat- ed; and this feems to me to be the chief ufe of thefe external vefTels. The Cephalick vein as it ruhs up the arm, is very vifible in moft men, but in children is rarely to be feen ♦, there- fore great care fhould be taken not to wound it in the cutting of iffues in childrens arms-, and I know no way to be fure of avoiding it, but by cutting the ilTue more externally than is ufual in men, which may be doile Without any inconvenience;. In the Thorax, belidesthe twoCava's, there is a vein called Azygos or Vena Sine Pari, it is made up of the intercoftal, phrenic, and bron- chial veins, and enters the defcending Cava near the auricle, as if its ufe was to divert the de- fcending blood from falling too diredlly upoii the blood in the afcending Cava, and diredt the blbod of the defcending Cava into the au- ricle. Befides this vein in the Thorax, are the mamniary veins, one to each artery; and the veins of the heart which are called Coronarise ; they are twice the number of the ai-teries , but they enter the right auricle chiefly at one orifice. In the Abdomen, (befides the Cava Afcen- dens, and the veins which are named like the arteries, viz. The emulgents from the kidneysji 2IO Of the arteries and veins. the lumbal and fpermatick veins, the Sacra, iliac and hypogaftrick veins) there is one large one called Vena Portse, whofe branches arife from all the branches of the coeliac and two mefenterick arteries, except the branches of the coeliac and fuperior mefenterick, which are beflowed on the liver, and uniting in one trunk enters the liver and is there again diftributed like an artery, and has its blood colleded and brought into the Cava by the branches of the Cava in the liver ; this vein being made ufe of inftead of an artery, to carry blood to the li- ver, for the feparation of bile. It moves in this vein about eight times flower than in the ar- teries hereabouts ; and this flow circulation be- ing fuppofed neceffary, I think, there could be no other way fo fit to procure it ; for if an artery had been employed for this ufe, and been thus much dilated in fo Ihort a pafTage, the blood would not have moved uniformly in it, but much faller through its Axis than near its fides ; and befides it is very probable that the blood in this vein having been firfl employ- ed in nourifhing feveral parts, and having through a long fpace moved flowly, may be made much fitter for the feparation of bile than blood carried by an artery, dilated to procure a circulation of the fame velocity with that in thisvein. In Of the arteries and veins. 21 I In the leg the veins accompany the arteries in the fame manner as in the arm, the external veins of the foot being on the upper fide, and from them is derived one called Saphoena, which is continued on the infide of the limb its whole length, and hasfeveral names given it from the feveral places through which it pafTes. The arteries are faid to have three coats, a middle mufcular, and an external and internal membranous. The veins are faid to have the fame ; • the internal coat of an artery may be pretty eafily feparated, but not the external ^ and though the veins have mufcular fibres, yet 1 could never feparate any one diilindly into three coats ; and iri the infide of the veins there are many valves, efpecially in the lower limbs, to hinder any reflux of the venal blood, which otherwife would have happened from the fre- quent adlions of the mufcles on the outiides of the veins \ and both the arteries and veins as they run in the infide of a limb, or as they are difperfed in parts that fuffer great extenfionSj as the ftomach, guts and Uterus, they are bent in and out fo much as that when thefe paxts come to be diilended, they may comply with thofe diftentions, by only being ftreightened^ and fo preferved from being ilretched, which Would lefTen their Diameters. The fmall ar- teries near the heart go off frqm the large trunks at obtufe angles, farther at lefs obtufe P 2 angles^ 2 12 Of the arteries and veins, . • angles, then at right angles, farther ftill at a- cute angles, and near the extremities at very acute angles, becaufe the blood in the vefTels far from the heart moving with lefs velocity than the blood in the veiTels near the heart, the blood in the collateral branches more remote from the heart wants the advantage of a di- " re6ter courfe \ and becaufe a very large branch arifmg out of another, might weaken too much the fides of the veffel it would arife from *, that . inconvenience is prevented by encreafmg the number, and fo leifening the fize of the colla- teral branches,where otherwifeone large branch would have ferved better •, as in the going off of the fubclavian and carotid arteries, which might have gone off for fome fpace in one trunk; but this mechanifm is more evident in the going off of the Arteria Coeiiaca and Mefenterica Su- perior. And the fmall arteries always divide fo as that the leiTer branch may lie leaft in the dire6i:ion of the blood flowing into them, which makes the blood flow mofl freely into that branch, that has fartheft to carry it \ and the fmaller branches arife more or lefs obliquely, from the fides of other arteries, according to the proportion they bear to the arteries they arife from, becaufe an artery com^paratively large arifing obliquely from the fide of another, would make an orifice in that it arifes from too large and weaken it. And both thefe ends 6 are Of the arteries andvems. 213 are at once brought about, by making the ar- teries that give off the branches, bend more or lefs towards the branches they give off, ac- cording to the comparative magnitude of the branches given off. BoRELLi has computed the force which the heart exerts at every Syflole, to be equal to three thoufand pounds weight, and the force which all the arteries exert at every Syftole, to be equal to fixteen thoufand pounds weight, and that they together overcome a force equal to a hundred and thirty fix thoufand pounds weight ; and Dr. Keill has computed that the heart in every Syftole, exerts a force not ex- ceeding eight ounces, (but in both thefe ac= counts a weight in motion is compared to a weight at reft.) The firft computation was made by comparing the heart with other mu- fcles, whofe power to fuftain a weight could be beft determined •, and the latter was made from the velocity of the blood moving in an artery : Therefore if we confider that Borelli's way of computing led him to find out the ab- folute force of the heart, and Dr. Keill's the force which the heart ufually exerts, perhaps thefe very different computations may be ac- counted for -J for if the force of the heart, which is conftantly exerted, iliould, compared with any other mufcle, be but in a reciprocal pro- portion to the frequency of their adions, and P 3 the 2 14 Of the arteries and vems. the importance of their ufes j may not the heart very fitly have a force vaftly greater than ufually it exerts, becaufe it is always in adion, and mufl be able to exert a certain force in the loweil ftate of health? What force the heart ever exerts in a grown man, I cannot fay-, but it muft be lefs in each ventricle than is fuffici- ent to burfl the valves, which hinder the blood from returning into the auricles out of the ventricles, or than is fufficient to break thofe threads by which thefe valves are tied to the Papilla. In a dog I found the force which the heart would exert, would not raife to one foot perpendicular heighth, a column of blood through the Aorta Afcendens. And when I inje6t the Arteries of a child, I find a force exceeding little will throw water through all the velTels, with a velocity equal to that with which the blood moves in thofe velTels when living. And if the heart like other mufcles can perform the firfl part of its contraction with moil eafe, is not the quick a6lions of the heart in hedtic fevers owing to its not being able to " empty the ventricles every Syflole, which I think wall oblige it to a6t Cseteris Paribus fo much the oftner. For the following ingenious attempt to account for the Syflole and Diaflole of the heart, and the reciprocal anions of the auricles and ventricles, I am obliged to Mn Monro. Po S T U- Of the artenes and veins, 2 1 y " Po s T u L A T A, that the adion of the mu- " fcles depends on the influx of blood and " Liquidum Nervofum into the mufcular fi- *' bres, and therefore whenever the mufcles " are deprived of either or both thefe fluids, *' their adbion ceafes ; this a great many au- " thors have fully proved by tying and cut- *' ting the nerves or artenes that ferve any " mufcle. That alJ mufcles are in a conilant " Hate of contradlion as long as blood and the " Liquidurn Nervofum are freely *fupplyed to " them, which feems evident from the Sphin- " 6ler Ani and Vefics, and from the continued " contradion of fuch mufcles, whofe antago- *' niflis are cut afiiinder or paralitic. That the " nerves of the heart run to it between the " auricles and arteries, and that the Arterise " Coronarias rife from the Aorta behind the ** Valvule Semilunares, both which are evi- " dent from diflfedions. If then both auricles " and ventricles are ready, upon the firll com- " munication of motion, tocontra6t at the fame " time, the ventricles, asDr.Keilwellobferves, " being flironger, will firH contradl and hinder " the contradtion of the auricles, which maift " be in the mean time, much dilated by the " influx of blood from the veins, while the " arteries are alfo diftended by the blood ^^ thrown out of the ventricles; therefore the " cardiack nerves lying between ^e two will p 4 ^^ be 2i6 Of the arteries and veins. " comprefled , and the courfe of the liquids '•'- in them ilopped^ at the fame time the blood •" that rullies out of the left ventricle into the '' Aorta, puihes the valves of that artery up- ^' on the orifices of the Arterise Coronarias, fo ^'' that no blood can enter into the fubftance *' of the heart : Thus both caufes of contraction . ^^ failing, this mufcle muft become paralitick. '^^ The refifbance then to the contradion of the ^' auricles being now removed, they will throw " their blood into the ventricles; and the im- ' '^^ pulfion of the blood into the arteries from ^' the heart now alfo ceaiing, the two gre^t '^^ arteries will be conftrided : The nerves are ^' therefore now again free from cpmpreflion, *' and the valves of the Aorta being thruft " back upon the mouth of the ventricle, the ^^ blood enters the Arteriae Coronarias; fince the ^^ ventricles are again fupplied wiph both the *' liquids, on which their contradlion depends, *' they muft again acl. And thus as long as thefe ^' caufes continue , their effeds muft follow, " i. e. as long as the creature lives the heart *' muft have an alternate Syftole and Diaftole, *' and the auricles and ver4ricles have reci- ■^^ procal adions " If the arteries contradl fuppofe a fourth part of the fquares of their diameters at every Syftole, and if the heart does not throv/ out a quantity ai; ^very Syftole, equal to the fourth part of the Of the arteries and veins. 217 the folid contents of all the arteries when dilateci, it is evident the heart does not throw the blood through the whole arterial fyftem, but into fo much of the arteries neareft the heart, as will contain four times as much as is thrown out of the left ventricle at once; and then this portion of arteries throws the blood forwards and dilates the arteries that lie next, and fo on : But if the capacities of all the arteries taken together in their utmoft dilatations, exceed their capa- cities in their utmoft contradtions, juft fo much as the quantity of blood amounts to, which is thrown out of the left ventricle of the heart at every Syftole, then every contradlion of the heart propels the blood through the whole ar- terial fyftem, and the pulfation of the arteries thus made, will begin at the Aorta immedi- ately after the ventricle begins to contra6b, and fo go on fucceflively to their extremities ; and while the left ventricle of the heart dilates a- gain they will contrail, and the times of the Syftole and Diaftqle of the heart and arteries always be reciprocal, The fedions of all the remoter vefTels, being greater than a fedlion of the Aorta, the blood will move fo much flow- er in the lefTer velTels than in the greater, as the fedions of the lefier veiTels taken together, exceed the fe6l:ion of the greater velTel or vef- fels. , The ftrength of the coats of the arteries if the blood preiTed equally againft the fides of 2 1 8 Of the arteries and veins, of them all, Casteris Paribus, ought to be one to another as their circumferences, becaufe fo much as the circumference of one artery is greater than another, fo much greater prefTure its fides muft fufbain ; but the arteries nearefl: the heart, fuflaining the readlion of all the arterial blood, they muft have a flrength yet greater than in that proportion: And the vefTels, both arteries and veins, the more diftant they are from the head, the greater proportional Strength their coats muft have, becaufe the arterial and venal blood communicating, they will prefs upon the lower vefiels, with a force proportional to the perpendicular altitude of blood above, which will be that of the perpendicular altitude of the whole body ; for though the afcending blood of the ateries may be faid not to prefs upon the defcending, becaule it moves another way, ne- verthelefs it being thrown from the heart into one common velTel, which afterwards divides, the blood moving both ways communicates, and that force which is necefiary to overcome the natural inclination of the afcending blood to defcend, will be imprefled alfo upon the de- fcending blood, which is juft the fame with the weight of the afcending blood y and the veins both from above and below communicating at the right auricle, the prefTure in them will alfo be as the perpendicular altitude of the body. So that the blood in all the veins and arteries may be Of the arteries and veins. z i ,9 be compared to a fluid in a curved tube, in which that partin one leg, exadly balances that in the other, and both prefiing moil upon thofe parts which are neareil the center of the earth. 'Accordingly we find by experience, that hu- mours are moft apt to flow to the lowefl parts, arid that by laying thofe parts upon a level with 'Hit whole body, this inconvenience is remedi- lexl, but laying a leg only' in a chair does it but in part, juft fo much as thetperpendicular altitude of the body frpm'xhat part is fliortened. There is alfo to be cohTidered concerning the thick- nefs of the coats.of "the veffels, that the blood moving flower in the fmall veiTels than in the great, the moment of the blood againft the fides of a fmall veiTel, will be as much lefs than the moment of the blood againfl equal parts of a great one, as the velocity of the blood in a fmiall vefTel is lefs than that in a great one ; and therefore their coats may alfo differ from the former proportion, as the velocity of the blood differs. Moft of the fmall vefiels in the limbs lying againfl one another are a mutual fupport, and therefore lefs liable to be dilated or burft than capillaries which lie in the thin membranes of cavities, fuch as in the nofe. Hence thefe I fuppofe are moil fubje6l to hae- morrhages. And if haemorrhages of blood do frequently arife from obilru6lion3 in the minut- eft veiTels, does it not appear how opium and the no Of the artenes and veins. the bark, if they thin the blood inwardly taken (as they do moft powerfully when mixed with it) come to be fo often effedlual remedies in that cafe? And the coats of the leffer veffels. being proportionably weaker than the great ones, according to the decreafe of the veloci- ty of the blood, which lelTens the moment with which it moves in them, whenever the blood begins to move in them with an equal velocity^ or greater, as it happens after an amputation when the great veffels are tied, the force of the blood often overcomes the flrength of the coats of the fmaller veffels, and dilates them fo, that fometimes thofe' veffels, which fcarce bled during the operation, will in a few hours bleed vehemently. And this conflant effort of the blood to dilate veiTels upon theobflrudlions of others, I take to be one reafon of thofe throb- bing pains which are felt in wounds when the bleeding is flopped, and in all violent Inflamma- tions, until the collateral branches are dilated, or the tenfion of- the parts otherwife taken off. The extream branches both of the arteries and veins have very numerous communications, like thofe in the Stamina of the leaves of plants, by which communications the blood that is ob- llrudied in any veffels, may pafs off by other veffels that are not obftrudled •, and fmce the moment of the blood in the veffels leifens, and ^the friction from the veffels encreafes as it ap- proaches Of the arteries and veins. m proaches the extremities j and fince many of the lefler vefiels are more expofed to prefiiire than any of the large ones, thofe communica^ tions in the lefTer v-elfels are made fo much the more numerous. By means of thefe communi- cations, the blood circulates in a limb that has had part amputated, and into any vefiels that have been feparated from the trunks that fup- plied them, which otherwife mull have mor- tified for want of nourifhment, and with them for the fame reafon, all the branches that arife from fuch feparated velTels ; and I can difcern no other way than by thefe communications, that the fluids contained in a large inflamma- tion, can fuppurate into one cavity. If we injed by the arteries a large quantity of a coloured fluid, we find all the large veins full of that liquor, before any of the folid parts are much coloured with it; and upon frequent repetitions all of them much lefs coloured than I think might be expe6led, if it had gone into any thing near all the vefTels of the body ; and I have often thrown wax or tallow coloured with vermiUion or verdigreafe, through all the ar- teries, and back again through the veins, even to the heart, every where filling veiTels that cannot be difcerned without a microfcope ; and all this without filling or much difcolouringany one entire part. In viewing with a microfcope the" circulation of the blood in the tail of a fifh, the 2 2 z Of the arteries and veins. the eye eafily traces arteries to their extremis ties, and their return in veins; yet all the veffels we can fee make but a fmall part of the whole of what we fee \ and though we are taught that the whole animal body, is a compages of vef- fels fuch as we fee : If it were fo, I think we could not well diftinguifh any; and if the fumof the diameters of all the veffels we can fee, are to that of the breadths and thickneffes of all the reft of the parts, which we fee at the fame time, taken together, but as one to five, thefe veffels then are no more than the twenty fifth part of what we fee with them. What then fhall we fuppofe the reft of the tail, and thofe parts which were fo little tinged, and thofe which were not filled with wax, in the foregoing experiments, compofed of? Are they not com- pofed of veffels which arife from the arteries, as excretory duds do in a gland but terminate in the veins ? And thefe veffels being only to convey the nutritious juices, and what elfe may be a proper vehicle for them, is it not fit the circulation in them fhould be exceeding flow, that the nutritious particles may adhere the eafier to the fibres of the veiTels, which they are to augment or repair? Befides, if any whole part was made up of blood veffels, or any other Veffels with fiuids moving fwifdy in them, it feems to me impoffible, that one part of a limb can be very cold while another part is hot, if the OJ the arteries and veins. 223 the warmth of the parts is owing to the fluids they contain. And if there are fuch vefTels as thefe, the velocity of the motion of their fluid will not depend upon any proportion they bear to the vefTels they arife from, but upon the ve- locity with which their fluids are feparated from the arteries into them, and the proportion of the fedions of all their orifices to the fum of their own fedions , at any diftance where we would compare the velocity of their fluid. And the ftrength of th^ coats of thefe veflels, may not only be as much lefs than the flrrength of the coats of an artery, as their diameters are lefs, but alfo lefs I think in that proportion * in which the velocity of their fluids is lefs, and the motions more uniform, than the velocity and motion of the blood in an artery. The coats of the veins are much thinner than thofe of the arteries, comparing veflels whofe fed:ions are equal, becaufe the blood moving flower in the veins than the arteries, it prefles with lefs moment againfl: their fides : And be- fides, the blood in the veins has nearly an equal uniform motion, but in the arteries a very une- qual one, and that will require a farther difi^e- rence in the fl:rength of their coats; for thofe of the arteries mufl: be equal to the greatefl: na- tural preflure ; and if the arterial blood propels the venal, that is another reafon for the diffe*- rent ftrength of their coats. 