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So that tho corobellum onjoys determinability over the reciprocations Of animation, just as much as the single masses of the cerebrum. And honoe it is that tho cerebellum piso animates synchronousty With the respiration Of the lungs. For Wherevertho cortical substance is so fitted into iis organ as to be expan
fame Will. There is there re a voluntary animation of the cerebellum in generat, Wheu there is a voluntary animation Ofthe cerebrum; as during the dan Whenever there is good reasonthat thu Will should bo carried forWards into aut by a generalaid. But at night, When no particular action Os the cerebrum subdistinguishos and gives perspicuity to the generat action; orWhen nothing comes Dom the externat organs to iis distinet consciousness and intuition, it appears as is ali voluntary determination had consed in both these viscera. But there is a Want in ali paris of the animal system, Whicli Want in fact is one of the causes determining the Will,) that necessitates the car
ing round of the spiritu us suid sin Whicli tho liso of the wholo
163. And how by the two medullae; sor in eaeli a similar animable and expansito substance resides; and from the disposition of this substance, and of the fibres proceeding Dom it, Wemay conclude, that these medullae, While they are subject to a
common excitation Dom their oWn proper cineriti Ous Substan es, are excited also to their animations and determinations by both the cerebrum and cerebellum; by the cerebellum to common animations and determinatioris, and by the cerebrum to particular Ones. Τhus the voluntary animations and determinations of the cerebrum are transferred to the medullae; and by repeated exercise and frequent use, a re ut last rendered familiaranti as it Were naturat: and this, principally by means of thecavities and ventricles : for the medulla oblongata arises homthe corpora striata and thalami nervorum Opticorum, Whicli constitute the Wali of the superior ventricles and enclose thu
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third ventricio; and it also obtaius fibres in ali directions under the solarili ventricie. And the medulla spinalis, divided as it
Were into tWo semicylinders, has iis moveable and expansibio cineritious substance at iis axis, near the fissuros and cavities
tions of the cerebrum are transmuted into the Semblance of Datural determinations. Ρari I., n. 574. This is illustraled by the braitis of the more imperfeci animais, particularly birdsand sishes, Whicli the moment they are halched or born, at Once enter On the fuit possession Of their nature, knoWledge, and peculiar laWs of action, to Whicli they bocomo eastly habitu-ated Without any previous determination os a distinct Will. In the more persect red-bloOded animais,V says Malpighi, and inali tho largor fishos that have hitherio come under my notice, Iliave invariably observed this cineritious substanee, termed the cortex. It is not Only spread round the brain externalty, like
the bark or cortex os a tree, Whicli Serves merely RS an Outer OnVelope, . . . but in red-blΟOded animais a portion of it is placeduround the Outermost appendages of the corpus callosum; therem aining portion being dispersed about in the ventricles, particularly at the Origin of the spinal marro , Where you Will findlittio Dingo-like pieces of the medullary and White substanee Ostho brain disseminated and enclosed. Ρari II., n. 82.) But these remariis Will be confirmed by innumerable proose in the
164. Also horo in the di erent kiniis of brute animais. As itis not our design to trent of this subjeci specifically, We here observe only in generat, that this cortical substance is disposedand distinguishod in a peculiar manner in the bratiis of irrationes animais, and exactly combined and fitted to the distino-tivo actions and life of each; and that it is supplied by sanguineous current8 quite disserently tO What obtains in human bratus. As respecis the one potnt of the influx of blood, it is mund that in the bratiis of brute animais, it is With difficulty that it is re-strained Dom rushing in at the stightest instinci and intimation,
and suffusing the cortices substance; so that their determinations, Whieli are analogoUS tO Our Voluntary determinations, result necessarily DOm the reigning temperament of their purerblood, froin iis state, and Dom iis condition as alterod in con-
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formisy With the times nud sensons of the year, and with the contingent excitations of the externat senses. on the Other haud, truly human brains have the privilege and liberty of Leepingtho blood out at tho doors of the cortical substance, and hold-ing it at a distance so long as 'he miud is revolving iis rensons; and even os blunting the acumen of the externat organs of Sensation SO far as to provent distinet perception of the objecis presented to them. We shali have Wonderes to relate On these subjecis in the Ρaris oti the Brain. 165. The brain, by this iis facultv and force of animation, --trαCD, a8 we 8aid, a most pure essen e from the invited blood, and transmiis it into the Fbres, as iis delicate appendage8; und psurs On it a new essence, conceived and eaecluded by a high process of generation in the snest wombs of iis substance. The majority of the learned, particularly since Alalpighi, have maintained the opinion, that the cortical substance conceives and produces the Spirituous suid, or as they cali it, the animal spiriis, Whicli theyagree in describing as a pure fluid. This opinion is confirmed by a Vast number of Observations that have been made in thobody, and by Dearly ali that have been made hithorto in thobrain. Whoever considers,V says Boerlinave, the nature Ofthe CorteX, ke., kc. , . . . must jud ge that the medullary sibresare delicate perviolis canais, Whicli receive the subitost os ali tho
