Mikrokosmographia a description of the body of man. Together vvith the controuersies thereto belonging. Collected and translated out of all the best authors of anatomy, especially out of Gasper Bauhinus and Andreas Laurentius. By Helkiah Crooke Doctor of Physicke, physitian to His Maiestie, and his Highnesse professor in anatomy and chyrurgerie. Published by the Kings Maiesties especiall direction and warrant according to the first integrity, as it was originally written by the author.

QVEST. IX Whether the braine be moued by a proper & In-bred faculty; or by the motion of the Arteries.

IT is a very hard and difficult question whether the brain be moued by a proper and ingenit power of his owne, or by some outward violence. That the braine is moued no man in his right wits will deny vnlesse he bee vtterly ignorant of Anatomy. For in great wounds of the head wherein the Scull is broken and the membranes are detected, there is a manifest motion to be seene. Againe, in children new borne the forepart which we call the mould of the head doth so conspicuously pant * 1.1 and beat, that the very bones of the Scull which at that time be exceeding soft are moued therewith.

But because among the Philosophers there is a threefold kinde of motion, the first naturall, the second Animall, and the third violent. It is a great question to which of these kindes the motion of the braine is to be referred. It seemeth to some that the braine cannot be the originall of the Animall motion vnlesse it selfe be moued voluntarily; for it were absurd to say that there yssued from the braine into the whole body a power or fa∣culty which doth not reside therein as in the fountaine and originall.

But this opinion hauing no strength of argument to support it, hath also beene little ventilated by the Phisitions. For an Animall motion is proaireticall, or with choice being intended, remitted or intermitted according to the arbitriment of our will. Now wee know that the braine is not moued at our dispose, but according to it owne instinct, and therefore the motion thereof is not voluntary.

No man will say that it is violent; for Aristotle in his second book De ortu, opposeth * 1.2 that which is violent to that which is according to nature. It remaineth therefore that it is naturall By naturall I vnderstand not that which is only directed by Nature, but whatsoe∣uer

is not voluntary although it be gouerned by the soule.

Now whether this motion be of the whole braine or onely of the parts, and whether it be moued by an in-bred faculty or a power from without, that is, from the Arteries and the spirits it is greatly contrauerted. Galen in the second chapter of his fourth booke de differentijs pulsuum faith, that some thinke that the membranes onely do beate, others on∣ly the body of the braine, others both the membranes and the braine it selfe. Some are of opinion that the Animall spirits onely are moued not the bodye of the braine, which * 1.3 they illustrate by the example of a Vertigo or giddinesse wherein all things seeme to runne round, because of an inordinate and Turbulent motion of the spirits. The vulgar opini∣on is that the braine is not moued by any proper motion of it owne, but by a motion from * 1.4 without, that is to say, from the Arteries. Neither do his ventricles breathe in aer, (as Galen would haue it) neyther are they distended and contracted.

The reasons of this are: first it doth no more become a principle of motion to bee mooued, then it becommeth a principle of sense it selfe to haue sense, because as Aristotle saith, euery 〈 in non-Latin alphabet 〉〈 in non-Latin alphabet 〉 must be 〈 in non-Latin alphabet 〉〈 in non-Latin alphabet 〉 that is, euery instrumēt of sense must be destitute or void of al the obiects of that sense whereof it is an instrument: now the body of the braine hath not sense and therefore it hath no motion.

Furthermore, if the braine doe breath by a proper power, it would follow that because the substance thereof is soft, and the membrane that compasseth the ventricles very fine & thinne, it followeth I say, that that membrane must in the dilatation & contraction be vio∣lently torne asunder.

Thirdly, the third and fourth ventricles of the brain commonly so called, are of the same substance and temper that the vpper ventricles are of; for the vse of them all is one and the same; but it is granted that the latter ventricles doe not Respire, and therefore neyther shall the former be dilated or contracted.

They vrge further and thinke that this weapon hath a further edge. In grieuous wounds of the head when the braine is vncouered, the motion of the braine and the arteries doeth not appeare to differ at all, but as one Pulse is answerable to another, so likewise the mo∣tion of the braine and the arteries doe accord. Now if the braine did beat by an in-bred power, then must it needes be that some time the braine and the arteries should not beat a∣like and at the same instant.

Finally, there is no Attraction, no Expulsion without the helpe of fibres: so the heart hath his fibres, as also the stomacke, the guttes, the veines and the arteries; but in the brain there appeare no fibres at all; Ergo the Motion of the Diastole and Systole of the braine is not proper and peculiar vnto his substance.

Verily these reasons are so strong that the time hath bin (saith Laurē. whē I was cōuinced by them & constrayned to subscribe vnto this opinion; but looking ouer with a little more diligence the works of Galen and considering some passages in his Booke de Odoratus Or∣gano, de vsupartium, de Placitis Hippoc. & Platonis with better deliberation, at length I alte∣red my minde, and am now resolued that the body of the braine doeth respire by a proper faculty and in-bred Motion.