8 All. 2 24 ^f ^^- arteries and veins. All thefe things being confidered, it ap- pears to me to be an exceeding diftiGuk thing to determine nearly, what proportion the flu- ids of an animal body bear to the folids, or to determine what proportion the fum of all the areas of the minuteft arteries bear to the Aorta, without which I think we can neither determine the' comparative velocity of the blood moving in the different vefTels, nor the quantity of blood in any animal body, nor the time iri which the whole mafs of blood, or a quantity equal to the whole mafs is flowing through the heart. But if each ventricle of the heart holds five ounces of blood, and they are filled and emptied every Syfl:ole and Diafliole, which I think is true, and if eighty pulfes in a minute be allowed to be a common number, there then flows twenty five pounds of blood through each ventricle of the heart in a minute. Dr. Keil has fhewn that the fum of all the fluids in a man exceed the fum of all the folids, and yet the quantity of blood which all the vifible arteries of a man will contain, is lefs than fout pounds; and if we may fuppofe all the vifible veins, including the Vena Port^, hold four times as much, the whole then that the vifible vef- fels can contain, is not twenty pounds; but the whole that they do contain, is but very little more than the veins can contain, feeing the ar- teries are always found almoft empty in dead bodies, Of the arteries and veins, 2 x 5 bodies, but how much the invifible arteries and veins contain, I mean thofe which contain fuch a comp.ound fluid, as is found in the larger vefTels, I know no way to judge, unlefs we knew v/hat proportion thefe velTels bear to thofe that carry the nutritious juices and Serum, (if there are fuch) without the Giobuli of the blood. CiETERis Paribus, is notthe velocity of the blood in all animals proportionable to their quantity of adtion; and is not their neceflity of food alfo in proportion to their quantity of adion ? If fo, we may fee how it comes to pafs^ that animals which ufe no exercife, and v/hofe blood moves extreamly flow in the winter, can fubfift without any frelh fupply of food, while others that ufe a little more exercife, require a little more food, and thofe who ufe equal exer- cife winter and fummer, require equal quanti- ties of food at all times, the end of eating and drinking, being to repair what exercife and the motion of the blood has deftroyed or made ufelefs *, and is not the lefs velocity of the blood in fome animals than in others, the reafon why wounds and bruifes in thofe animals do not fo foon deflroy life, as they do in animals whofe blood moves fwifter? CL CHAP, ii6 C H A P. X. Of the lymph iedti^is. LYmph^ducts are fmall pellucid cylin- drical tubes which arife invifible from the extremities of the arteries throughout the whole body, but more plentifully in glands than other parts, and in greateft number from fuch glands as feparate the vifcideft fluids, as may be ob- ferved in the liver and Tefles. They cannot be difcerned in a natural flate to have more than one coat, and that exceeding thin, having valves at fmall and uncertain diflances, to prevent the regrefs of their fluid. They have frequent com- munications like the veins, but do not unite fo often •, the larger trunks are in many places attended v/ith fmall glands, through which they run, and at the fam.e time fend communicant branches over them, that they might be fecu- red againft obfl:ru(5lions from difeafes in thofe glands. They all terminate in the Via Ladea, or in the large veins. All that rife in the Ab- domen empty into the Vense Ladese Secundi Generis and Receptaculum Chyli ^ thofe in the cavity of the Thorax into the Dudus Thora- cicus and the fubclavian veins. Their ufes are to carry lymph to dilute the chyle, to make it incorporate more readily with the blood (but Of the hjmph^duBs. 217 (but not to make it flow the better in the Lac- Ceals, as appears fufficiently from their not en- tering into the minuteft Ladieals) and to carry off To much lymph as is neceffary to leave the blood in fit temper to flow through the veins ; for it is always obferved that in fuch perfons as have their blood too thin, the Globuli cohere and form Molecule or polypufes, which I ima- gine muft arife from the Globuli of the blood not rubbing often enough, and with fulficicnt force one againft another to difunice them as fail as they cohere. Thefe polypufes are frequent- ly found in all the large veins, and in the right auricle and ventricle of the heart, efpecially in fuch bodies as die of chronic difeafes. Authors have hitherto defcribed and painted thefe veflels like ftrings of poppies, as they appear when injected with mercury; becaufe the coat of thefe veiTels being exceed- ing thin, it is not able any where between the valves to refifl the mercury's attracting ix.{€i{ into globules : And the fame appearance alfo happens when they are preternaturally diilend- e-d; becaufe the valves hindering a diilention • where they are feated, the fpaces between them approach to a fpherical figure from the equal prelfure of the fluid, according to the degree of their diftention ; but in a natural (late v/hen they are filled with lymph, or when they are moderately injeded with air or water, they.al- 0^2 ways 2x8 Of the hmphddduBs. ways appear as cylindrical as the veins. Any ofthefe veiTels being burft, they caufe adrop- fie in the cavity into which they open, which is ofcener in the Abdomen than the Thorax. This kind of dropfie is fonietimes cured by tapping, and I believe the reafon why it no oftner fucceeds is, that it generally takes its rife from a difeafed liver. Out of a great number that I have opened, I remember but fev/ whofe livers appeared perfedly founds one of which being very extraordinary, I will re- late his cafe from his own journal. His way of life expofing him to drink more than he thought could be confident v/ith his health, he refolved on a fudden to forbear drinking any ftrong liquors ; and this being in winter time, and he catching fome colds in ftormy weather, he iiril became rheumatick and then dropfical \ and then he came to London for a cure, Odober 4. 171 o. He was tapped by Mr. Feme, who took away all the water, which was about five gallons ; but the Abdomen filling again very fail, he tapped him again, Odober 28. November 18. Decembers December 30. January 16. and on February 17. Mr. Feme being indifpofed, he was tapped by Mr. Wil- liam Smith; and on February 24. by Mr. Feme: On March 17. Mr. Feme and my felf, there being a rupture at the navel, opened that with a launcet, and let out all the water that way, 1 and Of the lymph^duBs. ZZ9 and endeavoured to make a Fiflinla there to prevent future tapping, but in vain, for when the belly was emptied of water , the orifice would clofe up 5 he not being able to bear a fponge-tent to keep it open •, and on March 24. 171 1, we opened it again at the navel with a launcet, and on April 7. Mr. Feme opened the navel, and again on April 22. at which time .there being accidentally prefent one Mr. Spir- ling a barbar, who pretending to furgery, and having obferved how Mr. Feme did it, un- dertook to make the aperture in the fame man- ner, which was by pinching up the ilcin, and Gutting of it as is ufually done in making of iifues; this wag on April 30. he performed it again in about May 20. And again on June 1 1. but he not doing it to the captain's fatisfaction was after this time difcharged, and Mr. Feme was defired to do the operation again; but the gentleman being farther in the country than Mr. Feme could conveniently go, I was de- fired to attend him, which I did afterwards, and tapped him on June 25. July about 4. or 5. July 16. July 26. Auguil 2. Auguft 11. Auguil 18. Auguft 25. September i. September 8. September 15. and on September 17. the wa- ter burft out of it felf I opened it again on September 27. a few days after which he died, after twenty nine times tapping and once open- ing it felf. At all which times he loll above 0^3 feventy 230 Of the Ijmph^duBs. feventy gallons of water. When he was firft tapped he was fo weak he could fcarce fit in a chair •, but he foon gathered flrength, went in- to the country, and drove himfelf in a chaife : About the feventeenth time he drove himfelf out of the country, and was tapped at my houfe, and drove himfelf home immediately after, and at other times would go out immediately after tapping. But for about three weeks before he died, he was almofl conftantly troubled with rheumatick pains, and bled frequently at the nofe, which feemed to be the moft immediate caufe of his death. Formerly in this operation -only part of the water was drawn olf at a time, and the tap fometimes left in the wound to draw off more, which was exceeding painful, and fome- times brought on a mortification; and if they drew off m^uch water at one time the patient v/as in great pain, and generally fainted, which was thought to proceed from the lofs of too riiuch of the liquor at once. But Dr. Mead obferving that thefe fymptoms could not pro- ceed from the lofs of an extra vafated fluid, foon found the true caufe, which was the fudden want of the prefTure of the abdominal mufcles againft the parts contained in the Abdomen; and in the year 1705. being then phyfician to St, Thomas's hofpital, ordered it to be tried there in the following manner: He dire6bed the Of the l)mphaducls. 231 the Abdomen to be preiTed by the hands of alTiilants while the water was running out, and afterwards kept rolled till the mufcles recover- ed force to do their office, and fo took out all the water at once without any inconvenience, which has made this operation not very pain= ful, often fuccefsful, and never dangerous. lopENED a woman who died of a drop- fy in the liver ^ in which I found the gib- bous part entirely wafted, and the coat of the liver about a quarter of an inch thick which contained about five gallons of a grofs yellow- ifh fluid, in which were many hydatids about the fize of goofeberries and fome pieces of mat- ter of as bright a red as vermilion. At about fourteen years of age fhe firft began to feel pain in this part which returned monthly, but m time grew continual, her belly conftantly en- creafingtill fhe died, which was in the twenty eighth year of her age, without ever having had her Menfes. All the other vifcera both in the Thorax and Abdomen were perfedtly found, nor was there the leaft fign of a dropfie in any of the limbs or yellownefs in the fkin, which is frequent in d^feafeis of the liver. 0^4 CHAP. 23X CHAP. XI. Of the lymphatic glands. TH E glands accompanying the lympha- tics, are fitiiated in the three cavities, in the interflices of the mufcles, where the lym- phatics lie vvith the large blood vefTels, and in the four cmunftories, viz. the arm-pits and groins. In the brain is feated the Glandula Pi- nealis, which I judge to be of this fort, having often feen large Lymphaeduds running into it from the Plexus Choroides; and at the bails of the brain in the Sella Turcica is the Glandula ^ Pituitaria, into which enters a large lympha- tic, as I imagine, named Infundibulum, (Vid. chap, of the brain.) In, the neck are fituated a great many of thefe by the fides of the caro- tid arteries and internal jugular veins, and two, or a fort of double one upon the Larynx im- -mediately below the thyroid cartilage, from v/hich iituation they derive the name of Thy- roidese, and juft within the Thorax is feated another called Thymus. In very young chil- dren the Thymus is as large or larger than the thyroid glands ; but in men thefe glands are very large, and theThymus very fmall, the for- mer having encreafed in about a double pro- portion of any other gland of this kind, and the Of the lymphatic glands, 233 the latter having rather diminifhed than en- creafed: But in brutes, fuch as have fallen un- der my obfervation, it is jull contrary. From which obfervations I am inclined to conclude, that they both belong to the very fame lym- phatics, and that either of them enereafmg as mu£h as both ought to do if both encreaf- ed, anfwers the fame end as if both did *, and that the reafon why the Thymus encreafes ra- ther than the thyroid glands in brutes, is be- caufe the fhape of their Thorax affords conve- nient room for it to lodge in ; and that in men the thyroid glands encreafed fo much becaufe there is no room in that part of the Thorax where the Thymus is feated for a large gland, to be lodged. In dogs, a porpufs, and fome other animals, I have feen the lymphatics in the Thymus and between the Thymus and Du6lus Thoracicus full of chyle , and fo in many other lymphatics near the Via I.adtea, Under the bafis of the heart, and at the fides of the lungs, where the great veiTels enter, arc many of thefe glands from the fize of a pea to that of a hazel nut. In the Abdomen upon the loins near the kidneys, and by the fides of the . iliac veiTels are many of thefe glands, which are called Lumbales, and there are fome at the hollow fide of the liver, named Hepaticse: And the mefentery is full of glands of a like appearance, but they feem to belong only to - the ^34 ^f ^^^ lymphatic glands, the ladeal veins, unlefs fome of them which arefeated at the Bafis of the mefentery among the Venae Ladleae Secundi Generis , belong to the lymphatics that come from the liver, where the hepatic lymphatics pafs in their way to the Receptaculum Chyli. The glands which accompany the blood veflels in the limbs are few, and diflributed in no certain order j, except thofe in the four emun<5lories, i. e. in the arm-pits and groins, named Axillares and Inguinales. Brutes have fome large ones in the thigh^ commonly called the pope's-eye ; thefe are feated about the great vefTels in the thigh, where they pafs through the Triceps mufcle. From this fituation, and not from any thing extraordinary in thefe glands it is that wounds are there fo dangerous. The lymphatick glands are faid by Nuck and others after him, to be compofed of veficles, and not of veflels like other glands ; and that thefe veficles are repo- , fitories of lymph: But from their appearance in a ' natural ftate which is very compadiE and uniform, •there feems to me to be but little reafon for fuch a conjedlure. Some have thought *their ufe tq be by contrading to accelerate the motion of, the fluid in the lymphatics ; but that does not feem very probable, becaufe a mufcular coat would have been the readied means to produce thut effedi befides, thefe veiTels feldom enter any Of the courfe of the aliment. 2 3 j any of them without detaching a branch over at the fame time perhaps to prevent obftruc- tions. And if thefe glands were endued with a contra6ling power, which is only prefumed without any proof, it would flill be difficult to conceive how fucha power applied at uncertain fpaces, fhould not rather obftrudt than accele- rate the motion of lymph in the lymphatics, unlefs there were valves to prevent a reflux ; and even then, if this were a convenient piece of mechanifm, it would be very flrange, it fhould no where elfe in the body be made ufe of C H A P. XII. Of the courfe t)fthe aliment and fluids ^ ahflraBed from the foregoing chap- ters. THE aliment being received into the mouth is there mafticated by the teeth, and impregnated with Saliva, which is prefTed out of the fall vary glands by the motions of the jaw and the mufcles that move it and the tongue. (See from page 151 to page 158.) Then it defcends through the Pharynx into the ilo.mach, where it is digeiled by the I juices 17^6 Of the courfe of the altment, juices of the flomach, (which are what is thrown out of the glands of its inmoft coat, and Saliva out of the mouth) and a moderate warmth and attrition. (See from page i6i, to page i66. Then it is thrown through the Pylorus or right orifice of the ftomach into the Duode- num, where it is mixed with bile from the gall- bladder and liver, and the pancreatic juice,, from the. pancreatic gland. Thefe fluids ferve farther to attenuate and dilute the digefted ali- nient, and probably, to make the fluid part fe- parate better from the Fseces. After this it is continually moved by the periilaltic or vermi- cular motion of the guts, and the compreflion of the diaphragm and abdominal mufcles, by which forces the fluid parts are prelTed into the lafteals, and the grofs parts through the guts to the Anus. (See from page 166, to page 168, and from 176, to page 181.} ^ The chyle, or thin and milky part of the aliment, being received into the lacleais from all the fmall guts, they carry it into the Recep- taculum Ghyli, and from thence the .Du6tus Thoracicus carries it into the left fubclavian vein, w^here it mixes with the blood, andpalTes with it to the heart. (See from page 182, to page 187.) All the veins being empiyed into tv/o branches, viz. the afcending and defcending Cava, they empty into the right auricle of the heart ; Of the courfe of the altment. 237 heart ; the right auricle unloads into the right ventricle, which throws the blood through the pulmonary artery into the lungs ; from the lungs, the blood is brought by the pulmonary veins into the left auricle, and from that into the left ventricle, by v/hich it is thrown into the Aorta, and diftributed through the body. From the extremities of the arteries arife the , Veins and lymphatics, the veins to colledt the blood and bring it back to the heart, and the lymphatics to return the lymph or thinner part of the blood, from the arteries, to the veins and the Via Ladea, where it mixes with the chyle, and then paiTes with it into the left fubclavian vein and to the heart. (See from page 193, to page 232.) All the fluids that pafs into the flomach and guts being carried into the blood-velTels, the greateli part of them are feparated and car- ryed oft by proper velTels, viz. urine from the kidneys, bile from the liver, &c. and thefe juices carry along with them whatever might be injurious to the animal (economy, (See frqm page 182, to page 187. CHAR 238 Of the Dura Mater. CHAP. Xlil Of the Dura Mater and Pta Mater. DUr A Mater, is a very compad ftrong membrane lining the infide of the fculi, firmly adhering at its bafis, and but lightly at the upper part, except at the futures. It has three proceiTes : The firfl named Falx, begins at the Crilla Galli, and runs backwards under the Sutura Sagittalis to the Cerebellum, di- viding the Cerebrum into two hemifpheres. Its ufe is faid to be, to fupport one fide of the Cerebrum from preiTing on the other when the head is inclined to one fide. But I think it is evident that this is not the ufe, becaufe there would be more need of fuch a procefs from one fide of the fcuH to the other, than this way; and it would be alfo very neceflary that it fhould run through the brain, to anfwer that end. The principal ufe appears to me to be to divide the brain into fuch portions as are leaft liable to be moved in the fcull, by any violent motions of the head, which is better done this way than it would the other; and the under-Ude of the brain is kept fteddy by the inequalities of the bafis of the fcull, which the brain is exadly fitted to. In brutes the Falx is always very fmall, there^^ fore in thofe whofe brains are of the larger fize, as Of the Dura Mater. 13P as oxen > flieep , horfes, &c. the upper part of the fcull is made uneven, exadly to fit the folds of the brain, which fecures the upper parts of their brains from conculTions, in the fame manner that the lower parts are fecured. The fecond procefs runs from the lower and back- part of the former to the upper edge of each Os Petrofum, and fuftains the poflerior lobes of the Cerebrum , that they might not com- preis the Cerebellum. In fuch rapacious ani- mals as I have diffedied, this procefs is bone. The third is very ^mall ; it runs from the laft: defcribed procefs dov/n towards the great Fora- men of the fcuil, and pofiefles the fmall fpace in the Cerebellum between the ProcelTus Ver- miformis. Thefe procefTes of the Dura Mater alfo ferve to keep the brain fleddy. The Dura Mater has in it feveral finufes , which are large veins to receive the blood from the leffer veins of the brain : Their number is uncertain, and thofe that are conflant are not defcribed in the fame order by writers. The firfl that prefents it felf is the Longitudinalis Superior, running from a blind hole a little above the Crifta Galli all along the upper edge of the Falx. A tranfverfe fedion of this vef- fel is not circular, like other vefTels, but a tri- angle whofe fides are arches of a circle •, the upper fide convex outwards, and the two lov/er convex inwards. The figure of this veiTel, is preferved 240 Of the Dura Mater, preferved by fmall ligaments running acrofs in the infide that it might not become conical, or cylindrical, like other vefiels, from the equal preflure of the contained blood, and thereby incommode the upper edges of each hemi- fphere of the Cerebrum. On the lower edge of this procefs is generally another very fmall one, called Longitudinalis' Inferior; this runs into the Re6lus, and when wanting is fupplied by a vein ; Redlus runs between the two firft procefTes of the Dura Mater, and unloads v/ith the Sinus Longitudinalis Superior into the two lateral linufes; but for the moll part the lon- gitudinal Sinus goes more diredlly into one of the lateral finufes, and the llreight Sinus into the other. There is fometimes a fmall one in the third procefs, which empties in the fame place with the former. From the endings of the longitudinal and ftreight fmufes, begin the two lateral fmufes, which when they come to the Os Petrofum, dip down andpafs through the eighth Foramina into the internal jugular veins. There is another named Circularis, it runs round the fore-part only of the Sella Tur- cica ', the two ends of this empty into four fr nufes, one on the top of each Os Petrofum, •which pafs into the Sinus Laterales, and one at the under fides of the fame bones, which pafs indifferently into both the lateral and cer vicai finufes, thefe two lail fmufes have al- ways Of the Pta Mater, 241 ways communicant branches. The cervical fi- nufes run from the bafis of the fcull through the great Foramen on both fides the Medulla Spinalis Colli, and through the tranfverfe pro- celTes of the cervical Vertebras 5 the laft of thefe have many times proper Foramina run- ning from the eighth Foramina to the back- part of the Apophyfes of the occipital bone- There are alfo two more of thefe veflels, which run from the circular Sinus between the Os Sphenoides and fore-part of the Os Petrofum' diredly into the internal jugular veins. Pi A Mater, is an exceeding iine mem- brane immediately invefting the brain even be- tween its lobes, hemifpheres and folds. It ferves to contain the brain, and fupport its blood-veflels, which run here in great numbers, for the arteries to divide into fmall branches upon, that the blood contained may not eiiter the brain too impetuoufly ; and for the veins to unite on, that they may enter the fmufes more conveniently. Between the Dura and Pia Ma- ter, is defcribedby feveral anatomilts, a mem- brane called Arachnoides, which may eafily be Ihewn at the back-part of the Cerebrum, upon "the Cerebellum and back-part of the Medulla Spinalis. I HAVE once feen a large part of the Dura Mater, and once part of the Pia Mater olTi- fied. R CHAP, 1^1 CHAP. XIV. Of the Cerebrum J Cerebellum^ Medulla Oblongata and Medulla Spinalis. CEREBRUM, is that part of the brain which poffcffes all the upper and fore-part of the Cranium, being feparated from the Cere- bellum by the fecond procefs of the Dura Ma- ter. Its upper fide is divided into two hemi- fpheres, and its lower fide into four lobes, two called anterior and two pofterior, which latter are much the largeft. At the meeting of the four lobes, appears the Infundibulum, which feems to be a lymphatick running from the ventri- cles of the brain into the Glandula Pituitaria, This gland is feated in the Sella Turcica. Im- mediately behind the Infundibulum appear two fmall bodies, named Protuberantise Duas Al- bas Pone Infundibulum. Between the two he- mifpheres of the Cerebrum, lower than the circumvolutions, appears a white body named Corpus Callofum. Under the Corpus Callo- fum, appear the two lateral or fuperior ven- tricles, which are divided into right and left by a very thin membrane, named Septum Lu- cidum, which is extended between the Corpus . Callofum and Fornix. The Fornix is a medul- lary body, beginning from the fore-part of thefe «..j»— ^ — : - • - -- Of the Cerebellum. 