5. I come now to confider the argument that may be drawn in favour of PHYSICS. the receiv'd notion of nature, from the critical evacuations, which happen in difeafes; and the ftrange ftratagems that nature is faid to make ufe of, The vulgar notion of a crifis to free herself from the noxious humours that opprefs her. This argument I willingly acknowledge to be very confiderable; for we really fee, that in continual fevers, efpecially in hot climates, there ufually happen, at certain times of the difeafe, notable commotions, or conflicts, after which the morbific matter is difpofed of, and difcharged by ways strange and furprizing; to the great and fudden relief of the patient. Upon this account, I take the argument drawn from crifes to be much the ftrongest that can be urged for the opinion from which I diffent. But the body of a man is an incomparable engine, which the moft wife author of things has fo skilfully framed, for lafting many years, that, if there were in it an intelligent principle of felf-prefervation, (as the naturifts suppose there is) things would not, in moft cafes, be better, or otherwife managed, for the prefervation of the animal, than they generally are." So that the question is not, whether there be a great deal of providence and wisdom exercifed in the crifes of difeafes; but upon what account it is, that these appofite things are perform'd? 'Tis the univerfal opinion of physicians, that 'tis the intelligent principle they call nature; which, being follicitous for the welfare of the patient, and diftreffed by the quantity or hurtfulness of the morbific matter, watches her opportunity to expel it haftily out of the body, by the most safe and convenient ways, which, in the prefent condition of the patient, can be taken. I, on the other side, attribute crifes to the wifdom and ordinary providence of God, exerting itself by the mechanism of that great machine, the world; and of that fmaller engine, the human body, as conftituted in the patient's circumftances. The reasons that hinder me from acquiefcing in the general opinion of phyficians, about crifes, are principally thefe. Crifes, properly fo call'd, very feldom happen, except in fevers, and the like acute difeafes; where, according to the common courfe of things, the diforder is foon terminated, either by recovery, death, or a change into fome other difeafe: but chronical fickneffes, unless they happen to be accompany'd with feverish diftempers, ufually have no crifes. This argues, that nature doth not make critical evacuations, upon account of fuch care and watchfulness, as phyficians afcribe them to fince the neglects to employ fo wholefome an expedient in difeafes, that are often no lefs dangerous and mortal than acute ones, whilft fhe attempts to cure by crifes. examin'd. Again, critical evacuations may be procured by the bare mechanism of the body; for, by virtue of that, the fibres, or motive organs of the ftomach, Vifcera, and other parts, being diftended, or vellicated, by the abundance, or acrimony, of the peccant matter, will, fometimes, by fuch an irritation, be made to contract themfelves vigorously, and to throw out the matter that offends the part, either by the emunctories of the body, or by whatever paffages it can, with most ease, be discharged. Thus, VOL. II. S when PHYSICS. to many motions, acknowledg'd to be natural; as the heat of the fun to the germination and flourishing of feveral plants, hung up in the air in the fpring. And if in the air-pump you place feveral infects, and withdraw the common air from the receiver, they will lie movelefs, as if they were dead, tho' it be for feveral hours, whilft they are kept from enjoying the air: but when that is permitted again to return upon them, they will prefently revive, and be brought to move again; as if a fly, for instance, refembled a little wind-mill, in being movelefs of itself, and requiring the action of the air to put its wings, and other parts into motion. But, fince motion is not effential to matter, as divifibility and impenetrability are believ'd to be; the motions of all bodies, at leaft at the beginning of things, and of most, the causes of whose motions we can difcern, were impreffed on them; either by an external immaterial agent, God, or by external portions of matter acting on them. And tho' motion be defervedly made a principal part of Aristotle's definition of nature; yet men ufually call fuch motions natural, as are very hard to distinguish from thofe they call violent. Thus, when water falls to the ground, they tell us, this motion is natural to that liquor, as 'tis a heavy body; but when a man fpurts water into the air, they pronounce the motion, because of its tendency upwards, to be contrary to nature: yet when he draws water into his mouth thro' a pipe held perpendicularly, they will have this motion, tho' directly upwards, to be not violent, but natural. So when a blown bladder, let fall upon a floor, rebounds, the descent and afcent are both faid to be natural motions; tho' the former tends towards the centre of the earth, and the latter from it. And fo, if, from a confiderable height, you let fall a sphere of fome close wood, not too heavy, into a deep veffel of water, it will defcend far in that liquor, by a natural motion; yet its contrary motion, upwards, ought not to be esteem'd violent, fince, according to the schools, being lighter in Specie than water, 'tis natural to it to affect its proper place; for which purpose, it must ascend to the top of the liquor, and float. 'Tis, however, from these tendencies to oppofite points, that men judge many motions of bodies to be natural, or violent. And, indeed, fince it must be indifferent to a lifelefs and infenfible body, to what place 'tis made to move, all its motions may, in one refpect, be faid to be natural; and, in another, violent: for as very many bodies, of a vifible bulk, are fet in motion by external impellents, upon which account, their motions may be faid to be violent; fo the generality of impell'd bodies, move upwards, downwards, &c. toward any part of the world, in what line foever they find their motion least refifted; which impulfe and tendency being given by virtue of what they call the general laws of nature, the motion may be faid to be natural. The vulgar diftinction of motion, therefore, into natural and violent, is not fo clear and well-grounded, as to oblige us to admit that there is such a Being as the naturifts affert. 