fluids of the human body; a fluid Whicli is prepared, Secreted, and forcibly drivon into these pipes by the Wondersul mechanismos the cortex, and so collected Dom every potnt into the medulla oblongata.'' Ρari II., Π. 95.) Malpighi, folloWing Hippocrates, and the sollowers of Alalpighi, Who admit that the brain is a gland not only in bulli biit in pari, agree that this substance, Whicli is fuit os minuto passages, not Only send8 n highly recti-fied humor tahen iis froin the blood as through a fleve into the
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nute globular fluid hodies, are also fuit of yet far more minute Vesseis, than they themselves are. V Ibid., n. 71, 84.)166. This fluid, pure beyoud ali imagination, is not to he
tribute, accident and quality as distinctively belongs to the corpuscules of the earth; for it is the force in form os nature inher mOSi persect Sphere. Ρari I., 11. 638.) Is this fluid bo determined by this substance alone, and turn Out to be the most persect mrce of animal nature, We can theti understanti how iis essence must be elevated above the essetices of the visibio and ultimate Worid, and must be abstracted DOm their proportios. Respecting the rules for this elevation and abstraction, See Ρari I., 11. 648-65 I. 167. But the wondersul ari os nature Whortibu this fluid isolaboraten in the factories of the cortical substances, Can neVerbo solio ed by the minit, uniess it be previousty instructed in the doctrine of Series and degreus, and in the philosophy 0s universals. See Pari I., Chap. VIII.) For this science goes
far beyOnil essecis into causes, D V, even into principies Os RuSes; Where re the conception aud formation of this fluid arus id to be eminent or transcendental. This much, hoWCVer, We may See RS 1 rom asar or in ShadoW, that the proximate cause of iis conception is the SOul's representation of her univerSO,
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idea Whicli umbraces ut ono glanco the state Os iis Lingdom, Whicli ulone is sufficient to cause tho sirst aura of the worid tobe determinod into suci, spirituous fluid most silly correspondi ligio iis Lingilom. For this aura, formed to the 1 Orces of nature in her most perseet sphere, involves ali possibility os applyingilself to overy inconceivable minutia os variety, consequently Osconcurring Willi every assignable determination Ρari I., 11. 604, 635). How much does an idea alone effect in the loWer Organism of the pregnant semate 8 Ρari I., n. 267). HOW muchmore in the highest sphere, or in the principies of causes 8 Andhow much more in the litile factories of the cortical Substanee, Whicli are at Once the organs os internat sensation correspondingto the organs os externat sensation Ρari II., 11. 19l , and corcula or litile bearis, os Whicli a type is presented in the grandheart of the hody, which also is a chemicat organ preparingliquids for composition into blood Z Ρari I., D. 453-457). But I am sorbidden to venturo furthor, test I should say What is littio understood; for having no WOrdS to expre88 my meaning, I should of course bo obliged to betake myself to analogues andeminences, by abstraction froin the things brought out by sense,n case in Whicli even trutiis favor of hypothesis.168. me may thus underfland the course of the circulalion of the animal spiriis; name , that it is from the cortet inlo the universat Fbres, from the Fbres into the blood, froni the blood into the brain, and so back into the cortem. I do not thinii thoro isnny more excellent Or nOble science in the universat animal kingilom than the science of the circulation Os the spirituous fluid; for this fluid glances through every potnt, and continueS,
thing whatevor in iis limited universe. In time and universality, and consequently in excellenee, it far precedes thecirculation of the red blood, Whicli circulation is a comparativelylato discovery); for it is the cause not only of this circulation, but also of the circuits of ali the other humors in the body. And this Ue know Dom the faci, that this spirituous fluid Withiis fibro is ali in ali in the whole and in every pari, and i S thesingle fluid in Which life proximately resides, while in the redblood, and in the essen ces derived Dom it, life resides more re-
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motelv. On this account tho circulation of this fluid dosori es
to be called the cIRCLE OF LIPE Ρari I., Π. 38, 39).169. In ordor that this circulation may begin under theauspices of the brain, it is necessary that every spheriale os iis cortex sit Ouid animate. To suppose the circulation of this suid Without a motive force, and a real eXpansion and constrietion asa moVing cause, Would be the Same as to imagine the circulationof the red blood through the arteries and vetus Without thelieart. Thus unless litile hearis Wore prefixod to est the fibres, nothing Would flow in of iis oWn accord hom the litile arteries, and nothing of iis oWn accord Would soW doWn into the fibros. Therofore the animation of the brain is the primary origin offliis circulation.