243 thefe ventricles, with two fmall roots which foon tLnite ; and running'towards the back-part, ^ where vhey divide into two parts, called Crura Fornicis. In the bafis of thefe two ventricles, are four prominences : The two anterior are called (bccaufe of their inner texture) Corpo- ra Striata ; the other two are . named Thala- mi Nervoruni Opticorum. Beyond thefe, are two more procefles, called Nates: And under them, nearer the Cerebellum, two called Teftes. Above the Nateis, is fituated the Gland ula Pi- nealis, famous for beingfuppofed by Des Cartes, the feat of the fonl. And upon the Thalami Nervorum Opticorum, are anumber of blood- veiTels, glands, andlymphasduds, called Plexus Choroides. Under tbe beginning of the For- nex, is a fmall Foramv^n called Foramen ad Radices Fornicis, or Iter ad Infundibulum. And under the middle of che Fornix, one cal- led Foramen Pofterius, which is covered with a valve named Membrana or Valvula Majors and the fpace under the two anterior ventricles between the Foramina and the Cerebellum, is the third ventricle. Cerebellum, is fituated under the fe« cond procefs of the Dura Mater. By dividing this part of the brain length-ways, we difcover more plainly the fourth ventricle, v/hofe ex* tremity is called Calamus Scriptorius ; here alfo appear two medullary bgdies called Pe- R 2 dunculi, 244 Of ^^^ Medulla Oblongata. I dunculi, which are the bafis of the Cerebel- Jum. The medullary part in the Cerebellum, though it is inmoll, as in the Cerebrum, yet is of a different fhape, being branched out like a plant. The fubftance of the brain is diftinguiihed into outer and inner; the former is called Cor- ticalis, Cinerea, or Glandulofa, the latter Medul- lariSj Alba, or Nervea. Medulla Oblongata, is a medulla- ry produ6lion from the under part of the Cere- brum and Cerebellum: It firft appears in two bodies from the anterior part of the pofterior lobes of the Cerebrum, called Crura Medulla Oblongatae. The union of thefe Crura between the Cerebrum and Cerebellum, is called Ifth- nius ; and immediately beyond this, is an emi- nence, named Procefius Annularis. Medulla Spinalis, is a produdlion of the Medulla Oblongata through the great Foramen of the fcull, and through the channel of the fpine : It enlarges about the laft Verte- brae of the back, and firfl of the neck, where the large nerves are given off to the arms; it again enlarges in the loins, where the crural nerves begin ; and the lower end of it witli thofe and other nerves, is called from its re- ferhblance Cauda Equina. The coats of this part are the fame with thofe of the brain; but the membrane here, which is analogous 8 to Of the Medulla Sp'tnaUs. 245 analagaus to the Dura Mater, is thinner and more conne(5led to the bones, and the Tunica Arachnoides more confpicuous. Wounds in the Cerebrum, though very dangerous, arc not mortal; but in the Cere- bellum and Medulla Oblongata, they eaufe fudden death \ and in the Medulla Spinalis, lofs of fenfe in all the parts which receive nerves from below the wound. In perfons that have died lethargic, I have always found- the brain full of. water \ and in children the brain is always very foft and moid. In a man that died of an apo- pkxy I found all the vefTels of the brain immo- derately diilended with blood, and the ven- tricles and the fubftance of the brain full of lymph, and the Pia Mater very Jmuch thick- ened, and adhering fo very loofely, that the greatefl: part of it ,wa? -feparat^d without break- I HAVE twice feeri-: in the Gerebruni a fchir- rous tumour as. large as a pullet's egg ; and in another body, . impofthumations which, pof- felTed near two thirds of the whole Cerebrum. And in a perfon that died with a Gutta Serena, I found all the ventricles of the brain fall of lymph j and the Thalami Nervorum Optico- rum and the optick nerves., e'er they went out of the fcull, made flat with the preiTure. And in an old man I found the right optick nerve wafted, and black, R3 CHAP 1^6 CHAP. XV. Of the nerves. ** y-fRoM the medullary part of the Cere- J^ " brum, Cerebellum, and Medulla Spi- " nalis, a vafl number of fmall medullary white " fibres are fent out, which, at their firfl: egrefs, " feem eafily to feparate, but as they pafs for- *' ward are fomewhat more, but ftill loofely " conneded, by the coat which they obtain '' from the Pia Mater, and at lafl piercing the ^' DuraMater, are flraitly braced by that mem- " brane which covers them in their progrefs;^ " whence they become white, firm, flrong f cords, and are fo, well known by the name " of nerves. To thefe coats an infinite- num- " Iper of v^fTels, both arteries and veins are " diflributed) fo that after a nice, lucky injec-^ *' tion the whole cord is tinged with the colour *' o|^ the injedted liquor •, but when the fibrils " are examined, even with the beft microfcope, *' they appear only like fo many fmall diftinft ^' threads running parallel, without any cavity ^^ obfervable in them, though fome incautious '' obfervers, millaking the cut orifices of the ^^ arterious and venous vefTels, juft now men- " tioned., for nervous tubes, have affirmed •"* their cavities to be vifible. The^erves, which "if Of the nerves. \ ' 247 " if all joined, hardly make a cord of an inch . " dianneter, would feem from their exert- '' ing themfelves every where, to be diftri- ^' buted to each, even the fmalleft part of *' the body. In their courfe to the places for *' which they are deftined they generally run *' as ftrait^ as the part over which they are to ** pafs, and their own fafety from external *' injuries will allow, fending off their branches *^ at very acute angles, and confequently run- '* ning more parallel than the blood vefTels. *^ Their diftribution is feldom different in the ** oppofite fides of the fame fubjedt, nor in- ^' deed in any two fubjecls is there conli- *' derable variety found. Frequently nerves ^' which come out diftindl or feparate, after- " wards conjoin into one Fafciculus, under the *' fame common covering; and though the *' nervous fibrils probably do not communi- " cate, (the Reafon of which opinion fliall *' immediately be given) yet becaufe the coats, " at the conjoined part are common, and thefe " ftrong coats may have great effeds on the " foft pulpy nerves, it is evident all fuch will ^' have a conliderable fympathy with one ano= ^^ ther, whereof feveral examples in pradlice ^"^ iliallbeinftancedwhenthe particular nerves " are defcribed. In fome pai'ts where there ''' are fuch conjundions, the bulk of the nerves f feems much increafed, and thefe knotty R 4 " oval 248 Of the nerves. • " oval bodies, called by Falloppius CorpofaO- "^ livaria, and generally now named ganglions, "^ are formed j the coats of thefe knots are '^ flronger, thicker, and more mufcular, than "the whole nerves which enter into them " would feem to conftitute, while the nervous " fibrils pafs through without any great al- " teration or change. I do not think any au- " thor has yet made a probable conjedlure of " the ufe or defign of thefe ganglions, whe- '' ther they imagine them Corcula Expellen- " tia, refervoires, or elaboratories , neither '' can I give an account of their ufe the leail ^^ fatisfadory to my felf. " From undeniable evident experiments, " all anatomiils are now convinced that to the " nerves we owe all our fenfation and motion^ ^' of which they are the proper organs -, and ^' the fenfations in the minutell parts being " very diflinft, therefore the inflruments of " fuch fenfations muft have diflindt origins ^' and courfe to each part. Though all are a- " greed as to the efFe6t, yet a hot difpute has ^' arofe about the manner how it is produced, " viz. whether fenfation and motion are occa- *' fioned by a vibration communicated to the " nerves, v/hich thefe gentlemen fuppofe en- " tirely folid and tenfe, or by a liquid con- *' tained and moved in them. The lafl of thefe >^ opinions I rather incline to for thefe reafons, " b^caufe Of the nerves. 249 " becaufe the nerves proceeding from the brain *' bear a great analogy to the excretory duds '' of other glands. Then they are far from be- " ing ftretched and tenfe in order to vibrate : <' And what brings the exiftenceof a liquid in ^' their cavities next to a demonftration, is the " experiment iirft made by Bellini, and related '^ by Bohn and Pitcairn, which I have often ¥ done with exa6l good fuccefs; it is this: " After opening the Thorax of a living dog, " catch hold of and comprefs the phrenick '' nerve, immediately the diaphragm ceafes to " a6l *, remove the comprefling force, that mu- '' fcle again contradls ; gripe the nerve with '' one hand fome way above the diaphragm, " that Septum is unadive ; then with the other *' hand ftrip down the nerve from the firfl " hand to the diaphragm, this mufcle again " contracts ; after once or twice having ftrip- " ped the nerve thus down, or exhauited the " liquid contained in it, the mufcle no more " ads, fqueeze as you v/ill, till the firil hand is ^' taken away or removed higher, and the " nerve ftripped, i. e. the liquids in the fuperior " part of the nerve have free accefs to the " diaphragm, or are forced down to it, when '' it again will move. Now if this liquid Ihould ■" be^ granted us, lam afraid we lliall be frill ^' as much at a lofs to account for fenfation ^^ and motion as ever, and therefore all I fhall '' afTume 2 JO. Oj the nerves. " afTume is what is founded on experiments, " that thefe two adtions do depend on the * *' nerves ; that fenfation^ are pleafant as long " as the nerves are only gently affeded with- '* out any violence offered them ; but as foon *' as any force applied goes beyond this, and '' threatens a folution of union, it creates that *' uneafy fenfation pain; that the nerves, *' their fource, or their coats being vitiated **• either convulfion or palfy of the mufeles ** may enfue. *' The nerves are diftinguilhed into two " claiTes, of the Encephalon and Medulla Spi- *' nalis; of the firfl there are generally ten pair " reckoned, of the laft thirty. I fhall defcribe *' the nerves in the fame order in which they *' are generally ranked, though it is not pof- " fible to profecute the diffedtion of them af- *' ter the fame manner ; but to fupply this, " I fhall mentipn alfo the order wherein they " may be all demonftrated on one fubjedl. *' "When I aflign the origin of any nerve from ♦' any particular part, I defire it may be un- *' derftood of that part of tlie furface of the ^* Medulla where the nerve firft appears ; for *' by this method v/e will fhun any difpute " with thofe authors who trace their rife too " minutely, and perhaps be lefs liable to mif- " take or to deceive our readers. Nor fhall I " be over anxious about the terminations of « the Of the nerves. iji <' the Minimas Fibrillse, fmce it is not poili- ** ble to trace them Ad Ultimos Fines , nor *' do I think very neceflary for explaining any *' Phaenomena, while very often in a multipli- " city of words, the whole defcription comes * *' to be obfcure or unintelligible. ''Of the ten pair proceeding from the En- *' cephalon, the firfl is the olfadory, which in <' brutes, juftly enough, has the nameof Pro- " ceflfus Mammillares beftowed on them, be- " ing large and hollow, and are indeed evi- *' dently the two anterior ventricles of the " brain produced; which llrudure, and the «' lymph conflantly found in them, induced '' the antients to believe that they ferved as " emundories to convey the fuperabundant *' Mucus from the cold moift brain to the nofe; «' but in man they are fmall, long, and with- '' out any cavity, rifmg from that part of the " brain where the carotid arteries are about " to enter, and running under the ancerior '' lobes of the brain become a little krger, till '' they reach the Os Cribriforme, into the Fo- *' ramina, of which the fmal filaments infinuate *' themfelves, as upon gently pulling thofe *' nerves or after having cut them very near the '' bone is evident, and are immediately fpread *' on theMembrana Narilim. Their tender flruc* *' ture and fudden expanfion on fuch a large *' furface, make it impoflible to trace them on '' the 2yi Of the nerves. " the membrane of the noftrils, which has *-' given fome handle to feveral authors to de- " ny them theflrudlure or ufe to nerves. ^^ The fecond are the optick, which arife fm- ^'^ gle from the Thalami Nervorum Opticorum, '' and then uniting at the fore part of the Cel- *' la Turcica, they feem to be pretty much **^ blended; afterwards they divide, andrun- *' ning obliquely forwards, pafs out at their *' proper hole of the fphenoide bone, and en- *' ter the globe of the eye to be expanded into *' the Membrana Retina. From this conjundi- *' on of thefe nerves, authors generally endea- " vour to account for our feeing objedts fmgle, *' whereas we have reafon to believe fifhes, " the chameleon, &c. whofe optick nerves *' fimply crofs one another without any fuch •" union, do fee obje6ts alfo fingle, fince they *^ fo exadly rulli on their prey ; whereas if " thofe authors aflertions were true, they *' would oftener catch at the fhadow than the " fubftance. The blood vefTels running through ^^ the middle of thefe nerves, and the ramifi- ^' cations of the Retina are very obfervable, **^ whence we may deduce the reafon of Picar d's *' experiment of fuch objedls as fall on the^en- '^ try of the optick nerve being loll to us, and '^^ hence alfo an account may be given of an ^' Amaurofis or Gutta Serena. The Of the nerves. . 2<5 "The third pair of nerves firft appear at " the anterior part of the ProcefTus Annularis, " and going out at the Foramen Lacerum. are " diflributed to the globe of the eye y Mufcu- *' lus Redliis Fallopii, AttoUens, Adducens, *' Deprimens, and Obliquus Minor; there- " fore this pair has juflly got the name of '' Motores Oculi. " The fourth pair, which are the fmalleftof " any, derive their origins from the anterior la- " teral part of the ProcefTus Annularis, andgo " out at the Foramina Lacera to he entirely " fpent on the Mufculi Trochleares, or Obliqui " Majores Oculorum, to which mufcles chiefly " the rotatory motion of the eyes in ogling «<= and the advance of the eyes forward in fta- *' ring, and fury, is ov/ing ; for which reafon " anatomiils have called thefe nerves Pathe- *' tici. " The fifth pair rife from the fides of theannu- ^' lar procefs, and after piercing the Dura Mater " divide into three branches; the firft of which is " the Opthalmick, vi^hichas it is about to enter " the orbit by the Foramen Lacerum, fends off " a fmall twig that aifiils in the formanon of " the intercoflal, and then the nerve is difcri- " buted to the Glandula Lacrymalis, fat, mem- " branes, and Palpebrse of the eye, while it ^' fends one con,fiderab]e branch through the ^' Orbited Internus Anterior hole to be loft in " the 2 54 Of the nerves. " the Membrana Narium, and a fecond paffes *' the Foramen and Supercilia to fupply the *' mufcles and teguments of the forehead. ♦' Hence we eafily difcover what part is affed- *' ed in that painful difeafe the megrim, when *« the eye-ball and forehead are racked, and i " ** fuch a heat is felt within the nofe : Hence alfo *' we may learn how the mufcles of refpiration *' come to be fo much affeAed on the applica- . *' tion of any acrid irritating fubftance to the i *' Membrana Narium, as to produce that vio- ** lent convulfive motion, fneezing. The fe- ** cond branch of the fifth pair, which may be '' called Maxillaris Superior, paffes out through *' the Foramen Rotundum Offis Sphenoidis, *' and immediately gives nerves to the fat un- *' der the crotaphyte mufcle, and to the pa- " late. Sinus Sphenoidalis and noftrils. The *' remaining trunk infmuating it felf into the *' channel on the top of the Antrum Highmo- *' rianum, to which cavity and to the teeth '' 01 the upper jaw it gives fmall twigs, at laft *' comes out at the Orbiter Externus hole, and *' is bent on the Mufculus Orbicularis Palpebra- " run, nofe and upper lip, where fome branches of the feventh pair feem to unite themfelves to the twigs of this. The third branch or Maxillaris Inferior goes out at the Foramen Ovale, or fourth hole of the wedg-like bone, and foon fplitting into a great many bran- " ches «c Of the nerves. ^5f " ches, is diftributed to the Mufculus Crota- «' phites, Mafleter, Pterygoides, Digaftricus, " Buccinator, Mylohyoideus, Geiniohyoideus, «' Genio-glofTus and Bafio-glofliis , Glandula " Sublingualis, Maxillaris Inferior, and Pare- " tis, to the external ear where it feems to ^' join the Portio Dura ; to the fubftance of ** the tongue in which it is pretty much con- ^' founded with the ninth pair: From the root " of this laft branch the Chorda Timpani is *' refleded. The laft ramification of this branch *' which I fhall mention, is that which enters " into the canal of the lower jaw, furnifhes the " teeth there, and comes out at the chin, on " which and the lower lip it is beftowedj at *' this place it is again conjoined to the feventh " pair. From this fhort fketch of the large " fifth pair of nerves, and by obferving feveral " Ph^enomena which happen to thofe parts to '« which they are diftributed, we might have *' a much farther confirmation of the general '^ dodrine of nerves delivered, and fee, at *' leaft, the way pathed to a rational account " of thefe Ph^enomena, for reafoning of which " we fhould not otherwife have the leaft ground. " We can, for example, from the Chorda Tym- " pani and the nerves of the teeth being de- " rived from the fame common trunk, under- *' ftand how the found of any vibrating body ^ held between our teeth is fenfible to us, ^' when 1^6 Of the nerves. " when another cannot poflibly hear the leaft *' on't. By the like rule we know why in a vi- • «' olent tooth-ach the mufcles of the face are *' fometimes convulfed; nor ihall we be fur- *^ prized to hear one plagued with the ach in *' his upper teeth, complain of a gnawing pain *' deep feated in the bones of his face, or to *^ fee his eye-lids much fwelled, or the tears '*^ trickling down in great abundance; whereas *' the lower teeth aching, the ear is pained, " and the Saliva flows in great quantities* We *' may have fome diftant views of fome foiin- " dation in reafon for the cure of the tooth-ach, *' by flrong compreflion of the chin, or by *' applying blifters behind the ears, or by burn- *' ing behind or on the ear. Among a great *' many inflances of the good effedl of the ac- " tual cautery in fuch a cafe, I fhall give one *' which feems to me remarkable. L M. was *' feized with the tooth-ach, a convulfion of " that whole fide of his face followed whenever '^ the pain became acute, or he attempted '' to fpeak \ after he had undergone blooding, *' purging, falivation, fetons, &c. without any *' benefit, he was cured by applying a fmall " cauterifing iron to the Antihelix. ''The fixth pair of nerves arifing from " the fore part of the Corpora Pyramidalia, *' after piercing through the Dura Mater, give *' off a branch, which joined with the refle6l- " ed Of the nerves. 