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360. With rogard to the sirsi potnt, horo the spirituous suid,
ond iis biood, cassed the purer or simpler blood, are derived fromthe brain, throuyh the chemical oryans and members of iis labora lory, inlo the jugular vein' and thence into the rictht chambers of the hear -We Would here remind the reader, that the object of the present brief remariis is not to explain the mander in Whichtho spiritu us fluid is conceived and born in the cortical and cineritious substanco of the brain; for this mill bu treatost os in Paris IV. V. and VI. Neither is it the object here, to fheW themanner in Whicli this fluid is transmitted into the nerves, and through the nerves into the provinces of the body; for this is the ossice principalty of the cerebellum and of the medulla oblongata and spinalis, and on this again I shali troat in the abovo Paris. But my present Object is, to fheW hoW the purer bio dis derived Dom tho brain iiself the preeminent gland of iis kingdom, and a chemicat laboratory perfeci in ali Organio apparatus) into the jugular vetus, and so into the right chambers of
the heart. But this is a subject of such a nature, that We cannot explain it, Without premi sing an anatomical description of the members of the brain, Which shali serve as a clue to directus in the labyrinth. WhOever examines the anterior and posterior sursaces of thebrain, beginning at the cortex, and folloWing the medullarythreads and strata, through the corpus callosum to the base of the fornix, and thetice through iis roois and columns into thoanterior Ventricles, Where the whole medullary substance thalis employed in carrying doWn the spirituous fluid has iis termination Dear the choroid plexus ;-WhOever also examines thecourse of the spirituous fluid as conveyed Dom this plexus
through the two foramina into the third ventricte, and so into the infundibulum, and Dom this into the pituitary gland, and by it into the receptacles of the sella equina, and at length into the sinuses at the base of tho brain fundi , and stom these
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considor that ali the fibros With tho excoption of thoso that aredeterminud Dom tho brain through tho modulla oblongata into the medulla spinalis, und so into the nerves, und particularly into the last of the spinal nerves) are collected by astoni8hingssexures into the base of the fornix as into a central axis of the medullary substance, and Dom this are disseminated round asSO many rOOis in each anterior ventricie, Where they expire and
exhale their spirituous suid, Whicli is immediately mixed, copulated and tempored With the liquid exuding Dom the choroidplexuses; is We consider again that this suid is noxi conveyed into the third ventricte, through the two foramina, by means of the action and rolling of the corpora striata and thalami of the optic nervos in generat, and of the testes, nates, and pineat gland in particular; that it is again expressed by means of the infundibulum toWard the pituitary gland, Where it is again iniis passage strained, sit tered alid separated, so that only the purer essenee may penetrate into the human pituitary gland, tho rest being projected round the gland, Whicli is moveable and expansibie in the sella equina; whonce it is distinctly determined by the alternate expansite action into the receptacles of the solla equina, and into the sit Orter and longer sinuses; and indoed the more spirituous essenee, Or that Whieli has penetraton the interiores of the gland , is derived through smali sinusus into the long basilar sinus, Whicli is transverse and circular,
stance itself, and heuce into the tortuous belly and ampulla os the laterat sinusos; but that Whicli sol lows tho circuit of the gland, is expelled in to the cavernous receptacles of the sella, and through the inferior basilar sinus, Ahorter Or larger, into the fossae jugulares, and so through the vetus toWard the vortex of tho heart. Nor is there any difficulty arising Dom the small-ness of the transverse anu circular sinus, of the orifice of the longer sinus in the laterat sinus, Or of the rostrum proceedingsrom tho infundibulum and inserted into the pituita gland since nil these passages mutuatly correspond to each other, totho volatilily of the spirituous essence, and to iis rapid sight through pores adapted to iis nature and purity, as Weli as to thequantity of this essen ce expressed Dom the fibres of the brainwhicli cross tho buse of the fornix. This, hoWever, is but a
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compendium of the subjeci; Whon it is properly sol lowod out it
liko tho superior longitudinal and laterat sinu ses, SO they propelthoir liquid in a disserunt manner see above, n. 348); and be-sides this, they propagate it by a Liud of slight expansion audconstriction, and by the assistance likeWise of modulation audmodification; for this spirituous fluid is highly elastic aud mOdisi te u. 100); hunco it must be actualed conformably to iis nature; that is to say, by ali species and degrees of modifica
of the temporal bones Whicli are subject to perpetuat SonOrous vibrations; for they inclose, and insulate, the very regionthat contains the labyrinth, vestibule, and cavlty of the tympanum and ear, together With the inserior curvature of the laterat