Let vs here Galen disputing in expresse words in the last Chapter of his Book de Odoratus Organo, Nature sayeth he hath not denyed motion to the braine whereby it might draw Ayre for * 1.5 his refrigeration and returne the same backe againe for the expurgation of superfluityes. Againe in the 4. Chapter of the same Booke, It is not impossible that the brayne should yeeld vnto it selfe a kinde of Motion (though it be but small) sometimes into it selfe sometimes out of it selfe, * 1.6 so that it should be lesse when it contracteth it selfe, and more spred when the parts of it are dila∣ted. Thus farre Galen.

But it shall behooue vs to establish his authority by reason also and waight of argu∣ment. * 1.7 It is most certaine that the Animall spirit is generated first in the vpper ventricles of the braine, which spirit being of it owne Nature ayrie and hot, stoode neede of the In∣spiration of ayre which was familiar and of kin vnto it, as well for his nourishment as that by it it might be refrigerated: wherefore when we draw our breath inward, the ayre also is drawne into the braine, and when we breath outward a fumid or smoaky vapour which is the excrement of the Animall spirit is thrust out and auoyded.

This Hippocrates elegantly expressed in his Booke de morbo sacro or of the Falling sick∣nesse. When (sayth he) a man drawes in ayre by his mouth & his nose is shut, first of all the breath * 1.8 commeth to the Brayne. Nowe this Inspiration of the ayre into the vpper ventricles of the

braine and the Expiration of the same is not made by arteries, but by certaine protuberati∣ons or swelling productions of the braine much like the Nipples of a womans Pap, which also are the Organs of smelling. The Motion therefore of the braine which is accompli∣shed by Inspiration and Expiration proceedeth from the braine it selfe not from the arte∣ries. Againe, that the ayre is drawne in by these productions may thus be proued.

The ayre and odours doe passe by one and the same way, for no smell can be felt al∣though it be driuen violently into the nose vnlesse therewith ayre be drawne in: now odors do passe into the braine by those productions before named, not by Arteries: and there∣fore by the same productions ayre is inspirated and transported into the foreward ventri∣cles.

Furthermore, if the braine do beate by the Arteries and not by anin-bred power for * 1.9 the generation of spirits; why then is not the spinall marrow also moued? You will say haply, that in the marrow of the backe there is not so great plenty of Arteries as are found in the braine it selfe. I answere, it may well be, for there is not the same quantity of mat∣ter or substance in the braine and the marrow. But if you compare both bodies together, then will the proportion of the Arteries be as great which runne through the membranes inuesting the marrow. Wherefore the spinall marrow is not therefore immoueable be∣cause it wanteth arteries, but because in it there is no generation of vitall spirits as there is in the Braine.

The third argument is on this manner. There is a certaine distance betwixt the body * 1.10 of the braine and the Dura meninx; not to giue way to the Systole and Dyastole of the Arte∣ries for they are not so lifted vp; nor to auoid danger because the Pia mater or thin mem∣brane is interposed betweene them: the distance therefore is left for the motion of the braine, and so we see that in the heart there is a distance betwixt it and the pericardium, least if they had touched one another they might haue beene interrupted.

Fourthly, how is it possible that so great a waight and masse of moysture as the braine is, should be dilated by a few small arteries? (for so I worthily call them that are sprinckled * 1.11 through the body of the Braine) seeing hat the large and notable Arteries of the spleene are not able to moue his rare and smal body? I answere, Anatomy teacheth vs that this bowel is wouen with infinite Arteries, and yet no man euer saide that the spleene was mo∣ued vnlesseit be in a tumor or inflamation, and then any part will be moued.

Fiftly, if the motion of the braine bee the motion of the Arteries and not of the mar∣rowy substance, then it was ridiculou•• to say that the braine is moued because the Arteries * 1.12 are onely moued. For so we might say that the stomack, the guts and the spleene were mooued because the Arteries do beate euery where. And therefore if wee imagine that the marrow of the braine is distended by the Dyastole of the Arteries, why should we not beleeue also that all the rest of the parts of the body do beate, because they haue all pro∣portionably as many Arteries?

Finally, the processe called vermi-formis, the Conarion and the buttocks of the braine do shew that there is a peculiar motion of the braine which differeth from the motion of * 1.13 the Arteries. For the wormy processe being made shorter, openeth the way which is from the third vnto the fourth ventricle, and whilst the same processe is extended it shut∣teth the passage againe least the spirit should returne into the vpper ventricles: so that it seemeth there is the same vse thereof that there is of the values placed at the mouth of the great Artery: now the opening and shutting of this clift proceedeth not from the Arte∣ries, but from an in bred power of the braine it selfe. It is therefore more probable to * 1.14 thinke with Galen that the braine is moued by a naturall motion and that proper to it selfe for the nutrition of Animall spirits, the tempering of them and their expurgation.