257 «' ed twig of the the ophthalmick branch of " the fifth pair, forms the original of the irt- *' tercoftai, pafTes through the Foramen Lace- '' rum to be fpent eritirely on the Mufculus *' Abdu6lor Oculi, fuppbfing this nerve to *' fupply ever fo little lefs than a due propor- *' tion of Liquidum Nervofum, an involuntary *' Strabifmus will be occafioned. "Though the fifth and fixth pair of " nerves form entirely the beginning of the " intercoflal before it goes out of the fcull, yet *' becaufe feveral other nerves contribute to- '' wards the formation of its trunk before it *' fends off any branches, I Ihall fuperfede the " defcription of it till the original nerves are *•' fpoke to. "The feventh pair appears coming out " from the fide of the root of the annular " procefs, and entering the Meatus Audito- *' rius Internus, and immediately dividing one " part, foon lofes its firm coats, and is ex- " panded on the inmofl: Camera of the ear, " while the other pafling through the Aquas- *' du6tus Fallopii comes out of the fcull in- " volved in all its coats between the flyloide " and maftoide procefles; whence we fee the '' reafon of the firft being named Portio Mol- " lis, and the other Dura : This laft after its' *' exit fupplies the Mufculi Obliqui Capitis -. ,- ^[ StylohyoideijStyloglofiiandStylopharyngei, S '* and 2^8 Of the nerves. '*• and x^latylma Myoides, on which and to the '^ fkin of the neck , a great number of its " fmall filaments run, which are fometimes " cut in opening the jugular vein, whence " pain at firfl, and a little numbnefs after- '' wards. The fuperior branches of it fupply " the parotid gland, external ear and whole '* fide of the face as far forwards as the chin. " It is faid to communicate thrice with the " fifth pair, and twice with the fecond verte- " bral. Whether may not we hence fee fomc *' reafon why the' head is fo foon moved by '' the imprefTion of found on our ear? '^ T H E eighth pair of nerves derive their ^' origin from the fide of the bafis of the Cor- " pora Oiivari^, where their loofe filamentous " texture is very confpicuous 5 then running '' to the hole common to the Ofia Temporum ^' and Occipitis, they are there joined by the " Accefibrius Willifii, which has its beginning *' from the two or three fuperior nerves of *« the Medulla Spinalis, and mounts upwards " thither, to pafs out with the eighth pair, at " that common Foramen jufi: now mentioned: '' Very foon after they, wrapped up in the fame *' coat, have got out of the Cranium, the Ac- *^ cefibrius feparates from its companion, and " after pafling through the middle of the " Mufculus Maflioideus is lofl: in the Mufculus '' Trapezius andRhomboides Scapula. While I '' the Of the nerves. 259 " the large trunk, which from the great num- *' ber of branches it fends off Obtains the name " of Vagus, runs ftrait down the neck, near " the carotid artery, in its courfe giving feveral " branches to the Larynx: When entered the *' Thorax it fplits into two ^ the anterior ferves " the Pericardium, fends branches to join with *' thofe of the intercoftal that go to the heart, " and then on the right fide turns round " the fubclavian, and on the left round the " great curvature of the Aorta to mount again " upwards at the fide of the (Efophagus to be " lofbin the Larynx. This recurrent branch it ** is that we areearneftly cautioned to avoid in " Bronchotomie, though by reafon of its deep *' fituation we are in no hazard of it. If both " thefe nerves were cut, it is probable the voice " would not be entirely loft as long as the fli- *' perior branches fcill fupply the Larynx. The " pofterior branch of the eighth pair goes a- ^' long with the CEfophagus, and fupplies the *' lungs, the Gula and ftomach very plentiful- " ly: And as all the nerves beftovved on this " Vifcus enter at the fuperior orifice of it, the " fenfation here muft be very acute ; whence " Helmont imagined the mouth of the ftomach " to be the feat of the foul. What remains of " this Par Vagum is adjoined to the intercof- " tal immediately below the diaphragm. S 2 " The z6o Of the nerves. ''The ninth pair appears firft at the inferi- *• or part of the Corpora Pyramidalia , and ' march out at their proper holes of the Occi- ' pitis, and after fending off fomc nerves to ' the Glandula Thyroidea, and Mufculi Ster- ' no-Hyoidei, and Sterno-Thyroidei, are lofl: ' in the fubttance of the tongue. Authors ' have difputed whether this ninth or the fifth ' is the gaflatory nerve; the old opinion in fa- ' vour of the ninth is to me mod probable, be- •' caufe the fifth is no where elfe employed as •' an organ of fenfation, becaufe the ninth feems ■' to penetrate the fubflance of the tongue more, ^' while the fifth is fpent on the mufcles. " The tenth pair comes out from the begin- " ning of the Medulla Spinalis betwixt the Os *' Occipitis and firft Vertebra Colli, and is all, '' except what goes to the ganglion of the in- *' tercoftal, fpent on the Mufculi Obliqui, and " Extenfores Capitis. "The only nerves proceeding from the '^ Encephalon not defcribed, are the refleded " branches of the fifth and fixth, which indeed «^ are fo fmall and pappy, and hid by the ca- '' rotid artery as they go out with it in its '^ crooked canal, as not to be eafily traced, but " whenever they have efcaped from the Os '' Petrofum they are joined by branches from " the eighth, ninth, tenth; and firft and fecond " fpinal, and the largeft ganglion of the body "is Of the nerves. 261 " is formed, from which the nerve named now " intercoftal goes out to defcend down the " neck with the carotid, fupplying in itscourfe " the Mufculi Flexores of the head and neck, *^ and communicating with the cervical nerves. " As the intercoftalis about to enter the Tho- " rax, it again forms a ganglion, from which " nerves to the Trachea Arteria and the *' heart are fupplied, which join with the bran- " ches of the eighth, andpafs between the two " large arteries and auricles to the fubftance ^' of that mufcle. Now let any one confider the " egrefs of the intercoftal, and clofe courfe of " it and the eighth with the carotid artery, " and this manner of entry of the cardiac nerves, " furely the alternate conftridion and relaxa- *' tion of the heart will appear neceflarily de- *' pending on the difpofition of thefe organs ^' of motion, the nerves. The intercoftal after ^^ this runs down on the fide of the Vertebrae " Thoracis, having additional nerves conftant- *^ ly fent to it from between thefe Vertebra, ^' till it pafs through its own proper hole of " the diaphragm -J whence it again forms ano- y^ ther ganglion clofe by the Glandulas Renales, '^ into which the eighth pair enter. Fromfdcha y^ knot on each fide, the nerves of the guts, liver, *^ fpleen. Pancreas and kidneys are derived, *' nay the extremity of this nerve is {tnx. dawn ^'' to the Pelvis to fupply the parts there. Hence S 3 -the i6z Of the nerves. " the great fympathy of thefe parts may be ea- " fily deduced, and a reafon may be given of " the violent vomiting that commonly attends " a Nephritis, and of the belching cholicks " and ftomach-achs, which often enfue on the " obilrudions of the Menftrua. "Before I proceed to the fpinal nerves, " I fhall fet down the order in which thefe '' nerves already defcribed, are to be diffeded " in order to demonftrate them all in one fub- " Jed, but to them mufl afTume the three firft " cervical nerves, the reafon of which will be *' evident afterwards. " Portio Dura feptimi, Frontalis quinti, " Facialis quinti, Mentalis quinti. Spinalis fe- '' cundus. Spinalis primus, Olfadorius, Oph- " thalmicus quinti, Motorius Oculi, Patheti- " cus fextus, Opticus, Maxillaris inferior quin- " ti, Maxillaris fuperior quinti, Accefibrius " Willifii, nonus, decimus, odlavus Intercof- " talis, Portio Pvlollis feptimi. "The thirty pair of nerves proceeding " from the Medulla Spinalis, are generally " divided into four fpecies, of the neck feven, ''• of the back twelve, of the loins five, .ind of " the Os Sacrum fix. Now as the Medulla " Spinalis has none of thefe inequalities fo ob- " fervable on the Medulla Oblongata Ence- " phaii, the rife of the nerves is not fo accu- ^' ratelj Of the nerves. 263 " rately defcribed, being only determined by " the bones through which they pafs. "The firfl cervical goes out between the " firfl and fecond Vertebra, and, after fending " off branches that communicate with the tenth *' and fecond Vertebrale, is fpent on the Muf- *' cuius Flexus Colli, Splenius, Complexus, and *' teguments of the Occipitis. "The fecond cervical communicates with " the ninth, and with the firft and third of the " neck, and then is diflributed to the Tegu- '^ ments of the neck and fide of the head, and " to the Glandula Parotis and external ear, " where it joins with the Portio Dura. " The third of the neck pafies out be- " tween the third and fourth Vertebra, foon *' communicating with the fecond, and fend- *' ing down a large branch, winch being joined " by another from the fourth forms the phre- " nick nerve that runs along the Pericardium '* to be loft in the diaphragm. In this courfe " the right phrenick is obliged to make afm.ul *' turn round that part of the Pericardiam *' which covers the Apex of the heart. Hence " it is, that fuch as have ftrong palpitations " of the heart, feel a pungent acute pain im« *' mediately above the right orifice of the fto- " mach. The other branches of this third cer- " vical are diftributed to the Mufculus Trape- ^^ zius and Deltoides, and to the teguments S 4 "on 264 Of the nerves. " on the top of the (houlder •, which, with the '' defcription of the eighth pair, leads us evi- '^ dently to the reafons of the divine Hippo- *' crates's obfervation, t^hat an inflammation " of the liver is generally attended with a " hickup^ and a fuppuration of that Vifcus with '' a violent pain on the top of the ihoulder. '' However we are not hence to conclude fo " generally as I have obferved phyficians fre- *' quentlydo, that if the Hypochondria are af- " fedled, and this pain of the fhoulder is felt, " therefore the liver is fuppurated, for any *' other caufe ftimulating or flretching the *' nerves, fuch as inflammation, wounds, fchir- " rhous or fteatomatous tumors, &c. may pro- *' duce the fame effedl. , "The fourth cervical, after fending off " that branch which joins with the third to *' form the phrenick, runs flrait to the Axilla, *' where it meets with the fifth, fixth and fe- " venth cervicals, and firfl: dorfal that efcape in *' the interftices of the Mufculi Scaleni ; and all *' of them are fo often conjoined and blended, *' after they have given off nerves to the mu- " fcles of the neck, 5capula, arm, and Tho- " rax, and to the teguments, that when the " feveral ramifications go off in the Axilla to " the different parts of the fuperior extremity, " 'tis impoflible to determine which of them ^^ the branches belong to. The confiderable " branches Of the nerves. %6j '.' branches into which they are divided are *' fix; thefe I fhall prefume to give proper di- ^' flinguifhing names to, by which the defcrip- *' tipn will be lefs confufed, and the young " anatomift's memory better afliHed to retain " what is fp difficult to reprefent in words, " I. CuTANEUS runs down the forepart *^ of the arm, and ferves the teguments, as " far as thje palm of the hand and fingers. f^ 2. Muscu|:.o-CuTANEU§, or Perfo- ^' rans CafTerii pafles through the Mufculus " Coraco-Brachialis , and after fupplying the *' Biceps and Brachiaeus Internus, is fpent on " the teguments of the back of the Cubitus *' and hand. *' 3. MuscuLARis, that runs down the " fore part of the arm to be loft in the Muf- '' culi Flexores Carpi, Digitorum, &-c. ^' 4. U L N A R I s, which fupplies the Exten- " fores Cubiti, and teguments of the elbow, " and then paffing through the finuofity at " the back of the external condyle of the " Humerus, runs along the Ulna, where it " gives twigs to the teguments and neighbour- " ing mufcles, at length is loft in the back of " the hand, Mufculi InteroiTei and Lunibri- *« cajes in the little finger, and fide of the ring- " finger next to this. The courfe of this nerve *' is fufficiently felt when we lean on our elbow, " by 2 66 Of the nerves. " by the infenfibility and prickling pain in the " parts to which it is diilributed. " 5. R A D I A L I s , goes down the fore-part *^ of the arm near the Radius, bellowing bran- '' ches in its progrefs on the circumjacent muf- *^ cles, and at the Ligamentum Annulare Car- " pi fplitting, is fent to the thumb, fore-finger, *' middle finger, an half of the ring finger, and *' to the back of the hand. "6. Articularis runs almofl round *' the top of the Os Humeri, and ferves the ^^ Mufculi Extenfores Cubiti, Retradlores and " Elevatores Humeri. *' By a ftrong and continued prefTure on *' thefe nerves, by crutches, or any fuch hard '^ fubftance a palfy and atrophy of the arm *' may be occafioned. "The twelve dorfal nerves all communi-^ ^' cate with one another as foon as they make " their way out betwixt the Vertebra, each of *' them gives a poflerior branch to the Muf^ **' culi Eredtores Trunci Corporis i the firfl, ^' after having fent off the brachial nerve, al- " ready defcribed, is after the fame manner, *' with the fucceeding eight, bellowed on the " Pleura and intercollal mufcles , the tenth ^^ and eleventh are moil of them fent to the ^' abdominal mufcles, the twelfth communi- ^' cates with the firft lumbar, and is bellowed '' on Of the nerves. 167 ^' on the Mufculus Quadratus Lumbalis and ^' ILiacus Internus. "The fifth lumbar alfo communicates and ^' gives poilerior branches *, the firfl fends fe- " veral branches to the abdominal mufcles^ " and Pfoas and Iliacus, while others go from " it to the teguments and mufcles on the fu- " perior and anterior part of the thigh, and " the main trunk of it is loft in the crural. The " fecond pafTes through the Pfoas mufcle, and ^' is diftributed much as the former. The, third ^' is loft in the Mufculus Pedineus. Branches ^' proceeding from the firft, fecond and third '' make up one trunk, which runs along the " anterior part of the Pelvis, and flipping " through a fmall finuofity in the anterior" " part of the Foramen Magnum Offis Ifchii, ^' is fpent in the Mufculus Triceps. This " nerve is commonly known by the name " of Obturator, or pofterior crural nerve. " By the union of branches from the firft, fe-^ " cond, third, and fourth lumbar nerves, the ^' anterior crural nerve is formed, which run- " ning along the Mufculus Pfoas, efcapes with ^' the large blood-veffels out of the Abdomen " below the tendinous arcade of its mufcles, ^' and is diftributed to the mufcles and tegu- *' ments on the fore part of the thigh : One " branch of this crural nerve accompanies the ^^ Vena Saphsna as far as the ancle. Now let ^' us i6S Of /he nnves. I I BOI—^— . I J Ml II III! — M— — — U I '' US imagia'^ the ricaation of the kidney upon, *' and the courfe of the Ureter over thefe nerves, *' and we Ihall not be furprized, that in a Ne- *' phritis, the trunk of the body cannot be " raifed eredl without great pain; that the thigh *' lofes of its fenfibility, and that it is drawn *' forwards. The remainder of the fourth and '^ the fifth lumbar nerves join with the firft, fe- " cond, and third that proceed from the Os Sa- ^' crum: Thefe five,when united, conftitute the " largell nerve of the body, fo well knov^n by *' the name of the fciatic, or ifchiatic nerve, *' which feems to be bigger, in proportion to *' the part for the ufe of which it is, than the *' nerves of any other part are; the defign of *^ which may be to afford fufEcient ftrength *' to the mufcles of the lower extremity, for *' exerting a force fuperior to what is requi- ^' red in any other part of the body. When *' this nerve is any way obftrucled, we fee *' how unable we are to fupport our felves, or ** to walk. The fciatic nerve then goes out *' at the large hollow, behind the great tuber- ^' cle of the Qs Ifchium, and pafling oyer the *' Quadrigemini mufcles, runs down the pofte- *' rior part of the thigh, giving off, ev€ry *' where as it goes, nerves to the teguments *' and mufcles of the the thigh and leg. At the \^ ham it fplits into two-, the fmaller mounts *.' over the Fibula, and ferving the M.ufcul^ I *^ Peronei Of the nerves, i6^ *' Peronei, Flexores Pedis, and Extenfores Di- " gitorum, is continued to the toes along the *' broad of the foot, while the larger trunk " finks under the Mufculi Gemelli, and then *' divides-, one is fpent on the mufcles at the " back of the leg and teguments, while the *^ other is continued by the inner anckle to " the foot, and then fub-dividesj one branch " is diflributed after the fame manner as the *' Ulnaris, and the other as the Radialis in the " hand. " The other nerves that come out of the *' Os Sacrum are fent to the organs of generati- " on, Mufculi Lcvatores Aniand Obturatores. " Thefe nerves of the Medulla Spinalis may ** all be diffeded and demonftrated in the *' fame order in which they are defcribed. '* The nerves feem, when examined with a microfcope, to be bundles offtreight fibres not communicating with one another: And I am inclined to think that every the minuteft nerve, terminating in any part, is a diftind: cord from its origin in the brain, or fpinal marrow ; or elfe I do not fee how they could produce di- ftind fenfations in every part ; and the diftind points of fenfation throughout the body are fo very numerous, that the whole body of nerves (which taken together would not make a cord of an inch diameter) muft be divided Into fuch a number, to afford one for every part that has 27 o Of the nerves. has a diftind fenfation, that furely fuch a nerve would be too fmall to be feen by the befl mi- crofcope. They all pafs in as diredl courfes to the places they ferve as is polTible, never fepa- rating nor joining with one another but at very acute angles, unlefs where they unite in thofe knots which are called ganglions, the ufe of which I do not pretend to know ^ they make what appears to be a communication of mofl of the nerves on the fame fide, but never join nerves of oppofite fides. That the nerves are inflruments of fenfa- tion, is clearly proved from experiments, but how they convey thofe fenfations to the brain, is matter of great difpu.te. The moll general opinion is that they are tubes to contain ani- mal fpirits, by whofe motions thefe fenfations are conveyed: And diligent enquiry has been made to difcover their cavities, but hitherto in vain ; and if each nerve is diftindl from its origin, as I have endeavoured to fhew, and too fmall to be the objedl of the beft microfcope, I do not fee how fuch cavities are like to be difcovered. However , I think the nerves may be tubes, and that a fluid, whofe cohefion is very little, and whofe parts are perhaps no finer than light, may move very freely in them. Thofe who deny animal fpirits in the nerves, fuppofe that the fenfation is conveyed by a vi- bration. To which it is objedled, that they are flack, Of the nerves, ly i flack, moifl, and furrounded with foft parts, and are therefore unfit for vibrations, as indeed they are for fuch as are made on the ftrings of a mu- fical inflrument ; but the minutefl vibrations, fuch as they cannot be without may be as fuf- ficientfor this end, as the impulfe of light upon the Retina, is for the fenfe of feeing. So that for ought that I can difcern, fenfations may be conveyed either , or both ways, though the advocates for each opinion, have chiefly infill- ed upon the improbabihty or impoffibility of the other opinion. TABLE ^7^ TABLE XIV. i. The' Pericardium covering the heart; 2. The lungs. The gland Thymus. The diaphragm* The liver. The ftomach. 7. The fmall guts. 2, 4- 5- 6. 7. TABLE ^^^51/ it 7:^ ^i^^c/7t ..rru/p i/Vl^/ ' '-4 / ^ j^^.xv: i73 TABLE XV. A, The liven B, The gall-bladden C, The Pancreas. D, The fplene. E, One of the renal glandsc F, F The kidneys. G, G, The ureters. H, The bladder of urine diftended. T, The Re6tum Ihteftinum. K, The Aorta. L, The Vena Cava. M, The four fpermatick VefTels, with the Ar- teria Mefenterica Inferior, raifed over a probe ; the middle one the Arteria Me- fenterica Inferior ; the two next the fper- matick arteries arifing from the Aorta ; the outmoft the fpermatick veins, the right ending in the Cava, the left In the left emulgent vein, TABLE i74 T B L E XVI. The vejfels of the brain filled with Wax. 1,1, The carotid artery, 2, 2, The cervical artery. 3.3, &c. The branches of the carotid artery which pafles between the lobes of the brain on the left fide. 4. 4, 4, The branches from the carotid artery which pafs between the hemifpheres of the brain. 5, 5, The branches from the cervical artery, which are bellowed upon the Cerebel- lum. 6. The fuperior longitudinal Sinus, 7. The inferior longitudinal Sinus, 8. The ftrait Sinus. 9. The lateral Sinus. 10. The circular Sinus. 1 1. A vein from the circular Sinus. 12. A Sinus at the upper edge of the Os Petrofum. 13. A Sinus at the lower edge of the Gs Petrofum. 14. The cervical Sinus, 3 TABLE 0^af''if7-y IksJOTI 275 TABLE XVII. Arteries filled with wax, 1. Part of the defcending Adrta. 2. Arteria Coeliacae 3. Mefenterica Superior. 4. Mefenterica Inferior, 5. Part of the communicant artery, 6. Shews one of the extream mefenteric arte^ ries, as it is diflributed round the inte- ftine. T i TABLE 176 TABLE XVIIL The Vena Port^e filled with wax. I, I, I. The extream branches of the Vena Ports in the mefentery. 2. The fingle trunk of the Vena Port as en- tering the liver. 3, 3, 3. The extream branches ofthe VenaPor- ts in the liver. . 4. One of the extream mefenteric veins^ TABLE (/-a^.^y? SvJtbcii Jful'-olls Jcu^. ^77 TABLE XIX. The veins of the liver. I. Part of the Vena Cava Afcendens. 