tho p est fluid, is isseis carried Over a highly tremulous area; the Shorter Sinus, hoWever, is extended into the neighboring paris, and to the junction belWeen the temporal, sphenoid and occipital boues. The auditory nerve itself, Or the nerve Of theseventh pair, enters the foramen of the cranium, and the Fallo-pian aqueduci or internat ear, almost in the middie os thoisian d; hence the whole of the tremor that pervades it, diffusesitself on every fide at the moment of iis entrance into the cranium ; especialty since the fascicles of iis harder portion are iu-terpolated With the meniux, and the membrane of the tympanum communicates With the dura mater, and the dura mater With thethin substance of the sieve-like multifori cranium sn. 17 I).Τo this eud a tWig rutis back Dom the audito nerve throughthe foramen scooped Out in the petrous bone, and SpreadS Uponthe dura mater. The Eustachian iube also extends to the Same SOurce, SO RS to convey doWn thither the whole tremor received
Same time sends bach somo os iis stamina into the dura mater, and in the form os fascicles, accompanted With a meninX, perforates and lacerates the foramen, and then embraceS and Bu-
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reaches the base, and immediately by continuity carrios ali the tremulous motion, received and collected Dom every periphe , in to the cavities of the fame sinuses. In Order that this contremiscenee may pass immediately into the liquids, ali tho blood of the lateria sinuses enters the Osseous caverns, the interior Iamina of Whicli, is thin, and invested With the meninX, and reaches to the jugular vetus, into Whicli the shorter sinus insi
internat ear, and another Dom the externat, While at the fame
time the artery, Whicli is the third branch bulon ging to the dura
mater, arrives here through the Same foramen. A large quantity also of the cortical substance Overlaying these Sinuses, tO-gether With a prolongation of the dura mater, Whicli is concen-
trased nearly in this region, transmits iis vibrations into everypoint of them. Moreover the beginning of the longer sinus passes Over the trunk of the fifth patri Whicli is hard and sit thosame time sost,' and then traverses and unites ali the organs of Sense, of hearing, faste, Smeli and sight; so that heing actualed by the modifications os ali these organs, it infuses them into the sinus. The sigili pair of nerves, also joining itself With thogreat intercostes nerve, and lience With the nerves of the wholebody, traverses the bed of the inserior sinus, and communicatesto it tho tremulous state of the body itself. NoW in ordor thattho blood of the brain, thus tremulous, and leaping in tune DOm the cranium, may be properly commingled, the jugular
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vuin attracis branches Dom the Whole vibratory contremiscente tract; Dom the scutisorm cartilage; Dom the trachea, to Whichit is attached; Dom the circles and membranes thereos, whichare alWays put in a tremulouS motion by the voice When spenking or singing; Dom the muscies themselves and the region Osthe externat ear; DOm the temporal, occipital and sublinguat region; Dom the region of the os hyoides, by means of Whichtho larynx is associaled With the tongue When speahing. Andsince the mastoid and scalene muscies, and the cervical vertebrae, participate in the vibration of the larynx, the jugular veluderives iis streams Dom this quarter likeWise. Thus ali theseare placed in the fame stream Of undulatory motion, grantingiliat the animatory motions of the brains and lungs are Syn
Hunco it sollows, 1. Τhat this tremulatory undulation consociales the homogeneous paris of the blood, and dispeis theheterogeneous; in Order that the blood may enter the ventricle and press of the heari in a more prepared aud fluid stato; and may commetice the circulation. 2. That more ospeciallythe spiritu us fluid may be impellen to union With the purerblood, in a Way thus conformabie to the state of the bratus; and at the fame time that it may be carriod sorWard to iis out-leis by the expansion and constriction Os the sinuses : and this, both by eoeternat causes, or by the modifications of the Organs of the corporeat senses ; and by internat causes, or by those properto tho brain itsolf whilo it is horno into modifications by themere representation Os imagos. 3. Thus We seu What it is that
externat sensation, the assections of the animal mind, hilarity, gladness, laughter, &c., contribute to promote the circulationof this liquid; and hoW it is that sadness, anxiety, gries, RHdpainful emotions, impede iis course; inasmuch as the formeropen, and the lalter close, the passages through the SinuSes nuderantes bones; sor according to tho experienco os Willis, this fluid pursues iis coursu Dom the pituitary gland through themanilald passages and pores of the cranium, into the laterat si-ΠUSes and jugular vetus. Analome Cerebri, cap. Xii.) 4. Τhus, evidently by means of the trachea together vitii the brains, thel ungs promote the descent of this bl0od, and the current of the sirst circulation, toWard A the heart.
