Page images
PDF
EPUB

it, but only in this dire&ion; yer does he himself, confess, that because these two Motions of the Earth, the Annual and Diurnal, would be much more conveniently inade upon parallel Axes, therefore, according to the Laws of Mechanisın, they should be perpetually brought nearer and nearer together, 'till at ļength the Equator and Ecliptick come to have their Axis parallel, which as it hath not yet come to pass, so neither hath there been for these last two Thousand Years (according to the best Observations and Judgments of Astronomers) any nearer approach made of them one to another. Wherefore the Continuation of these two. Motions of the Earth, the Annual and Diurnal, upon Axes not parallel, is refolvable into nothing but a final and mental Cause, or the cô Béansov, because it was best it should be so, the variety of the Seasons of the Year depending thereupon. But the greatest of all the particular Phanomena, is the Formation and Organization of the Bodies of Animals, confisting of such variety and curiosity, that these mechanick Philosophers being no way able to give an account thereof from the necessary Motion of Matter, urguided by Mind for Ends, prudently therefore break off their System there, when they should come to Animals, and so leave it altogether untouch’d. We acknowledge indeed there is a Pofthumous Piece extant, imputed to Cartes, and entituled, De la formation du Fætus, wherein there is some Pretence made to falve all this fortuitous Mechanisın. But as the Theory thereof is built wholly upon a false Suppo

sition,

lition, sufficiently confuted by our Harvey in his Book of Generation, that the Seed doth materially enter into the Composition of the Egg; fo is it all along precarious and exceptionable : Nor doth it extend at all to Differences that are in several Animals, nor offer the least reason why an Animal of one Species might not be formid out of the Seed of another. Thus far the Dr. with whom for tlie main I do consent. I shall only add, that Natural Philofophers, when they endeavour to give an account of any of the Works of Nature by preconceivd Principles of their own, are for the most part grofly inistaken and confuted by Experience ; as Des Cartes in a Matter that lay before him, obvious to Sense, and infinitely more easie to find out the Cause of, than to give an account of the Formation of the World ; that is the Pulse of the Heart, which he attributes to an Ebullition and sudden Expansion of the Blood in its Ventricles, after the manner of the Milk, which being heated to such a degree, doth fuddenly, and as it were all at once, flush up and run over the Vessel. Whether this Ebullition be caus’d by a Nitro-Sulphureous Ferment lodg’d especially in the left ventricle of the Heart, which mingling with the Blood, excites such an Ebullition, as we see inade by the mixture of fome Chymical Liquors, viz. Oil of Vitriol, and deliquated Sált of Tartar ; or by the vital Flame warming and boiling the Blood. But this Conceit of his is contrary both to Reafon and Experience : For, first, it is altogether

[merged small][ocr errors]
[ocr errors]

unreasonable to imagine and affirm that the cool venal Blood should be heated to so high a degree in so short a time as the Interval of two Pulses, which is less than the fixth part of a Minute Secondly, in cold Animals, as for example, Eels, the Heart will beat for many hours after it is taken out of the Body, yea, tho' the Ventricle be open'd, and all the Blood squeez'd oută Thirdly, The Process of the Fibres which compound the sides of the Ventricles running in Spiral Lines froin the Tip to the Base of the Heart, some one way, and some the contrary, do clearly shew that the Systole of the Heart is nothing but a Muscular constriction, as a Purse is shut by drawing the Strings contrary ways: Which is also confirm'd by experience ; for if the Vertex of the Heart be cut off, and a Finger thrust up into one of the Ventricles, in ea very Systole the Finger will be sensibly and manifestly pinch’d by the sides of the Ventricle. But for a full confutation of this Fancy, I refer the Reader to Dr. Lower's Treatise de Corde, Chap. 2. And Des Cartes's Rules concerning the transferring of Motion from one Body iii motion to another in motion or in rest, are the nost of them by Experience found to be false; as they affirm who have made Trial of thein.

This Pulfe of the Heart Dr. Cudrworth would have to be n10 Mechanical, but a Vital Motion, which to me seems probable, because it is not under the command of the Will; nor are we conscious of any Power to cause or to restrain it, but it is carried on and continued without our

knowledge

knowledge or notice; neither cár it be caused by the impulse of any external Movent, unless it be Heat. But how can the Spirit agitated by Heat, unguided by a vital Principle, produce such a regular reciprocalMotion? If that Site which the Heart and its Fibres have in the Diaftole be most natural to them, (as it seems to be) why doth it again contract it felf, and not rest in that pofture? If it be once contracted in a Systole by the influx of the Spirits, why, the Spirits continually flowing in without let, doth it not always renain fo ? [for the Systole seems to refemble the forcible bending of a Spring, and the Diaftole its flyingout again to its natural site.] What is the Spring and principal Efficient of this Reciprocation? What directs and moderates the Motions of the Spirits ? They being but stupid and senselefs inatter, cannot of themselves continue any regular and constant motioir, without the guidance and regulation of some intelligent Being. You will say, What Agent is it which you would have to effect this? The sensitive Soul it cannot be, because, that is indivisible, but the Heařt when feparated wholly from the Body in some Animals, continues still to pulse for a considerable time; nay when it hath quite ceas'd, it may be brought to beat a-rew by the Application of warm Spittle, or by pricking it ģently with a Pin or Needle. I answer, it may be in these Instances, the scattering Spirits remaining in the Heart, may for a time, being agitated by heat, cause these faint Pulsations; tho I should rather attribute them to a plastick

Nature

[ocr errors]

Nature or Vital Principle, as the Vegetation of Plants must also be.

But, to proceed, neither can I wholly acquiesce in the Hypothesis of that Honourable and deservedly Famous Author, I formerly had occa fion to mention, which I find in his free inquiry into the Vulgar Notion of Nature, p. 77, 78. de liver'd in these words. “ I think it probable, " that the great and wife Author of things did, " when he first form'd the Universe and undi

ftinguish'd Matter into the world, put its parts into various Motions, whereby they were necessarily divided into numberless Portions of differing Bulks, Figures and Situations, in respect of each other : And that by his infinite

Wisdom and Power he did so guide and over" rule the Motions of these Parts, at the begin“ ning of things, as that (whether in a shorter

or a longer time Reason cannot determine) “ they were finally dispos'd into that beautiful “ and orderly Frame that we call the World ;

amorig whose Parts some were so curiously « contrivd, as to be fit to becoine the Seeds or “ feminal Principles of Plants and Animalsı

And I further conceive, that he settled such “ Laws or Rules of local Motion among the

parts of the Universal Matter, that by his ordinary and preserving Concourse, the several parts of the Universe thus once compleated,

should be able to maintain the great Con= “ struction or System and Oeconomy of the " Mundane Bodies, and propagate the Species “ of living Creatures”. The fame Hypothefis he

repeats

« PreviousContinue »