2, 2, 2. The branches of the Cava taken out of the liver. T3 TABLE 278 TABLE XX- "The excretory duels and arteries of the liver. I. Ductus Hepaticus, with its branches, taken out of the liver. 3. The gall-bladder. 4. Du6lus Cyllicus. 5. Dudtus Communis Choledochus^ 6. Dudbus Pancreaticus. 7. The hepatic artery, which is given off from the fuperior mefenteric. 8. The hepatic artery, which is given off from the celiac. 9. Arteria Cyllica. TABLE ^^''^/^ 279 TABLE XXI. A PoLYPu s coughed up out of the lungs, which admirably fhews the manner of the Af- pera Arteria dividing in the lungs, commu- nicated to me by the late Dr. Oiiyer H(irfe- man. r 4 TABLE z8o TABLE XXII. Figure i _ Shews the circulation of the blood, in the tail of a greg, from Mr. Cooper. A, A^ A, Where the extreniities of the arteries and veins communicate. B, B, B, B, Several other communications. Figure 2 Shews the circulation of the blood, in the tail of a gudgeon. A, A, A, The large velTels. B, B, B, The e;stremities of arteries commu- nicating with the veins. C, C, Some fmall veflels whofe extremities could not be feen for the thickpefs of the tail. TABLE O'af.'irSa j?r4:^.xxii. ~Pi^^^u^^^FTrca7/. ^ /". If'uc/lir J'^ciil/'^ z8i TABLE XXIII. The cafe of Mrs. Stoneftreet of Lcwqs, Vid. page 170. TABLE 28i TABLE XXIV R E p R E s E N T s the cafc of Margaret White, mentioned page 171. A, The gut hanging out at the n^vel. *ABLE T^Bxxmr . CT'a^d Zc9 Z. T.A-liXXV (^-"a^^ '^<9l 283 TABLE XXV Represents the cafe of John Heyfliam^ who, the friday before Eafter in the year 1 72 1, by Over-ftraining himfelf at work, had a rupture of his intellines into his Scrotum, which could by no means be reduced. He was brought into St. Thomas's hofpital the mon 28y TABLE XXVII. The lower parts of a negroe, whofe Scro- tum was fwelled to this fize from a kick (the fpermatic vefTels being not at all thickened.) The greateft length was twenty feven inches, and the greateft horizontal circumference for- ty two inches. He was the late Mn Dicken- fon's patient in St. Thomas's hofpital ; the tu- mour was folid, without inflammation or pain^ but what parts were afFeded we could not learn, he not ftaying for the operation. At the dark place he could pull out his Penis, when the Scrotum was lifted up« BOOK 287 BOOK IV. CHAP. I. Of the urinary and genital parts of men^ together with the Glandula Renales. TH E urinary parts are the kidneys with their vefTeJs and bladder of urine. The kidneys of men are like thofe Tab. xv, of a hog, the two weigh about twelve ounces; ^- they are feated towards the upper part of the xxviL 5. loins upon the two lafl: ribs, the right under the liver, and a little lower than the other, and the left under the fpleen. Their ufe is tofepa- rate the urine from the blood, which is brought thither for that purpofe by the emulgent arte- ries; and what remains from the fecretion, is returned by the emulgent veins, while the urine fecreted is carried off through the ureters to the bladder. The ureters , are tubes about the bignefs Tab. xt. of goofe-quills ; and abQut a foot long, they ^\^' arife xxvii. 8. H. 288 Of the urinary and genital parts ^ &c. arife from the hollow fide of the kidneys, and end in the bladder near its neck, running "^^b. obliquely for the fpace of an inch between its xxvii. 21. ^ , . , -^ - . . , coats ; which manner or entering, is to them as valves. (Vid. page 191.) The beginning of the ureters in the kidneys, are the Tubuli tJrina- Tab. rii, which join from the Pelvis in each kid- Tab.' * ^^y- Between the Tubuli Urinarii, authors xxvii. 10. have remarked fmall Papillae i and the parts which diflinguifh themfelves by a clearer colour, they call Glandule. Tab. XV. The bladder of urine, is feated in a dupli- cature of the Peritoneum in the lower part of the Pelvis in the Abdomen -, its iliape is orbi- cular, and its coats are the fame with thofe of the guts, and other hollow hiufcles already de- Icribed ; viz. an external membranous, a mid- dle mufcular, which is tire Mufculus Detrufor Urinae, and an inner membranous coat, ex- ceeding fenfible, as is fully lliewn in the cafes of the flone and gravel. The ufe of this nice fenfe is, to make it capable of that uneafmefs which excites animals to exclude their water, wften the bladder is much extended. Some anatomifts not thinking how foon fluids taken into the flomach, and not retained there, by" being mixed with folids, may pafs into the blood, as the effects from drinking ftrong li- quors, or Laudanum, or drinking without eat- ing when we are hot, fufficiently lliew ^ and 6 alfo gemtalpartsof mevij &c. 289 alfo not confidering the lliortnefs of the courfe, from the itomaeh to the kidneys this way, to- gether with the fize of the emulgent arteries^ and the velocity of the blood in them, have imagined and affirmed, that there mull befome more immediate courfe from the ftomach or guts to the bladder, and not confidering either how fuch a courfe would have interrupted one great end in the animal oeconbmy, or that vefTels fit to fill the bladder fafler than the ureters, muil have been too large to be concealed. Glandul^e Renales are two glands Tab. xv. feated immediately above the kidneys, of no S; . certain figure, nor do we know their ufe ; but xxvii. 7. always paint and defcribe them with the urina- ry parts becaufe of their fituation: In a very young Foetus they are larger than the kidneys, and in an adult but a little larger than in a Foe- tus. They receive a great many fmall arteries, and return each of them one or two veins. In their infide is a fmall Sinus tindlured with a footy coloured liquor. Valsalva, in a difcourfe before the aca- demy of fciences at Bologna, has given an ac- count of a dud from thefe glands to the Epi- didymides in men, and the Ovaria in women, and undertook to prove that they are principal organs of generation, and promifed to publilli a treatife on this fubje(5l as foon as the cuts for it could be made •, but being fince dead, we U do ipo Of the urinary and do not yet know what was done towards it. Mr. Renby has fearched very carefully to dif- cover them, but in vain : However he has ob- ferved a fmall artery, which dividing, fends one branch into the renal gland, and the other into the Epididymis, which h^ thinks Valfalva has miilaken for a dudl. The genital parts of men are the Teftes and Penis, with their veffels, &c. The office of the Tefles, is to feparate the feed from the bloody they are feated in the Scrotum, and are faid to have four coats, two common, and two proper. The common are the outer fkin and a loofe membrane immedi- ately underneath, called Dartos. The firil of the proper, is the Proceflus Vaginalis; it is continued from the Peritoneum to the tefticle, which it inclofes with all its velTels, but is di- vided by a Septum, or an adhefion immedi- ately above the tellicle, fo that no liquor can pafs out of that part of this membrane which enclofes the fpermatic veffels into that which enclofes the tefticle. Large quantities of wa- ter are fometimes found in thefe cavities, which difeafe is feldom cured without opening the cavity where the water is contained, as in fi- nuous ulcers : But a true Hernia Aquofa is a rupture through the Peritoneum from the Ab- domen, which may be cured by a pundure ^ and in this cafe, as in the Hernia Inteftinalis^ 1 and genital parts ofmen^ &c. 291 and Omentalis, when once a cavity is ftretch- cd out, the infide of it is foon formed into a flrong membrane like that of a Cyflic tumour, and looks as if the Peritoneum it felf had been ftretched down thither, and thickened. (Vid. Mufculi Abdominis.) The other proper coat, is the Albuginea, which is very ftrong, im.- mediately inclofing the teflicles. The jiefci- cles of a rat may be unraveled into diftind T^^;. vefTels and the texture of the teflicles of all^^B,D, other animals appear to be the fame, but their velTels are too tender, or cohere too much to be fo feparated. The teflicles, receive each, one artery from Tab. xr, the Aorta, a little below the emulgents, which, -^^i^^ unlike all other arteries, arife fmall, and dilate xxvii. 12. in their progrefs, that the velocity of the blood may be fuiEciently abated for the fecretion of fo vifcid a fluid as the feed. The right tefli- fab. cle returns its vein into the Cava, and the left xxvii, 13, iiito the emulgent vein on the fame fide -, both becaufe it is the readieil courfe, and becaufe, as authors fay, this fpermatic vein v/ould have been obflrudled by the pulfe of the Aorta, if it had crofTed that vefTel to go to the Cava. A GENTLEMAN whom I cafcratcd, who trufled too much to his own refolution, and re- fufing to have any one prefent to hold him , except Mr. Geeke, who was my affiilant -, du- ring the operation, moved fo much, that the U 2 iigatufe x()r Of the urmary and li gature which tied all the veflels with the procefs together, flipt, and only tied the procefs over the ends of the velTels, which being perceived foon after the operation, I cut the ligature, and took oat the extravafated blood, and tied the artery alone, which gave but little pain, and it digefled off in a week's time, and the wound being afterwards ftitched, though the teflicle weighed a pound, it was perfedly well in five weeks -, which is in lefs time than the ligature often requires to be digefled off, when the procefs and all the veffels are tied together. However if this cafe is not fufficient to recom- mend doing this operation by tying the artery only, it may be fuffi: ient to recommend ex- traordinary care in doing of it the ufual way, for if the blood had found an eafy paffage into ■ the Abdomen , the patient might have bled to death without our knowledge. Tab. O N the upper part of the tefticles, are hard xxvii.i). ]3Q(;^;es called Epididymis which are evidently the beginnings of the VafaDeferentia. I have un- ravelled them backward, in fingle veffels, and then into more and fmaller, like the excretory veffels of other glands. T^b. Va sa Deferentia, are excretory duds xxvii. 18 ^Q carry the elaborated feed to the Veficul^ Se- minales. They pafs from the Epididymi of the tefticles, together with the blood-veffels, till they have entered the mufcles of the Ab- domen, genital parts of meUy &c. 293 domen, and then they pafs under the Perito- neum, diredly through the Pelvis, to the Ve- ficulas Seminales. VesicuLuE Semin ALES, are two bodies '^'^^\ that appear like veficles, they are isated under the bladder of urine, near its neck; they may be each of them eafily unravelled into one fm gle dud , which difcharge into the Urethra , by the fides of the Roftrum Galiinaginis, which TaS. is an eminence in the underfide of the Urethra, near the neck of the bladder. In thefe veficles or du6ls the feed is repofited againft the time of coition \ bqt in dogs there are no fuch veficles, therefore nature has contrived a large bulb in their Penis, which keeps them coupled, feem- ingly againft their inclinations, till the feed can arrive from the tefticles. The feed pafTes from thefe veficles in men, and even from the Vafa Deferentia, in time of coition, through the proftrate glands into the Urethra-, as in thofe animals that have no Veficulje Seminales, for when the duds into the Urethra are diftend- ed, that is the diredeft courfe from the Vafa Deferentia, as well as from the Veficul^e Se- minales. • . Prostat^e, are two glands, or rather Tab. one, about the fize of a nutmeg : They are feat- ^^vii. 20. ed between the Veficul^ Seminales and Penis, under the OfTa Pubis, almoft within the Pel- vis of the Abdomen. They feparate a lympid U 3 glutinous 94 Of the urinary and glutinous humour which is carried into the Ure- thra by feveral duds, which enter near thofe of the Proftatse •, this liquor feems to be de- fjgned to be mixed with the feed in the Ure- thra, in the time of coition, to make it flow more eafily. Penis, its fhape, fituation, and ufe, need no defcription. It begins with two bodies, named Crura, from the OfTa Ifchia, which u- nite under the OfTa Pubis, and are there flrongly connedled by a ligament. In its un- der part is a channel from the bladder, called Urethra, through which both the urine and feed pafs ; its fore-part is called Glans , the loofe fkin v/hich covers it, Prsputium, and the ilrait part of that fkin on the under fide, Froenum. The Urethra, is lined with a membrane filled with fmall glands, that feparate a Mucus, that defends it from the acrimony of the urine. Tliefe glands are largeft neareft the bladder. Mr. Cowper defcribes three large glands of the Urethra, which he difcovered \ two of which are feated on the fides of the Urethra, near the ends of the Crura Penis; to which he adds a third, lefs than the other, feated almoft in the Urethra, a little nearer the Glans than the for- mer. All thefe glands have excretory duds into the Urethra, The gemtal parts of men ^ &c. 295 The inner texture of the Penis is fponey, '^2^-. like the inner texture of the fpleen , or the ^^ ^* ends of the great bones. It is ufually diftin- guifhed into Corpus Cavernofum Penis, Glan- dis and Urethra? ; the firft of thefe makes part of the Glans, and is divided its whole length by a Septum \ the other two are compofed of fmaller cells, and are but one body. On the upper fide of the Penis, are two arteries, and one vein called Vena Iplius Penis. The arteries . are derived from the beginnings of the um- bilical arteries, which parts never dry up, and the vein runs back to the iliac veins. The Ve- na Ipfius Penis, being obftruded, the blood that comes by the arteries, diflends the cells of the whole Penis, and makes it erecft-, but to prevent any mifchief from this mechanifm, there are fmall collateral veins on the furface of the Penis, that carry back fome blood all the time the Penis is ere6b. By what power the Vena Ipfius Penis is obftruded to ered the Penis, I cannot conceive, unlefs fmall mufcular fibres conilrid it. Moil authors think the Mufculi Eredores Penis do it, by thruiling the Penis againfl the Os Pubis ; but they are not feated, as Mr. Cowper obferves, conveniently for fuch an office; befides, if a preflure from the low- er fide of the Penis is fufficient, an artificial preffare, which may be much greater, fhould, I think, produce the fame efred. When the U 4 matter 2 9^ Of the urinary and matter of a gonorrhea is fp virulent as to make ulcers in the Urethra, when thofe ulcers cica- trife they conftrid the Urethra, and make that difficulty in the waters pafling, which is vul- garly thought to proceed from caruncles. Tab. In the feed of men, and of many other xxviii. E. j^aJe animals, Lewenhoeck, by the help of microfcopes, difcovered an infinite number of animals like tadpoles , which he and others ^ fuppofe to be men in miniature, and that one of thefe being entered into an egg in one of the Ovaria, (See the next chapter.) conception is performed. But though fcarce any one, that has made due enquiry, has ever doubted of the exiftence of thefe animals, yet there are many . who obje61: againft this hypothefis ; and though I am inclined to think it true, yet I will endea- vour impartially, to lay down the principal ob- jeAions and anfwers, that the reader may judge for himfelf The firfl and ftrongeft objedipn, is raifed from the feveral inftances that have happened of mixed generation, where the ani- mal produced always appears to partake of both kinds, as in the common cafe of a mule, which is begot by an afs upon a mare j when according to that hypothefis, they exped: the animal produced from mixed generation, Ihould be entirely of the fame fpecies with the male animaU as the feeds of plants, whatever earth ^ they grovz in, always produce plants of the fame genital parts of men^ 8cc. zp/ fame kind; neverthelefs if we confider what influence womens fears or longings, frequently have upon their children in Utero, and how great a change caftration makes in the fhape of any animal, and that a lamb fuckled by a goap (if I have been rightly informed) grows hairy like a goat, we cannot then wonder if the mothers blood, to which the animal owes its nourilh- ment and encreafe, from the time of impreg- nation to the time of its birth, fhould be thought a fufficient caufe of refemblance be- tween thefe animals and their mothers. Another objection is , that nature fhould provide fuch a multiplicity of thefe animals, when fo few can ever be of ufe, an animal being to be generated of one only. To which it has been anfwered, that in all plants a vaft number of feeds are found, though a very few of the whole that are produced, fall into the earth, and produce plants ; and as in plants the greatefl part of their feeds are the food of animals, fo the great- eft part of the Animalculse, may as well live a time to enjqy their own exiilence, as any qther animal of as low an qrder. The laft pbjedion is their ihape, which I think, will appear to have no weight, when we confider how the eggs , of flies produce maggots, which grow up into pies; and the tadpole produced from the egg of a frog, grows into a form as different from a tadpole as the form of a man : And if thefe a,ni- I mals 298 Of the urmay^ &c. mals had produced fo few at a time, as that their young might have undergone this change in Utero, it is highly probable, that we fhoulcl not fo much as have fufpeded thefe analgous changes. Rut how the Animalcule themfelves are produced, is a difficult queftion, unlefs by e- quivocal generation, feeing none of them appear to be in a flate of encreafe, but all of a fize. In a boy that died of the flone, I found a double Ureter, each part being dilated to an inch diameter ; the Pelvis in each kidney to. twice its natural bignefs, and the Tubuli Uri- narii, each as large as the Pelvis. I N a man that had never been cut for the ftone > I found the Ureters dilated in fome places to four inches circumference, and in, others but little dilated, and a ftone that I found in the bladder was lefs than a nutmeg, which muft have fallen in feveral pieces, or both ureters could not have been dilated. From this, and other like obfervations , I think 4t appears that the prodigious fize to which the ureters are ufually extended, in people who are troubled with the ftone, is owing to fmall ftones which ftick at the entrance into the blad- der, until the obftruded urine which dilates the ureters, can force them into the bladder. I HAVE once met with a kidney almoft con- fumed , and lymphatics in a difeafed tefticle , as large as a crow-quil CHAP. ^99 CHAP. II. Of the gen'ual parts of women. TH E external parts, are the Mons Veneris, which is that rifmg of fat covered with hair above the Rima Magna upon the Os Pubis, the great doubling of the fkin on each fide the Rima called Labia, and within thefe a lefTer dou- Tab.xxi]?. bling named Nymphas. Thefe help to clofe up ^* the orifice of the Vagina : The Nymphs are Tab.xxix, ufually faid to ferve to defend the Labia from ^* the urine , but I do not fee how the Labia fland more in need of fuch a defence , than the Nymphge themfelves. Clitoris, is a fmall fpongy body bearing fome analogy to the Penis in men, but has no Urethra. It begins with two Crura from the OfTa Ifchia, which uniting under the OlTa Pubis, it proceeds to the upper part of the Nymphs, where it ends under a fmall doubling of fkin, called Preputium ; and the end which is thus Tab.xxix. covered is called Glans. This is faid to be the h , ^\ . r r r y r • • • • Tab.XXlX. chief feat or plealure in coition in women, as 4. the Glans is in men, •A LITTLE lower than this, juil within the Vagina, is the exit of the Meatus Urinarius. Vagina, is feated between the bladder of ^^^-^xiX' urine and the Intefcinum Re6tum. The texture of it is membranous, and its orifice is contra6t= ed 300 Of the genttal parts of women. edwithaSphinder (Vid. Mufc. Sphindler Va- ginae, ) but the farther part is capacious enough to contain the Penis without dilating, Near the beginning of the Vagina, immediately be- hind the orifice of the Meatus Uriharius , is conflantly found in children, a valve called Hymen, which looking towards the orifice of the Vagina, clofes it in the fame manner that the valves of the ventricles of the heart, clofe the entrance of the ventricles-, but as children grow up, and the Sphindler Vaginas grows more ufeful, this valve is proportionably fmal- ler, and in women very rarely to be found, only fome fmall parts appearing in the place of this valve called Carunculae Myrtiformes. There have been a few infiiances in which the edges of this growing together, it continu- ed unperforate, until it has been necefiary to make an incifion to let out the Menfes. The inner part of the Vagina is formed into Ru- gae, which are largeft in thofe who have not ufed copulation -, and leafl in thofe who have had many children. Under thefe Rug^ are fmall glands, whofe excretory du6bs are called Lacunae: Thefe glands feparate a rnucilaginous matter to lubricate the Vagina, efpecially in coition *, and are the feat of a Gonorrhea in this fex, as the glands in the Urethra are in the male. Uterus, • Of the genital parts of women. 