The economy of the animal kingdom, considered anatomically, physically, and philosophically

471쪽

itself with filioso nervus above. Morgagni obseruod three nervos descending on the lest fide, one creeping up by the postorior part of the carotid artery Where it enters the receptaculum, the others by the anterior pari, and running into iis foramen' Advers. Anat. Vi., Anim. 24); so that the nerve is reflectodround the posterior paris, lies under the carotid, and creeps Within iis proper stud adscititious coat, and so passes into thecranium. It comes Out under the Eustachian iube, betWeenthe stylisorm process of the occipiat, and iis articulation Withthe first cervical vertebra, and then passes over the foramina through Whicli the jugular vetiis oti one fide, and the ninth patros nerves On the Other, leave the cranium, Or Where the internalcarotid enters it. All the spinal nerves, except the firsi and the three last, immediately after coming DOm the spinal marrOW and Vertebrae, present litile tumors Or gangliosorm granules, Whicli transmitshort twigs or cords to this intercostia nerve; in the necti, a Single tWig comes Dom each litile ganglion; in the thorax, tWo tWigs, one from eaeli Side Os the ganglion; Only one again tu the lumbar region. Os ali these the great and common nerve is

tebrat column, beside the transverse apophyses to the last lumbar vertebra, and then in front of the sacrum. During this passage, it expands here und there into gangliosorm bellies, asit did immodialsely under the cranium, into one On the lest sidehigher and largor than the rest, Whicli is iis superior cervical ganglion, and has another similar ganglion corresponding to iton the right fide, but Whicli in many subjecis incliues cedit totho test. Opposite the fixili or sevenili cervical vertebra, this nerve agnin mines a similar station, and On both sides e largos into a gangliosorm plexus, called the inferior cervical; as SOOn asit reaches the dorsat vertebrae, it has another plexus called thethoraci c. From this potui it descends Without any 8Welling ordiverticulum, into the abdomen aud as sar as the lotus, Where it again bugins to expand in the lumbar intervertebrat spaces re

472쪽

it rutis upWards through a foramen into the cranium, fixing tooth and nati upon the carotid. Thus it communicates With ait thenerves of the head, as With the sirst, second, third, Durth, and

seveniti, by means of the fifth and si xth; With the seighth, ninthand tentii, by means of iis ganglion; und With ait the nerves Osthe body, or With those of the medulla spinalis doWn to theos coccygis. Lancisi divides this great generat nerve into a Superior, inferior, and vertebrat portion. So far of this nervo

generically: it Would be tedious to pursiae it through ali iis Windings in the provinces of the bOdy.479. From the soregoing description it is evident, that this nerve has the universat chargo of the body; in that it

473쪽

transfusos and dispenses the spirituous fluid und nervolas juice QVe Where, so that both the nervos and muscies, and the vetus and arteries of the body, and even of the heud, Rre never destitute of it, Or consequently of their activi ty and liso. And this nerve can never sali of this suid, because it has a Desti origin atevery potnt of the spinal marrow, and is hept in the stream Osthe animation of tho brains and medullae. Whicli is the rea-SOH Why, WhereVer any natural motion prevatis, it associales th the par vagum to form retisorm plexuses; and eSpeciallyabout the heari, into whicli it pours nervos abundantly Dom iis ganglia. Thus it appears, that this nerve arises from the medulla cerebelli, and is the vicogerent of the cerebellum in thebody. But to come to detulis. 480. This nervo has the universat charge of the body.-Forit approaches and onfers nil the viscera of the body, both in the epigustrio and hypogastrie regions; and even the VeinS, great and smali. And eithor it invites the Derves into Someos iis ganglia, or associates them to it in some reticular pleXUS, or otherWise joins company With them, or else climbS up OVerthem. From Whicli it folioWs, that it exercises some universalcharge; and for this reason it Was that Wiuslow tormed it thogreat Sympathetic nerve. It appears to have this charge, 48I. In that it transfusos and dispenses the spirituOuS fluid and nervolis j uico everyWhere, so that both the nerVesand muscies, and the vetus a d arteries of the body, are neverdestitute of it, or consequently of their activity and life .-Τo this ossico it is dovotest: as Wo may infer, I, Dom itS multiple origin; for it is horti Dom ulmost res many WOmbS,

certainty and expedition 1 rom pollit to potui, and Whicli ganglia

474쪽

to Which Whon it has thus lent iis fluid, or rather added iiseis lateralty n. 567 , it osten runs out again into other pleXUSes, toprovido ali With fluid cither Out Os What remnius, Or else aneWfrom iis origin. 482. It distributos iis fluid also into the nerves and muscies of tho head and iis organs .-In the description atready given Osthis nerve, it is sileWn that there is no nerve of the body, and DO nerve of the hered, that it cloes nos communicate With, and this, visibiy, Oulside the vertebrat theca. That it communicates also by contact of somo Lind with Dearly ali the nerves of the

os cerebrat nervos performs an Ossice in this superior region almost similar to that whicli the intercostat persorius in the lowerregion, and acts there as the great sympathetie Of those nerves, and the regulator and dispenser of the liquids. I mean iis portio dura; for it goes to ali the nerves of that region, becauseit goes to ali the organs of the senses. This sis th pair arises Dom the tuber annulare, Whicli is a thalamus made up of sibres Dum both tho bratus; and it passos immediately after iis origininto a litile ganglion, in order everyWhere to dispense the received liquid in the fame maniter as the intercostat nerve diS-