170. This then is a circulation Dom the brains, through thesbres, into the blood, and Dom the blood bach to the bratus, and so on : so that nil that is truly sanguineous, distinctly passes gain into tho fibros; thus this fluid does not return throughany venous fibres; and in laci eXperienee knows Os none such. That the spirituous fluid passus Doni the brain, through thesinuses ut iis base, into the jugular vetus; and Dom the fibres generalty into the vesseis of the body, and thetico in to the blood,
503, 556, 634, and the subject Will be continuod in our succeed-ing Ρaris. The above talios place in ordor that this red humor may acquire the nature of iis parent, and bo the sotars vicegerent in the ultimates of iis Lingdom. Thus and no OtherWisecan the fortunes and condition os animal liso depend upon thenature, ConStitution, determination, continuity and quantity ostho blood. This circle therei ore is draWn Dom an Origin mo8tly
voluntary tuto the natural origin of the heari, and Dom this again into the voluntary origin of the brain; the sirst anillast term os it being, thorefore, voluntary, but the intermediate
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subject to tho decisions and destres of the cerebrum, the salalyboth of the wholo and of the paris Would be endangered; forthe Will could govern the vesset of the state mitti no bellor si illthan accordest With the science possessed by the cerebrum ; the Will and this science HWays proceeding pari pa88u; CODSequently Would ruti it a thousand times an hour among qui elisandS anudangerOuS Shoals ; Wherelare this circulation is exemptest homilio Uilt of the brain as Keil as Dorn iis Selenee, RS SOOn RS OVOrit enfers the body, or the natural circulation os the blood. Anullius We olearly see What is the influx and what the connectionos the voluntary motions With the natural in the body; and
172. IVe may also understand the moments of this circulation ;namely, that they are synchronous with those of the respiration of the lungs, which twonder fully concur in promotino anil transfusing this truly animal Dice through the nerves. Marveis indeed occur, -I WOnder they have been unobserved,-in the sold of thenerves. Thus as Soon as the lalter have emerged Dom their natat solis, or Dom the bratiis and their tWo medullae, they passthrough the hody in the manner most perfectly adapted to the expansion and contraction Of the lungs, So that ut the very moment they are inspired by the bratus, they are also dilated by the lungs : and so the injected suid is carrien on hom principiesto ends bu n Wondersui cooperation, and in a rapid Stream, Oras I intimated above Ρari II., Π. 8), is carried on by a commonaid und natural vehiclo through ali the pipes and fibres ; sor itis the nature of the fibres res Weli as of the arteries to be atonco dilated and extended every time they are permeated by thoir fluids.173. We shali have ocular demonstration of the truth of this is Wo trace the nerves, particularly those grand and most generat nerves, the intercostat and the par Vagum, as also theothers, as the brachiat, dorsal, and ischiadic,) throughout theirmagy Wanderings in the region Of the body. For euch of themadapis iisseis et ther to the trachen, or to the bronchia, or to the mediastinum, or to the pleura, or to the sternum, or to the Vertebrae, Or to the ribs, Or to other paris Whicli are called 1ntoplay bu the tumefaction of the lungs; and this, So nicely, that
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the nerve is carriod by montis of each lung into a state Os cxpansion similar to that whicli tho nature of each sbre domands.174. And this is the reason Why the beginnings of the nerves run through nolchus, oue of Whicli is cui in the body of auupper vertebra, and the other in that of the vertebra nexi bolowit, and which nolchos are stted together to form the foramen os
they run, are siluated immediately oulside the notelies, close tothe vertebrae. Why the larger ganglia os the intercostat nerveare also partly affixest belli d the fame notches, and at the Same time beside the larynx, the windpipe, and the ribs. Why the par Vagum and the suid intercostat are transmitted through theneshy part of the diaphragm, Which ΜOrgagni mentions as a remari able circumstance Advers. Anat. V., Anim. 12). Whythe concave lolies of the lungs lie upon the diaphragm, and Whytho diaphragm is continuod and united to the ribs and pleura, the pleura to the mediastinum, and the mediastinum to the pericardium. Why the grateWork of the ribs and of the vertebrae, With the Sternum, the scapulae, and the mammae, is stightly elevatod Whon it is expanded by the inspiration of the lungs, particularly When the natural mode prevatis, as during Sleep, at whicli timo the necessity of renovating the state requires thattho transsux of the fluid through the nervos should not be iu-