301 Uterus, is feated ac the end of the Vagi- Tab.xxix^ na; it is about one inch thick, two broad, and large enough to contain the kernel of a hazel nut; but in women that have had children a little larger. Its orifice into the Vagina, is called Os Tinc^, from the refemblance it bears Tab.xxix. to a tench's mouth. It has two round liga-J- . ments which go from the fides of it to the groins 12, through the oblique and tranfverfe mufcles of the Abdomen, in the lame manner as to the feminal veiTelsin men. This way the gut pafies in a Hernia Intellinalis in women, (Vid. Muf- culi Abdominis.) Some authors mention Li- gamenta Lata, which are nothing but a part of the Peritoneum. Near the fides of the U- terus lie two bodies called Ovaria, they are Tab.xxix. of a depreffed oval figure about half the fize '^* of men's tefticles, and have fpermatic veflels; they contain fmall pellucid eggs, from which they have their name. There are two arteries and two veins, which pafs to and from the ova- ries or teftes, in the fame manner that they do in men •, but make more v/indings, and the ar- teries dilate more fuddenly, in proportion as as they are fhorter. Thefe arteries and veins detach branches into the Uretus and Fallopian tubes, and not only make communication be- twixt the artery and vein on one fide and thofe « of the other, but alfo with the proper vefTels of the Uterus detached from the internal iliac arteries 3 o 2 Of the genital parts of women. arteries and veins. From thefe vefTels both ar- teries and veins in the infide of the Uterus, the menftrual purgations are made in women, and fomething of the fame kind in brutes, as often as they defire coition. One ufe of thefe purgations is, to open the vefTels of the Ute- rus, for the velTels of the Placenta to join to them. Many authors have imagined that there mufl be fome evacuations analagous to this, in men, which I cannot fee the necefiity of; but on the contrary, I believe that men's not hav- ing fuch evacuations, is the true reafon why their bodies grow larger and flronger than womens; and their continuing to grow long- er before they are fit for marriage, I alfo take to be the true reafon why there are more males' born than females, in about the proportion of thirteen to twelve ; for women being fooner fit for marriage than men, fewer will die be- fore that time, than of men. Tab.xsix. N E A R the fides of the Ovaria, are feated 9- the Tubas Fallopianse, one end of which is conneded to the Uterus, and the fide to the Ovarium by a membrane, the other end being Tab.xxixJ^gg^^5 is called MorfusDiaboli. Among thefe lo. jaggs is a fm.all orifice which leads into the tube, which near this end is about a quarter of an inch diameter, and thence growing gradually fmaller pafTes to the Uterus, and enters there with an orifice about the fize of a hog's briflle. The Of the genital parts of women. 303 The ufe of thefe tubes is to convey the male feed from the Uterus to the Ovaria, to impreg^ nate the eggs for conceptions ; yet they are feemingly fo ill adapted to this end, that ma- ny writers have fuppofed there muil: be fome other paffage from the Uterus to the Ovaria ; but if we confider the cafe of conceptions found in thefe tubes , and the exad analogy between thefe and the tube of a hen, where we have the moil undeniable proofs of the feed going through the tube, and of the eggs being impregnated that way, and of the eggs coming from the Ovarium through .the tube, and feemingly with much greater difficulty than in women j and befides how frequently a mat- ter like the male feed, (which Ifuppofe is feed,) is found in the fallopian tubes ofwom.en, as I have found in executed bodies, and in acom^ mon whore that died fuddenly, it appears al- mofb certain, that the feed goes through the Fallopian tubes to the Ovaria to impregnate eggs, which come back through the fame tubes ■ to the Uterus. I have feen in a woman both the Fallopian tubes unperforated, which upon the foregoing hypothefis, muft have caufed bar- rennefs, and feed lodged in thefe tubes may have the fame efFe6t •, which I take to be often the cafe of common whores, and women that ufe coition too frequently ; and perhaps the fat in the membrane that connc6ls the Ovaria to, 304 Oj the gemtal parts of women. to the tubes, may in very fat womenj fo keep thefe tubes from the Ovaria as to interrupt im- pregnations •, and befides thefe cafes, too much or too little df the Menfes, may deflroy-or in- terrupt conceptions ; but the latter cafe, efpeci- ally in young women is very rare. From fuch caufes as thefe, and not from imbeeillity, I im- magine it is that barrennefs oftener proceeds from women than men; and though women do not propagate to fo great an age as men, it is not, I believe, for want of being impreg- nated, but from their Menfes ceafmg, and thofe veffels being clofed which fhould nourifh the Foetus after the inipregnation, as if on purpofe to prevent the propagation of a feeble and in- firm fpecies. And from this confideration one cannot but think that the perfedtion of theFoe-^ tus, notwithftanding it is firfl formed in the male feed, depends more upon the female than the male, or elfe that nature would, for the fake of the fpecies, have been careful to hinder men as well as women from propagating in a declining age CHAP. s 30s CHAP. III. Of the Foetus in Utero. THE Foetus in Uterd is involved in two coatSjViz. Chorion, which is external, and Amnion which immediately inclofes the Foe- tus. They contain a quantity of liquor, which is a proper medium for fo tender a being as the Foetus to reft in, and partly fecures it from ex- ternal injuries, as the aqueous humour does the cryftaline in the eye; and when the mem- branes burftat the time of production, this hu- mour lubricates the Vagina Uteri, to render the birth lefs diiBcult. And feeing the fto- mach of a Foetus in Utero is always full of a fluid like what is contained in the Amnion, and the guts always filled with excrements ; is it not reafonable to fuppofe that this fluid is frequently, during the time of geftation, fwallowed by the Foetus, if not for nourifh- ment, at leaft to keep thefe parts in ufe, and to flow through the ladteals (as a quantity of blood from the right ventricle of the heart, flows through the lungs before the birth) to keep open thofe paflages 'till the birth, there being after that time no other way of receiving nourifhment? And are not the Fseces found in the guts of a Fcetus chiefly thofe parts of this X fluid 3o6 Of the Foetus in Utero. fluid that were taken in at the mouth, and were too grofs to enter the ladeals ? Besides thefe coats, in a cow and many other animals, we find another membrane cal- led Allantoisj it is inclofed by the Chorion together with the Amnion, and contains a large quantity of water which it receives from the bladder of urine by the Urachus. Its ufe feems to be to contain the urine that it might not by the common palTage be emptied into the liquor of the Amnion, of which the Foetus, I am in- clined to think, is frequently drinking. Yet I own it takes off very much from the proba- bility of the opinion of the Foetus's imbibing this liquor, that, if I am rightly informed, fomc who have been born with mouths and noilrils. unperforate, have had fuch fluids and excre-. ments in the intefliines that other Fcetus's have, which may indeed be derived from the falivary glands and from the liver, &c. The following curious paflTage was fent me by Mr. Monro. *' This liquor contributes nothing to the nou- " rifhment of the Foetus for thefe reafonsj *' firfl:, becaufe, as you have well obferved, *' vafl: numbers of infliances might be produ- *' ced, where no paffage was to be found for *Mt: I fhall give you one I faw my felf in the *' Hotel de Dieu at Paris in 171 8. *' Mary Guerlin brought forth two children, *^ one a compleat girl^ the other had neither " head. Of the Foetus m Utero. 307 '' head, neck, arms, heart, lungs, ftomach, '' fmall guts, Hver, fpleen, nor Pancreas, yet ^' the great guts, the organs of urine and ge- '^ neration of a female, and lower extremities *' were perfe6t, and of a natural growth *, the " umbilical vein, after entering the Abdomen '' fplit into a great many branches, which were " diilributed to the fevera] parts in its Abdo- " men. Though it is true that foon after " conception, the liquor in the Amnion, and '^ that in the ftomach of the Foetus refemble '' one another pretty near, yet afterward they *' differ exceedingly, for the liquor in the ilo- " mach is ftill gelatinous, thick, knd without ^' acrimony, while the other becomes thinner *' and more acrid; whereas, had the Foetus *' conftantly fwallowed this liquor, the cafe " would have been quite oppoiite -, na}^, often " it has happened that theie waters (as they '^ are commonly called) have been found quite *' corrupted, flirongly fetid, and extreamly '' iharp, while the Foetus, except the injuries '* which the external parts received, was well *' and found; witnefs the example mentioned *' by Bellinger, of a w^oman who was cured of "a virulent Gonorrhea during her going with *' child. And farther by Malpighius's deli- *' neations of the Pullus in Ovo , it appears " to me evident that the Afitellus ferves the ^ fame purpofe as the Placenta does in vivi- X 2 *' parous o8 Of the Foetus in Utero. ^^ parous animals, to convey the Albumen " attenuated by incubation into the blood- " veflfels of the chick, and that none of the Al- " bumen does pafs through the Saccus Colli- *' quamenti. " Whether an Alantois is to be found with a human Foetus or no, anatomifts are not all agreed, and I cannot give my opini- on having never had a fufficient opportunity to enquire. But children having an Urachus one cannot well doubt of the Alantois. I have been informed by a gentleman, whofe probity I can fufEciently rely on, that he had feen a child that had no external genital parts, and made water through the navel. At Henly upon Thames, there is now living a barge- man's child about ten years old, of which child I had the like account; but upon exami- nation I found an unperforated Glans with its Froenum immediately below the place of the navel, and the urine ilTued out by drops between this and the belly, in the place which I fuppofe was the navel, but it was fo much excoriated, that I could make no certain judg- ment about it» In the Uterus of a cow with two calves, I found they had but one Chorion, but each an Amnion, and Allantois diftind:, but the cotyledons which are analogous to the. Placenta of the humane Foetus, were pret- ty Of the Foetus in Utero, 309 ty much in common to the umbilical blood veflels of both. The Placenta, or womb-liver, is a mafs of blood veflels feated on the outfide of the Chorion, being compofed of the extream bran- ches of the umbilical-vein and arteries, which are for the compolition of this part divided in- to exceeding fmall branches to join a like num- ber of the menftrual veffels of the Uterus, which velTels of the Uterus are made nume- rous rather than large, that the feparation of the Placenta from them may not be attended with a flux of blood fatal to the mother ; for the fides of little veiTels foon coUapfe and clofe, and they are more eafily flopped, being com- prefTed by the Uterus it felf as it fhrinks, which it begins to do from the time of the birth, but when the Placenta is feparated before the de^ livery, whether untimely or not, thefe veflels bleed until the Uterus is difcharged of the Foe- tus. The figure of the Placenta is circular, and at its greateft growth about two inches thick, and fix or feven diameter. The arteries and veins of the Uterus of the mother, by which the menftrual purgations are made, are joined to the umbilical arteries and veins in the Placenta of the Foetus, the arteries of the Uterus to the veins in the Placenta, and the veins in the Uterus to the arteries of the Placenta: By thefe velTels a large . quantity of X 3 blood II ii^Ml^ae L ■ ■ — ' 310 Of the Foetus m liter 0. blood is continually flowing from the mother to the Foetus and back again -, but for what end fuch a quantity flows continually and back again, I cannot conceive, unlefs it is that the Foetus not breathing for it felf, it is neceflary that as much blood of the mother fhould flow continually to the Foetus, as can leave enough air, or whatever our blood receives in the lungs for the Foetus ; and perhaps what nutritious juices the Foetus receives, require a great deal of blood to convey them, they being but a fmall part of the blood. The navel fl:ring or umbilical blood-vefiels, between the Placenta and the navel, are about two foot long, that the Foetus may have room to move without tearing the Placenta from the Uterus, which being done too foon, from whatever caufe, oc- cafions a mifcarriage. Thefe veflfels, viz. two arteries and one vein twifl: about each other, particularly the arteries about the vein, and are contained in one common coat together with a vefTel called Urachus, which arifes from the top of the bladder of urine, and ends in the Tab.xxxi. "^^nibrane Allantoisj the umbilical vein goes i» from the navel diredly into the liver, and there, enters the great trunk of the Vena PortJ^. Tab.xxxi. Near which entrance, there goes out the Dudus ^' . Venofus to the great trunk of the Cava, which 4.' * carries part of the blood that is brought; by the umbilical vein, that way into the Cava, while the > " Of the Foetus m Utero, 311 the reft circulates with the blood in the Porta, the whole of it not paffing through the Dudus Venofus as is generally believed, but a great part of it into branches of the Porta, in the Tabxxxi, liver, otherwife there need be no communica- 2* tion between the umbilical vein and the Porta^ and when the umbilical vein is ftopped, it be- comes a ligament, and the Du(5lus Venofus foon ihrinksand almoft difappears, having no longer any blood flowing through it ; and even the Porta it felf within the liver (from whence only blood could pafs after the birth into the Dudus Venofus) has lefs blood flowing through it for fome time than it had before the birth, it re- ceiving much blood before the birth from the umbilical vein. The blood which flows from the mother to the Foetus by the umbilical vein, is returned (all but a fmall quantity, which is referved for nutrition) by the two umbilical ar- teries, which arife from the internal iliac arte- ries, and pafling by the outfides of the blad- der go diredly to the navel and Placentas thefe with the Urachus being fhrunk up after the birth, lofe much of their appearance, efpe- cially near the navel, where they are fometimes not be diftinguiihed. Part of the blood before the birth and not the whole quantity as is generally thought, which is brought by the afcending Cava to the right auricle, pafles at once through the Fora- X 4 men 312 Of the Foetus in Utero. men Ovale into the left auricle, and the reft flows into the right ventricle with the blood of the defc ending Cava, and thence into the pulmonary artery, where about one half flows into the lungs, and the other half dire6tly in- to the Aorta by the Du6bus Arteriofus, which lies between the pulmonary artery, and the A- orta, which after the birth is called Du6tus Ar- teriofus in Ligamentum Verfus. The better to explain this contrivance, I will call the quan- tity of blood flowing through the afcending Cava in a given time four, and that which flows through the defcending Cava two: Then let two of the quantity in the afcending Cava flow into the right auricle, it will then with the two received from the defcending Cava have the quantity four ; which being thrown from the right ventricle into the pulmonary artery, the quantity two is thrown into the Aorta by the Du6lus Arteriofus, and the fame quantity into ,the lungs by the pulmonary branches, then the quantity returning from the lungs to the left auricle, will be two in the fame given time, which being added to the two which flowed through the Foramen Ovale, in the fame time there will be conftantly the fame proportions received into each ventricle at every Diafl:ole of the ventricles as after the birth. Now if the blood flowing through the afcending Cava join- ed by that from the umbilical vein, was but ^ equal Of the Foetus in Utero. 313 equal to that flowing through the defcending, let each of them be called two, and let all the blood of the afcending Cava go through the Foramen Ovale; then the blood which the left ventricle would receive, would exceed that which flows into the right, by the whole quan- tity which flows from the lungs in the fame time; but the afcending Cava conveying more blood than the defcending Cava, the excefs in the left ventricle would be yet greater. If the proportions which I have taken for the eafier computing were perfe6lly right, as I am fure they are nearly, then the quantity flowing into the left ventricle, would be to that flowing in- to the right at the fame time as five to two, if all the afcending blood went through the Foramen Ovale. And though after the birth the left ventri- cle of the heart is only employed in throwing blood into the Aorta, and the right wholly employed in circulating the blood through the iungs; yet before the birth all the blood thrown out by the left ventricle, and about half the blood thrown out of the right ventricle, being thrown into the Aorta, and the other part on- ly through the lungs, it follows that the whole force exerted by the left ventricle, with about half that of the right, is employed in throw- ing blood into the Aorta, while that diilributes blood through the whole Foetus and to the mo- ther 314 Of the Fwtus in Utero. ther: But after the birthwhen the blood is to be no longer carried from the Foetus to the mother, the left ventricle becomes fufficient for the cir- culation through the Foetus, and a new occa- fion immediately arifes for that additional pow- er, which before was neceffarily employed in throwing blood into the Aorta -, for the whole mafs of blood now being to be circulated through the lungs, the Du6tus Arteriofus clofes, and the right ventricle mull throw all the blood it receives into the lungs, there be- ing no longer any paffage into the Aorta. It is fuppofed that the inflation of the lungs at the birth, prefently alters the pofition of the Duc- tus Arteriofus, fo as to obftrudl it; which ac- count is indeed mechanical, but I think not true, becaufe I can neither difcern that the po- fition of this vefTel is altered, nor its furface comprefTed : But I rather think that immedi- ately upon the birth, there being no blood carried off from the Foetus to the mother, and the left ventricle being fufHcient to fill the Aorta and its branches with blood, as I have fhewn before, there is no longer room for any blood from the right ventricle ; wherefore the blood from the right ventricle will be forced into the lungs, where the paffage is now made eafy,as I imagine, by their being inflated ; and the Dudtus Arteriofus, having the blood no longer forced into it, fhrinks, and in time al- mofb Of the Foetus m Utero. 3 1 y mofl difappears. This du6t being flopped, the valve of the Foramen Ovale immediately flops that pafTage, it being on the fide of the left auri- cle (or that miifcular bag, which is the largefl part of that auricle) which is much the flrong- efl, mufl at all times be prefTed more on that fide than the other by the blood in the time of the Syflole of the auricle; and it is as evident that in the Diaflole of the auricle, there mufl be more prefTure to open that than the rights it being a ftronger mufcle, or elfe there could have been no reafon for having the left auricle ftronger than the right in proportion to their ventricles. Sometimes this valve does not quite cover the Foramen, in which cafe a fmail quantity of blood may polTibly f^ow from the left auricle to the right, and fo circulate twice through the lungs to once through the body, but none could flow from the right to the left and efcape the lungs, which might be of bad confequence. Some have imagined, that men who have this pafTage open, cannot be drown- ed: But though this pafTage is fometimes found open, no Man has been yet ^^Qn^ that we have ever heard of, that could not be drowned. I have ittn the Foramen open in a man that was hanged , to whom one might juflly exped it fliould have been as ufeful as m the cafe of fabmerfion in water. Many v/riters have fuppofed that this Foramen is open in am- phibious 3 1(5 Of the Foetus m Utero. phibious animals, and in fuch fifhes as have two auricles, two ventricles, and lungs like land animals, without gills (which in other fifh are analogous to lungs.) I have difleded a porpus which is of this kind, and found this Foramen clofed •, but the great veins were vall- iy large in proportion to the bulk of the animal i whence I conjedlured their blood was accumu- lated in their veins, while they kept under wa- ter, and by that means the lungs efcaped be- ing opprefled with blood; which conjedlure feemed to me the more probable, fince all ani- mals of this kind are able to abide theleaft time under water, when their blood is moft expand- ed with heat. But upon the difledion of an otter, whofe Foramen Ovale was alfo clofed, I found the veins nothing differing from thofe of other animals. In a water tortoife which T had an opportunity of examining , with that mofl dextrous and indefatigable anatomifl Dr. Dou- glafs, I found the two ventricles of the heart but half divided by a Septum, and in the be- ginning of the pulmonary artery feveral ftrong mufcular rings, a little diftance from each other, each of which by contrading, would be capable of refifting a part of that blood, which other- wife would have been thrown into the lungs, when they were under water ; and this blood fo obftru6led mull neceffarily be thrown into the Aorta, the two ventricles being in a manner one Of the Foetus m Uterm. 