475쪽

pensos it in tho body. Into this nervo, and ni the samo time into the fixili pair, floWs Our intercostes nerve, but nos vice versa: hunce through the medium Os these it is able to communicate a large abundance of iis liquid to ali the nerves of thelidad. Diat this generat nerve of the head does not communicato With the intercostia Derve of the body, because it could notjoin With this nervo without a loss of the liquid designed sor themost nOble Organs os the senses. That the intercostat nerves οWs into tho sisti, and fixili patrs of nerves, but not vice verSa,

may be inferred Dom tho laci, that it is nos continuod Domthem, but rutis into them ut a very acute angle, being like agrast upon them ; but stili more evidently Dom this, that is thenotion Os each of these nerves be granted, or the eXtension and remission in accordance With the animations of the brain, fas Surely must be the case in that region,) then Were they inter-

taneou8ly With the Other, and they Would reciprocatly recede and Separate, Whereas they noW reciprocatly approach. 483. And this nervo can never fuit of this fluid, bucauso ithas a Desti origin at every potnt of the spinal marroW, and is Lept in the stream os the animation of the brnins and medullae. -For every time the brattis animate, they drivo out their fluid into the fibros and Derves; much as the heari, at every systoleand diastole, drives out tho blood through iis vesseis ; for everysibre has a cortical spherule prefixod to it, to serve as a litile beari sit. 177), and which, as it animates, Or is expanded and constricted, drives out iis fluid through the fibro continuous Withit; helice into ali the fibres generat ly, When the brattis and the medulla oblongata and spinulis animate generat ly. We inti- maled above n. 283), that this animation is synchronous Withthe respiration of the lungs, although We have not yet proved the potui as iis vast importanco demands. That the intercostulnerve is placed, SO to sponti, in the stream Of this animation, is Very clear, 1. From the multiple origin of this nerve, Whichis it is not actually borti Dom ali the fibres of the spinal marrOW, 3 ut it arises hom them a ter contact; sor tWigs are sent Out toconstitute it, Dom ali the vertebrat foramina: hunce is it derivesanything by this Way froin the spinal marroW, it must likeWisebe in the stream os iis motion, and is so it must also bu in that

476쪽

of the cerebellum and cerebrum; sor the two Streams are Cesn-cident ; much more must this bo the casu, is the spinal marro be res it Were tho appendix and prolongation Of the medullarySubstance of the brains, to Whicli it associales iis oWH proper medulla excluded or born Dom iis own cineritious substanee; there- fore that Whicli is the cause of the cause is the cause also Os thething caused. 2. And the more so, as We shali sOOn undertineto SheW, is the intercostat nervo originatos frum the cerebellum, or is a medullary process of the cerebellum, descending along the Spinal marroW, after contuet With the fibriis of that marroW,iSSues through eaeli foramen out of the theca, to constituto this nerve, by Whicli means it is Lept in the stream of the motion of the cerebellum, as Woli as of the spinal marrOW. 3. This nervereceives a cord DOm ench hordisorm ganglion that lies just out of the foramina of the vertebrae; into every one of Whicli ganglia the spinal marroW immediately passes With iis fibres, iis fascioles of sbres, iis pia aud dura mater, and iis blOOd-Vesseis. Henee also the action Os the spinal marrow passes into the be- forementioned litile ganglious, und Dom these Wholly into thenerVe made up Os the coriis sent Out there rom: and this, stili more evidently in the dorsal region, Where the spinal nerves gooiit, for there it receives tWO cords DOm the gangli Ons, Whereas everyWhere else it receives Dom them Only One; the reasonbeing, that the spinal or dorsal nerves aet immediately Uponthe museles of respiration, Or the intercostat muscies, and arethus in the very region Where the stream Of this motion is, in-asmuch as the respiration of the lungs is synchronous With the

animation of the bratus. 4. Add to this, that iis bighest ganglion in the nocti is attreched ut one enu to the eranium, and this is tho ganglion into whicli tho medulla of the cerebellum sirst flows; so that the intercostes nervo begitis to receive iis motion immediately Dom this pollit, a motion Whicli is either in the very stream of that of the medulla, or else is in directaecordanee With it. 5. That the casu is so, might be inferredalso Dom the fact,-that this nervo insinuates itself in various Ways into ali the branches of the agygos, and into the nZygositself, and entWines them like ivy; and stili more clearly fromthis circumstance, that the moment the carotid enters the Cranium, this nerve ut Ouce ensolds it, creeps belWeen the proper