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nary arteries uster their division are collectively someWhat more capacious thau the ductus arteriosus, it does nos therelare lal
tery, Whicli eXperietices considerable resistance in the collapsedand heavy Iungs of the laetus: hetico tho blood greatly dilates that part of tho trunk that is Deo of the lungs, osten mining it Iarger than the storta iiseis; and oesy a smali portion of blood
tery can Scarcely be filled by the forco of any liquid injection;
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lung collapses, and no longer admits the uir. . . . The heari stilli,eais, but in vesti attempis to throw the blood into the pulmo nary arte , sor the lalter is contracted; and in vain undergoes relaXation in order to receive the pulmonary blood into the lestauricie. Both the vena cava and the auriele, as Weli as theright Ventricle and the pulmonary artery, are sWollen With the
bronchia, and 8o accompany them to their termination, that noliuman industry cati potnt out a single branch of the trachea, hoWever minute, that is not supplied by their ramifications. Τhey are associaled by anastomoses in various places With theminute tWigs of the pulmonary artery, With the intercostat arteries, and with those that come Dom the spinal marroW. TheyOsten transmit a branch to the agygos. See Ruysch and Wins loW.' For aster birili the bronchial arteries are in the stream of the motion os the lungs, and of the brians and medullae, as Weli as of the heart. This is the reason of the variety of their
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the Other viscera, and even in the arteries und vetus themselves
mation or after birili, there is nothing more frequent than eXSanguiOUS VESself, Whicli are neverthel ess in continuity withbloOd-VeSSeis, and are Openen or inflamed immediately on theoperation of any external or internat cause, as in the face, Shin, membranes, muscies, and in ali the viscera n. 146 . The samo
phenomenon is displayed by the Ruyschian process of injection, by means of Whicli a larger number of vesseis is frequentlyopened than is ever discernit,te in the living membrane; it is likeWise displayed by the process of maceration adopted by the fame author. A similar law Obtutus With regard to the lungs, Where the red blood gathers excubat in the dilated pulmonaryarte , and is diverted through the operi passage of the ductus
arteriosus into the noria. Stili, in the meantime, a more pure,
volatile, light and elastic essetice is olici ted Dom tho blood thus propelled n. 100 . For When different species of liquids areacted On by one and the fame impulsive force, the more lightand elastic move With the greatest celeri ty; as clearly proved by the phenomena of practical physios, and by the laWs of the motion os elastic hodies. Τhus by the impulsive action of the right ventriclo, the puror blood precedes the rod blood n. 454), Rud penetrates the pores adapted to it, and consequently the
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pulmonary arteries, Whicli are as yet impervious to the rodblood: these it permeates as far as the lest Ventricte, and to-gother With tho blood of the bronchial vesseis sit. 363), adapis and malles straight the passages that the red blood is to traverso after birth. 365. Consequently this purer or Whito blood at this time describes a simple circle, namely, DOm the brain to the right ventricie ; thetice to the lungs, thetice to the lest sinus and ventricte, and thenoe again to the braitis: thus it describes the samo circle that the rod blood sirst describes n. 327-329). In faci, Dr the reasons given above n. 338), the blood cannot in any quantity be pressed then into the descending storta. The braitis themselves likeWiso repentedly demand ali the better blood n. 346 350). Τhus also in the sormation of the body, the purerblood is the second cause, While the red blood is tho third cause n. 272 . The circulation of this puror blood is relatively Simple, prior, and universat n. J46, 148); for it not only ari ses Om the cerebrum, a d is derived through the jugular vetus tuto tho right fide of the hestri, but it is likeWiso derived Domthe cerebellum and Dom the tWo medullae, and through thos bres immediately into every blood-vesset of the body; heuce through the vetus into the inferior cava, and by this Way tuto the right fide of the heart. Τhis appears to be the cause of thephenomenon of Whicli Malpighi speatis, Where he says that
tribute after birth to the circulation of the blood, and evectat of the purer blood, as alleged in n. 279. Here it is that weare preceded in sume degree by the light os experimental kΠOWledge; sor the capillaments of the vesseis that are penetraledWith a blood not red but White, are opened for the reception Ofthe red blood equalty by tho influx of the brains into the fibres, and by the expansion and contraction of the lungs. I say by the influx of the brains, as appears When the bratus are assected With gries, indignation, anger, shame, kc.; for then the red
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bl00d immodiutoly forces iis Way into the texture of the capillary Ve8Seis, and suffuses the cheolis and other extremities Withreduess and sire. A similar result is produced by the generalessori of the lungs, as in the case of Wresiling, fghting, StriVing, parturition, expelling the faeces, Ahouting, and a thousand
367. But be re We cari properly comparo the action Os thebratus With that of the lungs, and inser that the lungs as Woli asthe bratus promoto the circulation of this whito blood, it is of importance to demonstrate, that the action of the lungs isequialy universat With that of the bratus, and that Whateverpart of the body is devoid of this action, censes in a Shori timeto be associaled With the other paris. It would seem at 1irstsight, as is the effect os respiration did not extend far beyond thethorax; but is We contempla te the severat varieties of respiration, and reduce them to One common Or generat reSult, Weshali perceive, that is the respiration does not alWays actuallyoxtund beyond the thorax, stili it is in the essori to do so, Or to
368. Respiration may be either ordinary or extraordinary, orasthmatio and morbid, or disserent according to the disserent disposition as Weli as action Os the ribs, the vertebrae, the Sternum, the nech, the abdomen, the brain, the cerebellum, themedulla oblongata and spinalis, the nerves and the muSeles :respiration is One thing in Womeu WhO Wear tight Stays, anotherthing in pregnant Women; disserent again in insanis, boys, adulis, and old persons, reSpectively : respiration may be ei ther pectoral, attended With rising of the chest; or dorsat, With adduction and extrusion os the vertebrat column; Or subthoracicand abdominat: it is disserent again in Other States, sor inStance, While We are fleeping and 8noring, hom What it is While we areaWine, Standing upon the laet, bending sorWard 8, backWards,or SideWards, or lying upon the bach, or upon the breast: it Varies also respectively While We are laboring, Shouting, Speak