The reason and nature of this motion is on this manner. When the braine enlargeth it selfe it draweth ayre out of the nostrils by the mammillary processes and spirits out of the * 1.15 Textures or complications of the small Arteries. This ayre and these spirits it mingleth in that rest or interim which is between the two motions: but when in the Systole it con∣tracteth it selfe the sides falling together, the inward ventricles are straightned and the Animall spirits powred out of the foremost into the hinder ventricles.

But heere ariseth a scruple of no little moment, which is, whether the ayre is deriued to the braine when it is distended or when it is contracted? It should seeme that the ayre is * 1.16 drawn in in the constriction, because when the brain is contracted it departeth a little from the Scull: the Scul because it is immoueable doth not follow the contraction of the brain.

It is therefore necessary that there must bee a vacuitie betweene the Braine and the Scull, or else there must be aire drawne in, wherewith that place must be filled.

But wee thinke that the aire is drawne in in the dilatation of the braine, neither doe we allow that there is any emptie place left in the contraction, because in the contraction * 1.17 there is an expression of aire and fumed vapours through the sutures. Now let vs giue answer to that which is obiected against this our opinion.

They obiected first. That the braine is the beginning of motion, and therefore ought not to be moued. We answer, That indeed it must not be moued with the same Motion * 1.18 wherewith it moueth the parts: It giueth to the parts of the body voluntary Motion, but it selfe is moued with a naturall Motion. The braine is moued after the same manner that it hath sense: Now the sense of it is naturall as is the sense of bones or the bowels, whereby it being prouoked, auoydeth that which is offensiue vnto it, as we may see in sneezing and in the falling sickenesse. It is moued for the generation of animall spirits.

Their second argument was, that the ventricles of the braine did not respire, because * 1.19 in that perpetuall distension the thin Membrane of the Braine would haue beene broken: But they do not remember that in sneezing and in the Epilepsie, the contraction of the Braine is more violent then in the ordinary Motion; & yet in neither of those is the Mem∣brane broken. In Sternutation or sneezing, the Braine collecteth it selfe and is con∣tracted the better to exclude that which is offensiue vnto it. For the same that the cough is in the chest, and the hickocke in the stomach, the same is sneezing in the Braine. In the E∣pilepsie the whole Braine is contracted and corrugated.

Thirdly, they obtrude vnto vs: that the backeward ventricles do not respire, and therfore * 1.20 that the forward ventricles doe not dilate or contract themselues. I answer, first that I know not by what slight or art they can perceiue that the backeward ventricles doe not mooue. But let vs grant that they doe not, yet is their consequence not good; for the formost ventricles doe stand in neede of more, at least of more conspicuous Motion then the o∣ther, because in the formost the spirit is prepared and purged, in the backeward they are contained when they are pure, sincere and alreadie purged.

Fourthly, the motion of the braine and the arteries doth not appeare to bee vnlike * 1.21 the one vnto the other. I answer, that they are not indeede vnlike, because their vse is the same, there is the same finall cause of the generation of the spirits & of their expurgation.

Fiftly, they doe not thinke it as moued with any proper motion, because there ap∣peare in the braine no fibres at all. Wee answer, that the bones doe draw their nourish∣ment, * 1.22 and expell that which is superfluous without the helpe of Fibres. Lastly, there is not the same reason or nature of the heart and of the Braine: for the Heart stood neede of * 1.23 Fibres not for the traction and expulsion of aire but of blood. In the Dyastole the Heart draweth blood by the right Fibres, and the same blood it expelleth in the Systole by the transuerse. But the Braine when it is mooued draweth onely aire with most thinne vitall spirits, for the traction whereof there is no neede of the helpe of Fibres. Hence we thinke it is sufficiently manifest, that the Braine is moued by an in bred facultie, and not onely by the motion of the arteries.

Notes

• * 1.1

  That the braine is mo∣ued voluntari¦ly.
• * 1.2

  Disproued. That it is not violent.
• * 1.3

  The first opi∣nion.
• * 1.4

  That the braine is mo∣ued according to the motion of the arteries Reason 1.
• * 1.5

  That the braine doth respire by it owne force.
• * 1.6

  The 〈…〉〈…〉 Galne.
• * 1.7

  Reason. 1.
• * 1.8

  Hippocrates.
• * 1.9

  Reason 2.
• * 1.10

  Reason 3.
• * 1.11

  Reason 4.
• * 1.12

  Reason 5.
• * 1.13

  Reason 6.
• * 1.14

  The Conclu∣sion.
• * 1.15

  The reason of he motion of the braine.
• * 1.16

  A great que∣stion.
• * 1.17

  What wee thinke.
• * 1.18

  The reason of the contrary opinions are answered To the first.
• * 1.19

  To the se∣cond.
• * 1.20

  To the third.
• * 1.21

  To the fourth
• * 1.22

  To the fifth.
• * 1.23

  To the last.