317 one common cavity ; and when they are out of the water, this communication of ventricles, will fuffer but little confufion of the blood which flows into the ventricles, becaufe each ventricle receiving and difcharging the fame quantity of blood, at the fame time, they will balance each other, and thereby fuch a mixture will be very much prevented. Mr. Monro obferves that the water tortoife has very large lungs, confifting of larger veficles than land animals, and that they receive a greater quantity of air to furnifli that Je ne fgai quoi fo necelTary for the life of animals : The fame thing I remember to have obferved in frogs. As to the reafon of womens bringing forth at the ufual time •, it has been faid, that at that time, the head of the child begins to be fpeci- fically heavier than the reft of the body, and therefore muft fall loweft in the fluid it lies in ; which being an uneafy pofture, makes the child ftruggle, and bring on the labour. But it is not true, that the head then alters its fpecific gravity; or if it did, there is feldom fluid e- nough in the Amnion for this purpofe , and be- fides, this could only happen right in one po- fl:ure, and would always happen wrong in brutes. CHAP. 3i8 C H A P. IV. Of the eye, THE figure, fituation, and ufe of the eyes, together with the eye-brows, eye-laihes, and eye-lids, being well known, I think, I need only defcribe what is ufually ihewn by dilTed:- ing. The orbit of the eye, or cavity in which it is contained, is in all the vacant places filled with a loofe fat, which is a proper medium for the eye to reft in, and ferves as a focket for it to be moved in. In the upper and outer part of the orbit, is feated the lacrymal gland. Its ufe is to furnifh at all times water enough to wafh off duft and to keep the quter furface of the eye moift, vv^ithout which the Tunica Cornea would be lefs pellucid, and the rays of light would be difturbed in their paflage ; and that this liquor may be rightly difpofed of, we frequently clofe the eye-lids to fpread it equally, even when we are not confcious of doing it. At the inner corner of the eye, be- tween the eyejids, ftands a caruncle, which feems to be placed to keep that corner of the eye-lids from being totally clofed, that a- ny tears or gummy matter may flow from under the eye-lids, when we fleep, or into the Punda Lacrymafia, which are little holes, one in each eye-lid. Of the Foetus tn Utero. 3 1 c> eyelid, near this corner, to carry off into the Du6lus ad Nafum, any fuperfluous tears. The firft membrane of the eye is called Conjunctiva, it covers fo much of the eye as is called the v/hite, and being reflefted all round it lines the two eye-lids ; it being thus returned from the eye to the infide of the eye-lids j it effedluaily hinders any extraneous bodies, from getting behind the eye, into the orbit, and fmooths the parts it covers, which makes the friction lefs between the eye and the eye-lids. This coat is very full of blood veiTels, as ap= pears upon any inflammation. Tunica Sclerotis, and Cornea, make together one firm cafe of a proper form , for the ufe of the other coats and humours. The fore part of this ilrong coat being tranfparent, and like horn, is called Cornea, and the reil Sclerotis. Under the Cornea lies the Iris which is an opake membrane, like the Tunica Cho- roides, but of different colours in different eyes, fuch as the eye appears, as grey, black, or hazel, for it being feated under the Tunica Cornea, it gives fuch an appearance to that as it has its felf. The middle of it is perforated for the admilTion of the rays of light, and is called the pupil. Immediately under the Iris Ue the, ProcelTus Ciliares, like radial lines from a lefTer circle to a greater. When thefe procef- fes contrad they dilate the pupil to fuffer more ^ rays 3 2 o Of the eye. rays of light to enter into the eye ^ and the contrary is done by the circular fibres of the Iris, which adl as a fphindter mufcle : But thefe changes are not made with great quicknefs, as appears from the eyes being opprefTed with a ftrong light, for fome time after we come out of a dark place, and from the contrary effedt in going fuddenly from a light place to a dark one. And as the pupil always dilates in darker places, to receive more rays of light, fo when any difeafe makes fome of thofe rays inefFedual, which pafs through the pupil, it dilates as in dark places to admit more light ; therefore a dilated pupil is a certain fign of a bad eye , and this may be difcerned ufually fooner than the patient difcerns any defed in vifion. In men the pupil is round, which fits them to fee every way alike; it is alfo round in animals that are the prey both of birds and beafts. But graminivorous brutes that are too large to be the prey of birds, have it oblong horizon- tally, which fits them to view a large fpace up- on the earth; while animals of the cat-kind who climb trees, and prey indifferently on birds or animals that hide in the earth, have their pu- pils oblong the contrary way, which fits them beft to look upward and downward at once. Befides thefe there are other animals whofe pupils are in thefe forms, but in lefs propor- tions, fo as beft to fit their ways of life. Imme- diately Of the eye, 321 diately under the Sclerotis, is a membrane of little firmnefs called Choroides; in men it is of a rufly dark colour^ fuch as will bury almoil ail the rays of light, that pafs through the Tuni- ca Retina, which if it were of a brighter colour, would refled: fnany of the rays upon the Retina, and make a fecond image upon the firfl fome- what lefs, and lefs diflind, but both together ftronger 5 which is the cafe of brutes of prey, where a great part of this coat is p erf edlly white, which makes them fee bodies of all colpurs in the night better than men, for white refleds all colours : But brutes that feed only on grafs, have the fame parts of this membrane of a bright green, which enables them alfo to fee with lefs light, and makes grafs an dbjedt that they cart difcern with great eft ftrength: But thefe advan- tages in brutes, rieceffarily deftroy great accu- racy in vilion , which is of little or no ufe to them, but to men of great confequence. This green part of the Tunica Choroides, iii animals that graze, may properly be called Membrana Uvea^ from its refemblance in colour, to ail unripe grape. But in men's eyes, only a white circle round the back fide of the Choroides near the Cornea, is called Uvea. Immediately under the Tunica Cho- roides, lies the Tunica Retina, which is the, optic nerve expanded and co-extended with the Choroides, Rays of light ftriking upon Y this ■<^r XXXll. 3?,x Of the eye. this membrane, the fenfation is conveyed by the optic nerves, to the common Senforium the brain ; thefe nerves do not enter at the mid- dle of the bottom of the eyes, but nearer the nofe-, for thofe rays of light being inefFe6lual for vifion that fall upon the entrance of the op- tic nerves, it is fit they fhould fo enter, as that the fame objed, or part of ariy objed, fhould not be unperceived in both eyes, as would have been the cafe, had they been otherwife inferred ; which appears from a common ex- Tab, periment of part of an obje6t being lofl to one eye, when we are looking towards it with the other (hut. I know a gentleman who having lofl one eye by the fmall-pox, and going through a hedge a thorn unfeen (probably from this caufe) flruck the other and put it out. The two optick nerves foon after they arife out of the brain join and feem perfe6tly united, yet from the following cafe, I am not without fuf- picion of their fibres being preferved diflind, and that the nerve of each eye, arifes wholly from the oppofite fide of the brain, or elfe that the other nerves throughout the body arife from the brain, and Medulla Oblongata on the fides oppofite to thofe they come out of A fol- dier who was my patient in the hofpital about five years fince , had , by a pufh with a broa4 fword, his left eye raifed out of the orbit, which I replaced with my fingers j it was pre- fently Of the eye. 323 itntly followed with excefTive pain in the right lide of the head only, and a lofs 6f the fenfe of feeling and motion in both the right limbs; the fenfe cif feeling he recovered by degrees in a- bout a rhonth, and foon after began to recover their motion, but was about tv/elve months before he could walk, and lift up his hand to his head; and in about two years recovered, all but the fight of the wounded eye, which in- deed did not appear perfed. In fifh thefe nerves arife diftind from the oppolite fides oi the brain , and crofs without uniting •, but' as thefe animals have their eyes fo placed, as not to fee the fame objedt with both eyes at once, whereas animals whofe optic nerves feem to u- nite, do fee the fame obje6t with both eyes at once, one would fufpedl that in one they were joined to make the objedl not appear double,' and in the other diflincl , to make their two eyes (as they are to view different objects at the fame time) independent on each other; and yet from the following cafes, the feeing ob- jefts fingle feems hot to depend upon any fuch union, nor from the light flriking upon corre- fponding fibres of the nerves, as others have believed, but upon a judgment from experi- ence, all objedls appearing fingle to both eyes in the manner we are moft ufed to obferve them, but in other cafes double ; for though we have a diftind image from each eye fent to y 2 the 3 14 Of the e^e. ^ the brain^ yet while both thefe images are of an objedt i^txi in one and the fame place, we con- ceive of them as one, fo when one image ap- pears to the (eyes when they are diftorted or wrong dire6led) in two different places, it gives the idea of two 5 and when two bodies are feen in one place, as two candles rightly placed, through one hole in a board, they appear one. But cafes of this kind being too numerous, I will conclude with one very remarkable, and I think much in favour of this opinion. A gentleman who, from a blow on the head, had one eye diftorted, found every objed appear double, but by degrees the moft familiar ones became fmgle, and in time all objedls became fo, without any amendment of the dillortion. The infide of the eye is filled with three humours, called aqueous, cryflalline and vi- treous. The aqueous lies foremoft, and feems chiefly of ufe to prevent the cryftalline from being eafily bruifed by rubbing or a blow, and perhaps it ferves for the cryftalline hum.our to move forward in while we view near objeds, and backward for remoter objefts -, without which mechanifm, or in the place of it a great- er convexity in the cryftalline humour in the former cafe, and a lefs convexity in the latter, I do not imagine, according to the laws of op- tics, how we could fo diftindly fee objeds at different diftances. However it is in land ani- mals. Of the eye. 325 mals, I think we may plainly fee, that fifh move their cryftalline humour, nearer the bottom of the eye when they are out of water, and the contrary way in water; becaufe light is lefs re- fracted from water through the cryilalline hu- mour than from air. Some have faid, that am- phibious animals have a membrane like the Membrana Niditans of birds, which ferves them as a Lens in the water. I have examined the eye of a crocodile, which Sir Hans Sloan keeps in fpirits, and I found this membrane equally thick and denfe, and confequently unfit for this purpofe, or I believe any other except that ob- vious one, of defending the eye from the water. Next behind the aqueous humour lies the cry- ftalline ; its fhape is a depreffed fpheroid , it is diftindly contained in a very fine mem- brane called Aranea. The ufe of this humour is to refradt the rays of light which pafs through it, fo that each pencil of rays from the fame point of any objed, may be united upon the Retina (as in a Camera Obfcura) to make the ftronger impreflion -, and though by this union of the rays a piClure inverted is made upon the Retina, yet furely it is the impulfe only of the rays upon the Retina, that is the caufe pf vifi- on •, for had the colour of the Retina been black, and confequently unfit to receive fuch a pidture, would not the impulfe of light upon it have been fufHcient for vifion? Or would fuch a pic- Y 1 ture. Of the eye. ture, if it could have been made without any im- pulfe, have ever conveyed any fenfation to the brain P Then if the impulfe of light upon the Retina, and not the image upon the Retina, is the caufe ofvifion; when we enquire why an image inverted in the eye appears otherwife to the mind, might we not expe6l to find the tru^ caufe from confidering the direftions in which the rays ilrike the Retina^ as we judge of above and below from a like experience, when any thing ilrikes upon any part of our bodies ; ne- verthelefs in viewing an objedl through aLeps, we conceive of it as inverted , whenas in re- ceiving the impulfes of light in the fame man- ner, and having the pi6lure on the Retina in the fame attitude, when v/e fiand on our heads without the lens, we have not the fame, but the contrary idea of the pofition of the obje(5l. Though 1 have confidered this humour only as a retradpr of light, yet the firll and greateft refradion is undoubtedly made in the Cornea; but it being Concavo-convex, like glafTes of that kind, v/hile one fide makes the rays of light converge, the other diverges them again. The fame thing alfo may be obferved of the a* queous humour, v/hich is indeed more concave than convex^ but when the cryftalHne hu- mour is removed in the couching a catara6t the aqueous poffeffes its place and becomes a Lens 9 but that refrafting light lefs than the cryftalline. ll Of the eye. 327 cryflalline, wliofe place and fliape it partly takes, the patient needs a convex glafs to fee accurately. In fome eyes either this humour being too convex or too diftant from the Re» tina, the rays unite too Toon unlefs the obje6t is held very near to the eye, >yhich fault is re- mediable by a concave glafsj as the contrary ftult (common to old perfons) is by a convex glafs. Here it may not be improper to ob- ferve, how wifely providence has fixed the di- fiance, at which we ordinarily fee objects beft, for if the eye had been formed for a nearer view, the objedl would often obflrudl the light ; if ir had been much farther, light enough would not commonly have been produced from the objed to the eye. In fiih the cryflalline hu- mour feems a perfe6t fphere, which is necelTa- ry for them, becaufe light being lefs refraded from water through the cryflalline humour than from air, that defeat is compenfated by a more convex Lens. The vitreous humour , lies behind the cryflalline, and fills up the greatefl part of the eye: Its forefide is concave for the cryflalline humour to lodge in, and its backfid© being convex the Tunica Retina is fpread over it -, it ferves as a medium to keep the cryflalline humour and the Retina at a due diflance. The larger animals having larger eyes, their organs of vifion (like a microfcope with a large . y 4 Lem) ■ ' "■■ ■ --J. ' ' ' SJ 328 Of the ear. Lens) are fit to take in a greater view, but in that view things are not fo much magnified ; fo in the lelTer animals a fmall fpace is dif- cerned, fuch as is their fphere of a6lion, but that greatly magnified, not really fo iij either cafe, but comparatively \ for yifion Ihews not the real magnitude of obje6ts , but their pro- portions one to another. Fifh have their eyes, and particularly their pupils, larger than land animals, becaufe there is lefs light, and that not fo far diftributed in v/ater as in the air. C H A P. V. Of the ear. THE figure and fituation of the outer ear^ needs no defcription. Its inner fubilance is cartilage, which preferves its form without being liable to break: Its ufe is to cqlledt founds, and dlred: them into the Meatus Auditorius, which is the pafiage that leads to the drum \ this paffage is lined with a glandular membrane, in which alio is fome hair ; the Cerumen which is feparated by thefe glands, being fpread all over this membrane^ and its hairs, ferve to defend the membrane from the outer air^ and to entangle any infedl: that might other- ► wife get in^ro the ear. Sometimes this wax be- ing Of the ear. 329 ing feparated in too great quantity, it fills up the paflage and caufes deafnels -, and thofe great difcharges of matter from the Meatus Audito- rius, which are commonly called impoilumes in the ear, I think can be nothing elfe than ul- cerations, or great fecretions from thefe glands. At the farther end of the Meatus Auditorius lies the drum, which is extended upon a bony ridge almoft circular : Its fituation in men and brutes is nearly horizontal, inclined towards the Meatus Auditorius, which is the beil po- rtion to receive founds ; the greateil part of which being ordinarily reverberated from the earth. In its common lituation in men and brutes, it is concave outward, but in birds it is convex outward , fo as to make tKe upper fide of it nearly perpendicular to the horizon, which ferves them better to hear each others founds when they are high in the air, where they can receive but little reverberated found. This membrane does not entirely clofe the paiTage^ but has on one fide a fmafi aperture covered with a valve. I found it pnce half open in a man that I difTedted, who had not been deaf, and I have feen a man fmoak a whole pipe of t9bacco out through his ears, which muft go from the mouth, through the Eullachian tube, and through the Tympanum, yet this man heard perfectly well. Thefe cafes occafioned mc to break the Tympanum in both ears of a doe. 330 Of the ear. dog, and it did not deflroy his hearing, but for fome time he received ftrong founds with great horror. And that moil' excellent anato- mid Mr. St. Andre, to whom I am greatly ob- liged in this chapter , has allured me, that a patient of his had the Tympanum deftroyed by an ulcer, and the auditory bones caft out, with- out deftroying his hearing. In very young children I have always found this membrane covered with Mucus, which feems neceflary to prevent founds from affedling them too much, there being no provision to Ihut the ears, as there is for the eyes. A gentleman well known in this city , having had four children born deaf, was advifed to lay blillers upon the heads of the next children he might have, which he did to three which were born after- ward, and every one of them heard well. It ieems not unreafonable to fuppofe that to0 great a quantity of this Mucus upon the drum, might be the caufe of deafnefs in the four chil- dren, and that the difcharge made by the blifters in the latter cafes, was the caufe of their efcaping the fame misfortune. Into the middle of the Tympanum is ex- tended a fmall bone called Malleus, whofe o- ther end is articulated to a bone called Incus, which is alfo articulated by the intervention of an exceeding fmall one called Orbiculare, to a fourth bone called Stapes. Thefe bones 3 are Of the ear. are contained in that cavity behind the Tym- panum, which is called the barrel of the ear; but fome anatomifts call the barrel only Tym- * panum^ and the membrane Membrana Tym- pani. The Malleus being moved inward by the Mufculus Obliquus Internus, or Troch- iearisj it extends the Tympanum that it may be the more affe6ted by the impulfe of founds when they are too weak. This mufcle arifes from the cartilaginous part of the Euftachian tube, and pafling from thence in a proper groove, it is reflected under a fmall procefs, and thence pafles on perpendicular to the Tympanum, to be inferted into the handle of the Malleus, fometimes with a double tendon. Parallel to this mufcle lies another Extenfor of phe Tympanum, called Obliquus Externus; it arifes from the outer and upper part of the Eu- ftachian tube, and pafling through the fame hole with th^ Corda Tympani, which is a branch of the fifth pair of nerves, it is inferted into a long procefs of the Malleus : This is not fo obvious an Extenfor as to be known to be fo, without an experiment. The mufcle which re- laxes this membrane is called Externus Tympa- 111 ; it arifes from the upper part of the audito- ry paffage under the membrane which lines that pafiage, and is inferted into the upper procefs of the Malleus. The relaxation of the Tympa> num is made by this mufcle, without our know- ledge. 