477쪽

and adscititious coat of this artery as sar as the receptacles Ofthe sella equina, nor Separates Dom them excepi ut the base of the brain, Where this vesset, hitherio in tramineis, it finalty de- livers Dee to iis moving cause. All this is to the end, that this nerve may be in the Same stream os motion as the internalcarotid, Whicli suffers itself to be acted on by the brain alone, and by the motion to Whicli the brain disposus it. It may bementioned also, that this nervo enters the tunic of the jugularVein. 6. Since, therelare, the intercostat nerve is Lept coΠ- Stantly in the stream of the motion of the bratus, it solioWs, thatit derives froni them a large abundatice of fluid, Whicli it distri

485. Τhus it appears, that this nervo arises Dorn the medulla cerebelli, and is the vicegerent of the cerebellum in the body.-Νo anatomist indeed, even had he the eyes of a lynx, could by tracing the fibres, give oculis demonstration of the saei, that the cerebellum sponds itself on this nervo. We must there- fore adopi Some Other method os proos, or elso the truth of the matter Will remain in perpetuat obscurity. The method Ιmean, is that of examining the ways that the nerve acis in iis extremities, and then comparing them With the distinet characters of the bratus. For, I, it is perfectly Weli linoWn, that When the cerebrum, or even a portion of the medulla oblongata, is Sticed, laid baeli, or compressed, the vital motions of the body, as os the heart for instance, do nos cense; for according to the experience of Vieussetis, the heuri bestis almost as be re, Neurographia Universalis, cap. XX. :) but vhen the cerebellum iS cui,

478쪽

Sticed, or compressed, the pulse of the hestri immediately Stops; proving that the spirituous fluid procedding to the intercostes

nerve is immediately intercepted, and that the nerve cannot Teceive a fresti supply Dom either One origin or the Other. Τhus the cardiac muscle is deprived of the poWer os action, and ConSequently dies. The case Would be OtherWise is the nerve consisted of the fibre of the cerebrum, medulla oblongata, or medulla spinalis, Dom Which, even on the decense Os the cerebellum, neW life could nevertheless sow in, and the motion os the hearibe continued. But this argument only illustratus but does notprove; lar When the cerebellum reposes Or dies, the spinalmarroW also is quiescent, sO close is the connection betWeon the two in most laud animais), and thus is the Derve arose Dom it ei ther, the stream os motion Would lar a Similar reason be intercepted. But, 2, this nerve it is that has the universat charge of the body, just as the cerebellum; the case is disserent Withthe cerebrum, Whicli has the particular charge Ospecialty of allthings, by means of the medulla spinalis and oblongata; hetice

this nervo has an Origin accordant With iis nature. 3. And this nerVe DCVer apprORehes the tunies, organs and Viscera, that possess sensation, Or the muscies that are excited by a previous exercise of the Will, excepi only so sar as to communicate iis fluid to the nerves of sensu, and to those that excite the musciesto action in conformity With the wili. Not so the nervos thaturise Dom the medulla oblongata and medulla spinalis. Fromthese circumStanees We have abundant evidetice to fheW, that thenerve germinates 1 Om the medulla of Such a viscus n8 ΡOSSESSOS DO particular Sentience, and eXercises no particular Wili; conSequently, that it arises froin the cerebellum. To enumerate allthe viscera and their membranes, ali the muscies and gland8, to

entered Where there Were motion and sensation, into the Same

I also found severat other nerves of a disserent family determined, producing this effeci; in such cases, therelare, the inter-COStat nerve entered sol ely for the purpose of vivis ying them Withiis fluid. This is very clear Wheu me contemplase iis disserent

479쪽

modos and laWs os acting; as in the ceSOphagus, Where the voluntary motion Os deglutition is converted into a natural spontaneous motion : and in the larynX und bronchia, Whose motions agnin partake of natural spontaneity; and most plainly in

is the most nobie os spring of the cerebellum, and is iis vice- gerent in the body. 4. Is, then, this nerve arise Dom the fibres of the cerebellum, and those os iis frst process that embraces the stem of the medulla oblongata above the fourth ventricleand under the nates, and then descends, We must in this caseassent to the opinion os Lancisi, Who derivos the first origin Ofthis nerve Doni the two protuberances called the testes and nates, De Motu Cordis, Ac., prop. 48), Where they are connected Withthe peduncies of the pineat gland. Be this as it may, Whetherit derive iis origin Dom these fibres, Or Dom others, it Originates Dom sucti as floW dOWnWard. See also n. 490.486. Besore dismissing this nerve, Ι must explain in generalhom it and the par vagum associate With the arteries and Veius, and reduce them, and ali other paris, to the universat motion Ofthe bratus. The animal frame, and especialty the human, is a machine impelled by most diverse motions, nil of Whicli never-theless return through a certain Orbit to their principies, in

480쪽

Whole must be confusion utiless tho skill of the mechanio QOmbine the paris and regulate the whole. It is therefore provided,

Corollae, and webs discriminaled by various thronds, that ali thesaris may agrest anil combine With precision aud regularity. Thus

ciating harmony is alWays possibie, particularly by means of the purer fibres and fluids, Which being more perfeci than the

intimately, and glues itself to the membrane; sin alty it entersthe inmost membratie, and iis doors and iis bolis. Τhus it