terrupted by any voluntary determination Os the cerebrum.175. Thus nos only the nerves that must concur alternatelywith the pulmonary motion, but also the others that are transferrest out of this motion into another, as into that of the heari, stomach, intestines, bladder, liver, or genital members, are Soimmediately brought and applied to these motions, that by their
modiation they glide into similar reciprocations Os eXpansion, as We have Hready observest Of the cardiae nerves Ρari I., D. 54J), and also of the great cardiac plexus. Thus I thiuli We have the reason Why When the chieli Or embryo is excluded, the animation of the bratus conjoins itself With the respiratiouof the lungs, and leaves the society of the heart. See Ρari II., Chap. I.; and fari I., n. 280, Seqq. 176. Sin e this cortical substance resides in the principia of the actions of iis body, and from above contemptates the rest of the
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system as below it, it is necessary that ali thinos in the systemshould correspond to it, eaeactly as essecis correspond lo their causes. Wherefore it is right to attribute to ii, by eminerice,
ei erythino that performs any kind of function in this whole inodom. Thus euch part of this substance may be called by
eminence a muscie. In Order that we may know Whether the Severat cortical substances may fairly be suid to be muscular intexture, and in denomination, We must 1irst en quire of Whata muscle is constructed, and lience by What determined, and What a muscle is. The ansWers to these questions are the premises hom Whicli the required conclusion Will solioW.177. Os What is a muscie constructed, or by What determinod 3-Observe that by the word determine We here meanto construct and to endoW With a form. Α muscle is constructedos motive fibres; and these motive fibres of theirs; and lastly, of the simplest 1ibres, Which by their mutuat connection actually
178. But inasmuch as a muscle is constructed os motive fibres, so there must necessarily be constructing or determinant fibres, by means of Whicli every fibre of the muscle may becomemotive aecording to the mode of the action required. The determinant fibres are, I. The Simplest nervolis fibre, Whieli contatus the spirituous fluid. 2. The nervous fibre composed os
simplest fibres, and heuce itself less simple, and containing the purer blood. 3. Τhe artery, Whicli is the fibro of tho third degrest, or the doubly compound sibre, Whicli contains the rod
succeed eaeli Other in order, and are the determinant Or constructive fibres of the motive Or muscular fibres Ρari I., Π. 594
179. From these premises it follows, that the motivo fibro ostho sirst degree or Order is What is determined by the simplest 1ibro, Whicli contains the spirituous fluid. That the motivo fibro os the second degree, or the white motive fibro, is What is determinod by the less simple fibre, and contains the purer bloOd. And tho motive fibre of the third ordor, or the flesby motives bre, is What is constructed of the vesseis that contain the redblood. But hoW each Os these is constructed or determined, is not the subject Os Our preSent enquiry.
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180. Theti What is a muscie Z-Α muscle is a compages Oscoordinaten and subordinated motivo fibres. A seshy muscle consists of a triplo order of sibres. Α White musele, as Seen here und there in large animais, and throughout in minute animais Or insecis, consists of a doubie ordor : and a simplemuSele consi sis Only of the simplest determinant fibres that contain the spirituous fluid. Thus although it be not a sanguineous Or fleshy muscle, stili it does not Cense to be a muscular fibre. For every fibre is determinen according to the force that it is to exercise upon the subjacent and circumjacent paris. Hence the fleshy motive fibre is to exercise iis forceupori Weights Whicli the whito motive fibro cannot list; thowhite motive fibre upon tesser Weights Whicli the simple motive fibre cannot list: euch being in correspondetice to iis peculiarmeasure of Ueight . 18 I. The question is then, Whether each cortical substanceshould not be callest a muscle by eminence, sor it is constructed of the purest fibres, Whicli contain the spirituous suid, and Whicli are so many least and most simple determinanis. Theseexquisitely sine vesself,V says LeeuWenhoeli, also displayeda red color Where they Were laid One upon another in IVers three or laur deep, Without any other matter interposed be- tween them.' Vari II., n. 7I). And we have osten SheWnabove, that the cortical spheriale is clothed With an infinity os litile stamina, Whicli contain the spirituous suid or tho blood
par excellence; ConSequently that it is a musole more excellentand perfeci than any Other, Or a muscle by eminen O.