33 2 Of the ear. ledge, when founds are too ftrong ; and as the pupil of the eye is contra6ted, when we have too much light, and dilated where there is too little, from what caufe foever, fo when founds are too low, or the fenfe of hearing imperfe6l, from v/hatever caufe, the extenfors of the Tym- panum ftretch it, to make the impulfe of founds more efFe(5lual upon ir, juft as in the cafe of the common drum, and the cords of any muiical inftrument. From the cavity behind the Tym- panum., which is called the barrel of the ear, goes the puflachian tube, or Iter ad Palatum ; it ends cartilaginous behind the palate. This paiTage feems to be exaftly of the fame ufe with the hole in the fide of the common drum, that is to let the air pafs in and out from the bar- rel of the ear, %q riiake the membrane vibrate the better, and perhaps in the ear (which is clofer than a common drum) to let air in or out as it alters in denfity, and if any fluid ihould be feparated in the barrel of the ear to give it a paiTage out. This paiTage being obilrudled, as it is fometlmes, by a large Polypus behind t\\t Uvula, it caufes great difficulty of hearing, and fometimes, when the Meatus Auditorius is obftruded, a man opening his mouth wide, will hear pretty well through this pailage, which is often fo open as that fyringing water through the nofe, it fliall pafs through into the barrel of the ear and caufe deafnefs for fome time. If Of the ear. 333 If any one would try how he can hear this way, let him flop hisears, and take between his teeth the end of a wire, or cord that will vibrate well, and holding the other end, ftrike it, and the found that he hears will be through this pafTage. To the Scapes there is one mufcle called Mufculus Stapedis-, it lies in a long chan- nel, and ending in the Stapes, it ferves to pull the Stapes off of the Feneflra Ovalis, which o- therwife it covers. Beiides the Feneflra Ova- lis, there is another near it fomewhat lefs, called Rotunda; thefe two holes lead to a cavity called Veflibulum, which leads into other cavities aptly called Cochlea, and three femicircular canals or altogether the labyrinth, in which are fpread the auditory nerves to receive and con- vey the impulfe of founds, to the common Sen= forium the brain ; and furely the Chorda Tym- pani, which is a branch of the fith pair of nerves may alfo convey thefe fenfations to the brain. The two holes called Feneflra Ovalis & Rotun- da, are clofed with a fine membrane like the membrane called the drum, and the larger be- ing occafionally covered and uncovered by the Stapes, founds are thereby made to influence more or lefs, as befl ferves for hearing, and this advantage, being added to that of a lax or tenfe Tympanum, the etFecl of founds may be greatly encreafed or lefiened upon the auditory nerves, expanded in the labyrinth. In the 3 ftrongeft 334 Of the fenfes of fmellmg^ ftrongeft founds, the Tympanum may be lax, and the Feneflra Ovalis covered, and for the loweft the Tympanum tenfe and the Feneflra tincovered. If founds propagated in the air were heard lefs, we nnight often be in danger . before we were apprized of it, and if the organs of liearing were much more perfed, unlefs our underftandings Were fo too, wefhould cornmon- ly hear more things at once than we could at- tend to. CHAP. VI. Of the fenfes offmellmgy tajling and feeling. THE fenfe of fmelling is made by the Ef- fluvia, which are conveyed by the air to the nerves, ending in the membranes which line the nofe and its Lamellae. In men thefe Lamella are few, and the paflage through the nofe not difficult; hence fewer Effluvia will ilrike the nerves, than in animals of more exquifite fmell, whofe nofes being full of La- mellas, and the pafTage for the air narrow and erooked, few of the Effluvia efcape one place or another, befldes their olfadlory nerves may be more fenfible. Filh, though they have no nofes, yet in their mpuths they may tafte Ef- fluvia tajiing and feeling. ' 335 fiuvia in the water, as furely thofe fifh do, who feek their prey in the darkeft nights, and ingreat depths of water, there being more nerves dif- pofed in their mouths, than through their whole bodies befide, the optic excepted j and it looks as if it was done for this purpofe -, for the mere fenfe of tafling, is ordinarily lefs curious in them, than in land animals ; in baiting eel bafkets, if the bait has lain long in water, it is feldom taken, but upon fcarifying it afrefh, which will make it emit new effluvia, it ferves as a freih bait. The fenfe of tailing is made in the like man- ner upon the nerves, which line the mouth, and fo is that of feeling upon the nerves , di- ftributed throughout the body ; of which , I Ihould fpeak largely in this place, if I had not done it already in the chapter of the nerves. TABtE 33<^ Uiii^S TABLE XXVII. The urinary and genital parts of a man. .!» Arteria Aorta Defcendens^ 2, Vena Cava Afcendens. 3, 3. The emulgent veins. 4, 4. The emulgent arteries. 5. The left kidney. 6. The emulgent vein taken out of the right kidney. 7, 7. Glandulse Renales. 8, 8. The Ureters. 9. Part of the bladder of urine. 10. The Pelvis of the right Ureter taken 6ut of the kidney. 1 1 . The Tubuli Uririarii taken oHit of the right kidney. 12. The fpermatic arteries. 13. The fpermatic veins, the right entering the Cava, and the left the emulgent. 14^ 14. CoUateralbranchesdf the fpermatic vein, v/hich on this fide are not laid bare, and feparated from the artery which runs in the fame membrane with it. 15. The left tefticle included in the Prdceflus Vaginalis or Elythroides. 1 6, The right tefticle denuded. 17* The 337 17. The right Epididymis. 18. 18. The Vafa Deferentia. 19. 19. The Veficulae Seminales. 20, 20. The Proftatse. 21. The Roftrum Gallinaginis in the Ure- thra. 22. Two probes put into the ureters, to Ihew their oblique paflage into the bladder of urine. A, A, A tranfverfe fedlion of l;he Penis prepa- * red with Mercury. 23. The two arteries of the Penis. 24. The Vena Ipfius Penis. 25. The Urethra. 26, 26. The Corpora Cavernofa Penis. 27. The Corpora Cavernofa Urethra, TABLE 338 TABLE XXVIII. ' A, The teflicle of a fat. B, B, The Epididymis. Q The fame tefticle divefledof the Tunica Albuginea, aiid magnified to fhew the Convolutions of the ve'ffels. D, An inward portion of the fame teflicle more magnified. E, A Group of Animalculse, as they appear in the male feed in amicrofcope, and Byq other befides more magnified, but not reprefented enough like Tadpoles. TABLE <^^2j^.33/ (^^^.33^ ^.^m.:kxvc /. '^ i^ucAe- j\-til/j . 339 TABLE XXIX. -The parts 6f generation in women, the lower fide of the Vagina being laid upward, a$id<:iiit Qpen. 1,1. Th€ Labia, 2., 2. The Nymphas. 3. The Glans of the Qitom extreanily larg€, 4. The Prseputiunl of the Clitori. 5. The orifice of the Meatus Urinarius. -6i The infide of the Vagina where the Rugse are to be feen. 7. Os Tincse. 8. Uterus. 9,9. Tub« Fallopia-rise. io, 10. Fimbriae* II, II. Ovaria; ' 12^ 12. Ligamenta Rotunda. Z 2.- TABLE 34° TABLE XXX Represents the parts of an hermophra- dite, in which appeared as much of the mixture of the fexes as could be j (but Dr. Douglas, to whom I am obliged for this cut, and the refe- rences, efteems it a female.) I once examined another, in which I found a divided Scrotum juft like the Labia Pudendi, with tefticles in it, and a urinary pafTage between them, with a perfedt Clitoris as large as a Penis, with an ex- ceeding fmall Urethra, through which came a little urine. Fl G U R E I. I. The Clitoris covered with its Prseputium. 2, 2. The two Labia Pundendi. F I G U R E 2. 3. The Clitoris covered with its Prseputium. 4. The Glans of the Clitori. 5. 5. The Nymphs. 6. D. The Labia turned back, to Ihew the en- trance into the Vagina marked 7. 8. The Furca Virginalis, or the fkin that joins the two Labia at their lower part. TABLE "Pa^ .^f-^ .jk^j'^yx ^... iiiife; iy£ ^^.JT. c^t^Aii^^ O^tz^ . 3f*-^ 341 TABLE XXXI. The vejfels of the liver ^ &"€. of a Foe- tus y filled with wax-. 1,1. The umbilical vein. 2. Branches of the Vena Portse. 3,3, &:c. The exream branches in the liven 4, 4. The Du6lus Venofus. 5,5, Src. The extream branches of the Cava in the liver. 6, 6, 6. The afcending Vena Cava, 7. The Foramen Ovale. ■ 8. The mouth of the coronary veins. 9. Part of the right auricle of the heart. 10. Part of the defcending Cava. 11. Tuberculum Loweri. TABLE IT" - ■ ■ 34^ t ABLE XXXII Shews how all the rays that flow from any point of any object, through the pupils of the eyes, are refra6ted by the cryftalline humour, to meet in a Focus upon the Retina v the two dark tones fhew the fpaces where, any objeft being placed, it is not perceived in that eye in which the cone ends •, becaufe all the rays of light from an obje6t fo placed, fall upon the entrance of the optic nerve in that eye. ( Vid, page 245.) Thefe cones divaricating as they proceed fromthe eyes, they can never coincide, and confequently, though an objeft may be from this taufe un= dilcerned by one eye, there is no place from which it will be upon this account undifcerneci by the other eye. TABLE (^(Z^ . 3 ^2, (7'a^,^f^'2^ S^. XXXIII. 1 **^*^.=,^ 543 ■vmMM^^i T ABLE XXXIII. Fig. I She ws what will be the efFedi: of an opake- licfs, in the forepart of the eryflalline humour. FlQ. 2 Shkws what will be the efFed, when parts of the Retina are not fenfible of the light that falls upon them. F I G. 3 Shews what will be the effed of opakenefs in the vitreous humour. By confidering the efFedls of difeafes within the eyes in this manner, the fituation and extent of a difeafe in the eyes may, in moft cafes, he known to great exaftneft. Z4 TABLE 344 TABLE XXXIV. Fig. I. Shews how the light may be perceived only fide-ways, when as much of the Tunica Cornea is become opake as lies before the pu- pil. Fig. 2. Shews how it happens that in the cafe of acatarad:, which is a difeafe in the cryftalline hu- mour, light is perceived fide-ways after vifion is quite lofc forwards. TABLE TABXXXIV; (^a^.^^^- 5^. 341 SYLLABUS, S I V E I N D E X Humani Corporis partium prsecipuarum ANATOMICUS, In XXXV Praeleaiones diftinaus. ML b^^^^^.0^ ^^^^^ 9'iBM^^0t^ /'"^^mSMW /-i^^^^^^J'^i j^^^M^^^Mfli£^ff^ ^S^^^^mS^^ ^^^^m^^S^ <^y'~|f^^^^|{[' L^%,^^^^^^ ^J|P^ i^^^LM^-o^fe «C^^j§5®j^'^^^^^^^^^'^^ \ OSTEOLOGIA. Prceledio Prima. T)e Articulationibus ^ Stru£iura OJpum. T\larthroris JEnarthrofis. IJ (^Ginglimus, Synchondrofis. Sy„arthr<^:s, ^^IZ^^,,,, Pr^eleftio Secunda. 2)^ OJlmm texturaj Membrmifque^ &:a Fibras. InTexturafunt obfervanda rr iDras. ] Panes j™"^P^^f- Pericranium. Membrane jPeriofteum. ' iGlandulofse Celiulas inveilienteSc Medullaiia contifiqntes„ edulla 348 SYLLABUS. I^languinea. r Epiphyfibus, & Apophyfibus in genere. De < Introku & exitu Vaforum. cOlTium nutritione & incremento. Pr^Iedio Tertia. 2)^ Suturis ^ OJJibus Cranii. Coronalis. iSagittalis. Sutura\Lambdoidalis.— — OJfa Triquetra* (Squamofa. Tranfverfalis. CiBtercB ah OJfihus^ qu^Innominatus. iSalpingoides. ClinoideSc e 1. -t Sella Turcica. Sphenoides,^ rpHmum. jfecundum, vel lacerum. ForamenXtertium. quartum. quintum. Sinus Sphenoidalis. TemporiSj S T L LA B U S. 349 -p . CProcelTus Mammillaris. " ' |(^Procefliis e quo fit Osjugale didtum. _T? rfextum. Petrofum, ^^^^^"^^^ ifeptimum. (^Proceffus Styliformis. Meatus auditorius^ &c. Vide^ deOrganis Audit us, Pr^l. XXV. Foramen odlavum. ^p, J'nonum. Occipitis, ^ or m n-^ decimum, vel magnum. ^Apophyfes duas. Foramina qucedam Innominata, Pr^ledio Quarta. T>e OJflbus Facie'h & Maxilhrum^ &:c. OS, Nafi. Unguis, — - ductus ad Nafum. Planum. Mal^, vel Zygoma. Palati, Foramina. • Vomer. Sj^ongiofum ^ feptum Nafi quid. C Alveoli. Superior, < Foramina. ^Antrum. rCondyloides. CProceflus cunda. ProcefT. dentatus. Obli- J fuperiores. • qui (^inferiores. fus "^ Spinal es bifurcati. TranfverCperforati/ ^< Dorfi 12* Lumbo- rum. 5* C CO Sacri 5j vel6. partes anteriores fpongiofe. r^M-v • Cfuperiores Procef-)°''^''l"'iinferiores. fus ) Spinaks. (_Tranfverfales. f Spinse. < Foramina. C ProcefTus obliqui fuperiorcs, (^Coccygis 4, vel 5. Cofe i2.|^^'^^J-^jApC)phyfes, & Sulci.. r OlTa Pedoris, plerumque tria^ Sternurn < Cartilago enfiformis. C Cartilagines ad Coilas, Os Hyoides. Pr^ledicl STL LJBUS. 3JI Pr3ele6tio Sexta. OS, Clavicula. rAcetabulum. Proceilus*} ,* (^ Acromion. Scapula, '< ^ n C Superior, ^^^^''tlnferior. Spina. LBafis. Humeri, '^ rCaput. Apophyfis fuperior. Sulcus. Apophyfis -< . ^ ' >inferior. ^Sinus. TTi ("Olecranon. ^^"^'tProceiTus Styloides. Radius, — — Tuberculum. Metacarpi 4. Pollicis 3. pigitorum 12, PrselediQ 3JX SYLLABUS. Prasleitio Septima. TOe OJJibus artus infer ioris. OS, r^.. r Spina. , . , Ifchium-Proceffusi'^^^^"^- Innominatum,^ (^acutus. j Pubis. I Acetabulum. ^Foramen. Caput. FemoriSj Trochanters ^^ ' <^ minor. Linea afpera. Apophyfes inferiores. Patella. Tibia, Apophyfes. Fibula, Appendix-[[;;P;^^^^^^^ r Aftragalus. Calcaneum. ^ Cuboides. ^^^^^ 7-< Naviculare. I rmajus. I^Cuneiforme i medium. C minimum, Metatarfi 4. Pollicis pedis 3. Digitorum pedis 12. Selamoidea. Praeleclio SYLLABUS. 3n Praeledio Odiava. ^e Ligament is ^ & Cartilaginibus Cap* , ta offium inveftientibus^ & Glandulis Of- Jium-i jun&uris infervientibus : Etiam de his quibus Sceleton Viri^ & Fmmin^ Fxtus^ {§ Adult i differmu. 'Ligamentis in genere. 1^ )Ligamento terete. Cartilaginibus in genere. / Glandulis junduras lubricantibus. Aa ENTE- 3J4 ENTEROLOGIA. Pra^ledio Nona. jD^ quibufdam Tartium externarum inte* gumenttfque ^Tartibus conjiituentlbus. Scrobiculus Cordis. Regio Umbilicaiis. Hypochondria. Hypogaftrium* CcBtercB partes epstern^ propriis Trcele^ionibus funt demonftrand{E, Cuticuk, Reticulum mucofum. P « C Papilla Pyramidales, -Ungues. '"^^^^'iBulbi, unde procedunt Pili, Glandulse miliar es, vel fudoriferse. Membrana adipoia. Mufculus. Tendo. Os. Cartilage. Ligamentum. Pra^Iedtio Fibra. Nervus. Membrana. Glandula. Arteria. r Ladeum. Vena. Vas < Excreto- Lymphffi- ^riuiB. du^us. SYLLABUS. 35 J Pra^leftio Decima. 2)^ Membranis totius Corf oris.- Dura Mater. Pia Mater. Mediaflinum. Pleura. Peritoneum, ^c. Prseledio Undecima. ^eGlandulisfalivalibusy earumq\ du&ibus. Parotides, vel Maxillares fuperiores. Maxillares inferiores, ^earurii dudus, Sublinguales. Tonfill^, rBiiccales. Membrana Glandularis oris, ^ ^ * cujus Glandulse nominan- tur Linguales. Fauciales. Palatinse. i^Uvulares. Prseledio Duodecima, ^e^uStu Alimentali, ^ Membranis in Abdomine. Peritoneum ■ ■ ■" Vafa Umbilicalia. /^^ Prael. xxii. A a 2 . Omentum, 3 J 6 S T L L A B U S. Omentum, S ' ^inferior. lI Burfa. CEfophagus. rfiniflrum, Cardia. Ventriculus, — orificum < dextrum, ubi circulus C fibrofus. r Duodenum, Intellina tenuia,< Jejunum. C Ilium. I n- f Colon, ubiValvulas ad ingreflum. «^ < Csecum. ^'^^^^ iKt&nm. In omni parte duEtus Aliment alis eft notanda r externa, Communis. Tunica < media, Mufcularis. C interna, Glandulofa, Villo obdudla, r-VentricuIo flaccido, Rugse. Tn^T *- c tenuibus, Valvulse Conniventes. An Nervo brum. 3 rum par Ventriculi 2 an- teriores. 6■^ ^ I feu Auditorium. ^feu vagum. I AcceiTorius Recurrens* ^1 Cerebellum, — ;— Proceflus vermiformes, 0 1 rt. • CCorticalis cinerea. ^^^^^^^^^Medullaris alba. Septum lucidum. ^ . C Radices. Formx,^Crura. rPlexus Choroidcs. Glandula Pineaiis. Corpora ftriata. ThalamiNervorum opticorum Nates. vTeftes. rad Radices Fornicis. Foramen < anterius. Cpofterius. Ventriculus tertius. ^T ' 1 CValvula. Ventriculus quartus.^p^^^^^^j._ ^od de Cereiro fupereftvix notatu-indignumjudico, Prseledtio Decima Nona. 5Df Medulla Sflnali t§ Nervis fajfm in Corf ore differ fis^ Meninges. Medulla Spinalis^ Cauda Equina. Medulla ST LLABU S. 363 Medulla Spmahsj p,restSacn6. ^ Brachiales. Cubitales. Digicales. Intercoftales, ^ V Canticus. Tibiales. Digitorum pedis. $unt plurimi ex his oriundt^ t^ pey Corpus undique difperfi ; ^ apartibus quibus fuhferviunt mmi- nantur. Prasledio Vigefima. ^eTartibus^rinariis^ ^ Organis gene* rationis in Viris. "Arterise Renes, < Glandulse. Papillae. Tubuli Urinarii. Pelvis. Glandulas Renales. Sinus, Ureteres. r Externa communis. Vefica ^"""tTunica)^^^^^' Mufculus detrufor naria, y j urince, C Interna. Tcftcs, SYLLABUS. Teftes, ^ rCommu-C externa. Cutis. pes, '(^ interna, Dartos. Tunicas "N r- externa, Procef- / -ra • 1 fus Elythroides. ^P'"°P"^jinterna;AIbugi- C nea. ^J^^^^^l'spermaticae. Corpora varicofa. ^Epididymes. Vafa deferentia. Veficulae feminales. Proftatae. (Prasputium. \Cn\ « ^Froenum. I Lr an jS^Qj-poi-a cavernofa. (^Glandulae odoriferas. Crura. Corpora cavernofa. '^ Septum. I I Connexio ad OfTa pubis , (/. e.) Liga- I f mentum fufpenforium. ; I r Corpus cavernofum. [{^Urethra. <^ Roftra Gallinaginis. cMembrana Glandulofa. Mufculi: Fi J^ Prsel. xxvi. Penis Praeleftio SYLLABUS. 365 Pr^eledio Vigefima Prima. 2?^ Tart thus Generationis Mulierum, ' rMons Veneris, Rima Magna. Labia. Nymphse. Externse, ^ TGIans. (^ Corpora cavernofa, ^Meatus Urinarii exitus. r Hymen. NCaruncuIse myrtiforme^. Vagina, .^Rugse. J Glandular, ( Lacuna. Ovaria ArteriselV >Ven^ |fpermat.cs. Corpora varicofa. Ova. Pricledio Vigefima Secunda. 7)eF(Btu inVtero^ cum Membranis^ Sec. r Chorion, Membrana-? Allantois, C Amnion, Humorei, 366 S T L LA B US. Humores. Placenta Uterina. r Vena. Vafa Umbilicalia, < Arceri^. Dudus venoius. cUrachus. Foramen ovale. Du6tus arteriofus. Pr^le^tio Vigefima Tertia. 2)^ Organis TaSfus^ Gujius^ & Odoratus. Tactus. Papillse pyramidales in Cute. Vide PmL ix* Gust us. Papillse pyramidales in Lingua. Odoratus. Membrana Glandulofa, & Nervea, pafllm in- dudla in Laminas Nafi, commune Os fpon- giofuki didum. Prseledio Vigefima Quarta. ©^ Organis Fi/us, Palpebrae cum Ciliis, & Superciliis. • Caruncula lachrymalis. Duftus lachrymales. Tunica SYLLABUS. 167 rConjundiva. Cornea. Tunica < Choroides. Uvea. Retina. LAranea. ProcfifTus Ciliares. Iris, Pupilla. r Aqueus. Humores, < Vitreus, cCryftallinus. Pr2eIe<5l:io Vigefima Quinta. T)e Organis Auditus^ Auricula, Meatus Auditorius,— Membrana Glandulofa. Iter ad Palatum. Tympanum. Membrana Tympani. Veftibulum. ¥ i. - I- CCochleao Labyrinthus. |canales tres femicirculares. r Incus. ^^^^'WaJleoius. (Ofliculum quartum. Texternus, Tympani iaxator. Mufculus Compreflbres, Re6ti, — flexores. Tranfverfales. Cremafteres Teflium. Ere6tores Penis: Acceleratores Urinse. Eredores Clitoridis. Sphin6ler Vaginae, • Sphin6ler Ani. Levatores Ani. Prseleclfo S T L L A B U S. 369 Pr^ledtioVigefima Septima. T)e MufcuUs Faciei^ Oculi^ &c* Frontis. Occipito-Frontalis. Retrador Auricula. Palpebrarum, Orbicularis. Ciliaris, eft port to prions. Aperiens Palpebram fuperiorem rectus. O C U L I. Elevator. Depreflbr. . \ Addaftor. Abdudlor. r^t,r Ciiiperior, fcu TrochleaHs. Faciei. Sphindler Oris. Elevator "> Labii fuperio- ^Dilatator ) alarum "Depreiibr 3 ris proprius eft*^ Conitridor 3 Nafi, De^r^effor}^^'^^''^'''^"^''"^^ proprius. Elevator 7 j u- • Tx r^ >Labiorum communis, iJepreiior ) Zygomaticus. Buccinator. Platyfma Myoides* ' B b Pra^ledio 370 SYLLABUS. Praeledio Vigefima Oftava. 2)^ Mufcults OJJis Hyoidisj Lingua^ & Laryngis. Ossis Hyoidis. r- ^ -^u^ -J ^' Hurfum, antrorfumque. . Geniohyoidei, ) ' ^ Stylohyoidei, furfum, retrorfumque. Coracohyoidei, deorfum, retrorfumque. Sternohyoidei, deorfum. Lingua. Geniogloffi, furfum, antrorfumque. Stylogloffi,- furfum, retrorfumque* Ceratcdoiri5> 1 Bafiogloffi i-,'^^^""'"- Laryngis. Hyotliyroidei -elevatores y Cricoarytoe- C poilici, 9 . ^ a noidei, 1 kterales.X^' H^T""^^'" Thyroarytoenoidei, ^ ^^^ ^ ^^^- ' Arytcenoidei-::::claufores. Pra^leftio STLLABUS. 3.71 Pr^ledio Vigefima Nona. 2)^ Mufculis Maxilla inferior is^ Tha^ ryngis^ & %)vula. Maxilla inferioris. Digaflricus, depreHbr. Mafieteres, ") Temporales { , ^ r ^ ' >elevatores. Pcerygoideii^^f^H ^^ l^internijj Pharyngis. Stylopharyngei, dilatores. CEibphagei,'- conftridlores. Vaginalis Guls. - UvUL^. ■D^ n. 1. 1- • Cexterni.-"^ deorfuni. Pterygoflaphy]mi|j^^^^^.; ^^^ GloiTofbaphylini. Pr^le6lio Trigefima. T^e Mufculis Clavicula^ Scapilie^ Hume- ri^ & Cubiti, C L A V I C U L .^. Sijbclavius. Scapula. . Trapezius retrorfum. Elevator. Rhomboides, furflim, retrorfumque. B b 2 Serratus 7t S T LLA B US. ^ ^ ("major '>anti-rantrorfum, furfumque. (^minorj" cus, (^antrorfum,deorfumque, Pe6boralis, antrorfum. Deltoides, * 7 r r Suprafpinalis, J ^ ^ ' Infrafpinalis, retrorfum. Teres -^ • I retroQcor— \mmor: eft por Mttfc, infrajp.y r LatilTimus Dorfi. j ^ ' Coracobrachialis, furfum, extrorfumque. Subfcapularis, introrfum. C U B I T I. Biceps, __ Ipiexores. Brachialis,^ Triceps, lExtenfores. Anconeus, J Pr^ledio Trigefima Prima. ^eMufculisVolaJManusj Carp, ToUicis^ T)igitorum, & Radii, VoL^ Manus. : 1 almaris|^j.^^.g^ ^^^ caro quadrata. Carpi. ^. CRadialis, Flexor ^Ulnaris. / ^ \. CRadialis, feu Bicornis.. Extenfor.^y;^^^j^_ Pollkis, S T L L J B U S. 373 POLLICIS. rprimi -^ Extenfor ^ fecundi >internodii, Ctertii J pi^^Qj. Cprimi, & fecundi Offis, (^tertii internodii. Adduaor. Abdudor. DiGITORUMa Perforatus, fecund. -^ Perforans, terc. >internod. flexor. Lumbricales, primi J c Communis. Ext enfor <^ In dicis . cAuricularls. AbduftoriP"".™ .Idigiti. 4 minimi 3 ^ Flexor OfTis Metacarpi minimi digiti. Interoflei, extenfores, & divaricatcres« Radii. Supinator 4" l^'^g^' ^^^^' ^^^^^ ^^^iti. ^ (^brevis. • Pronator^ ^''^^j* ^ , j^^uadratus, ^ Praslculid 374 SYLLABUS. Pr^ledio Trigefima SecandaT 2)^ Mufculis Captis^ © QoUu Capitis. Maftoidei, -\ ^ n-^interni-J -^ >flexores. Claterales — utrinque.J Colli. Longi, flexores. Scalenir Intert ranfverfales . Capitis. Splenii. ^ Complexi. \ ■R fk' J^^^J^^^s ^extenfores. ^ ^ (^ minor es f ^^^^^jtinferiores rotatores. Colli. ej Interfpinales 3 Spinaies ^ Tranfverfales > extenfores. Praeledio Trigefima Tertia. , ®orJij Lumborum^ & Coftarum. D O R S I. Sacrolumbales ^ LongifTimi. > extcnfores. Semifpinales. V Lumhrum SYLLABUS, 175 L UMBO RUM. Pfoas parvus, ?itxor fcepe deeft, Quadrati, utrinque. Coccygei. COSTARUM. o ^. Cfuperiores,') n- . Clevatores* S^'-'-^^'iinferiores;|P'^'^'"ideprefrores. Intercoftales^ . ^^ ^-^ S-levatores. (^interni,3 Triangulares, K^nftriaores. Diaphragma, J Praeledio Trigefima Quarta. 1)e Mufculis Femoris^ ^ Tibia > Femoris. Pfoas magnus, "J Iliacus internus,/ a Peftineus, Mexores. ' Triceps, j rmaximus,^ Gluteus } medius, > extenfores. t minimus, 3 Pyriformis, lfg„ ^Iliacus externus, ") Marfupialis, J, t Obturator internus, ( rota» Quadrat us. ('tores. Obturator externus. • j TlBI^. Membranofus,' extenfor extrorfum. Sartorius, T'c - ^ r Gracilis, |-exor introrfumque, Semitendinofus, ') Semimembranofus, ( n Biceps, . 'Mexores. Popliteus, )_ • g K^etus. 37^ STLLABUS. (.1 Crureus PraekdioTrigefima Quinta. ©^ Mufculis Tarji, Tollicis, & "Digito^ rum Tedis. Tarsi Musculi. Gaftrocnemius externuso Vhntm^^ f£pe deeft >extenfores. Gaftrocnemius internus, i ^., . T Canticus, — flexor >"• ^ ^ Tibialis-^ pofticus,_extenfor j^inforfum. Peroneus^ , ^. ' >-extenfores extrorfum. PoLLicis Pedis. Extenfor < , &V ' (^brevis. T^, Clongus. F^^^°'" ibre?is. Abdu6lor. Addudor. DiGiTORUM Pedis. Extenfor i'^'-^S"^- (^ ore VIS. Interofiei— extenfores. Perforatus, — fecund, j Perforans, — terc. Mnternod.flexores. Lumbricales, — prim. > Tranfverfalis Pedis conftridlor. F I N I S. x.^*'t o>^ ; COUNTWAY LIBRARY OF MEDICINE A QM 21 .CU2 1726 RARE BOOKS DEPARTMENT