5. I come now to confider the argument that may be drawn in favour of PHYSICS. the receiv'd notion of nature, from the critical evacuations, which happen in diseases; and the ftrange ftratagems that nature is faid to make ufe of, The vulgar notion of a crifis to free herself from the noxious humours that oppress her. This argument I willingly acknowledge to be very confiderable; for we really fee, that in continual fevers, especially in hot climates, there ufually happen, at certain times of the disease, notable commotions, or conflicts, after which the morbific matter is difpofed of, and difcharged by ways ftrange and furprizing; to the great and fudden relief of the patient. Upon this account, I take the argument drawn from crifes to be much the ftrongest that can be urged for the opinion from which I diffent. But the body of a man is an incomparable engine, which the moft wife author of things has fo skilfully framed, for lafting many years, that, if there were in it an intelligent principle of felf-prefervation, (as the naturifts suppose there is) things would not, in moft cafes, be better, or otherwife managed, for the prefervation of the animal, than they generally are. So that the question is not, whether there be a great deal of providence and wisdom exercised in the crifes of difeafes; but upon what account it is, that these appofite things are perform'd? 'Tis the univerfal opinion of phyficians, that 'tis the intelligent principle they call nature; which, being follicitous for the welfare of the patient, and diftreffed by the quantity or hurtfulness of the morbific matter, watches her opportunity to expel it haftily out of the body, by the most fafe and convenient ways, which, in the prefent condition of the patient, can be taken. I, on the other fide, attribute crifes to the wifdom and ordinary providence of God, exerting itself by the mechanifm of that great machine, the world; and of that fmaller engine, the human body, as conftituted in the patient's circumftances. The reasons that hinder me from acquiefcing in the general opinion of phyficians, about crifes, are principally these. Crifes, properly fo call'd, very feldom happen, except in fevers, and the like acute difeafes; where, according to the common courfe of things, the disorder is foon terminated, either by recovery, death, or a change into fome other difeafe: but chronical fickneffes, unless they happen to be accompany'd with feverish diftempers, ufually have no crifes. This argues, that nature doth not make critical evacuations, upon account of fuch care and watchfulness, as phyficians afcribe them to; fince fhe neglects to employ fo wholesome an expedient in diseases, that are often no lefs dangerous and mortal than acute ones, whilft fhe attempts to cure by crifes. Again, critical evacuations may be procured by the bare mechanism of the body; for, by virtue of that, the fibres, or motive organs of the ftomach, Vifcera, and other parts, being diftended, or vellicated, by the abundance, or acrimony, of the peccant matter, will, fometimes, by fuch an irritation, be made to contract themselves vigorously, and to throw out the matter that offends the part, either by the emunctories of the body, or by whatever paffages it can, with moft eafe, be discharged. Thus, VOL. II. S when examin'd. PHYSICS. when fome men find their stomachs burden'd with aliment, they provoke it to unload itself with a feather, or the like, without being beholden to nature's watchfulness for a crifis, which, probably, fhe would not attempt. And as 'tis ufual for crifes to be made in fevers by large hemorrhagies av the nose, and other parts; which is afcribed to nature's care for the patient's recovery; I muft add, that it hath been often obferved, that even, after death, large bleedings have happen'd at feveral other parts of the body; which fhews, that fuch excretions may be made by virtue of the ftructure of the machine, or the turgefcence and acrimony of the humours, without any defign of nature to fave the life of the patient. Indeed, if it appear'd, by experience, that all crifes of diseases either expell'd the morbific matter, or notably relieved the patient; the critical attempts of nature would much favour the opinion men have conceiv'd of her vigilance and conduct: but unwelcome inftances daily fhew, that, as fome crifes are falutary, fo others prove mortal. And, among thofe that do not directly kill the patient, there are feveral which leave him in a worse condition than he was before.. I therefore wonder not, that physicianshave thought themselves obliged to lay down feveral circumftances, as neceffary requifites of a laudable crifis; if any of which be wanting, 'tis not thought of the best kind: and if the contrary to fome of them happen, 'tis to be judged either pernicious, or hurtful. For as there are two general ways fuppofed to be employ'd by nature, in making crifes, the one by expulfion of the peccant matter out of the body; and the other, by the fettling of the matter fomewhere within it; neither of these is conftantly fuccefsful. Whence experience hath obliged physicians to divide crifes not only into perfect, that fully determine the event of the difeafe; and imperfect, that only alter it for the better or the worfe; but into falutary, that quite relieve the patient; and mortal, which deftroy him. And, to a perfect and falutary crifis, fome require no less than fix conditions; that it be preceded by figns of coction; that it be made by a manifeft and fufficient excretion, or tranflation; that it happen upon a critical day; that it leave no relicks behind, to endanger a relapfe; that it be without dangerous symptoms; and, laftly, fuitable to the nature of the disease, and the pa tient. Hence it may appear no common thing to meet with a perfect and falutary crifis, fince fo many laudable conditions muft concur in it. And, indeed, nature ufually takes up but with imperfect ones; and it were happy if she made no better, provided she made no worse. But 'tis found, by fad experience, that she rouzes herself up to make a crisis, not only upon improper days, but also when there appear no figns of coction; and, by these unfeasonable attempts, weakens the patient and increases the malady, or, perhaps, makes it speedily mortal. Nor will it justify nature, to fay, that these attempts are accidentally brought on, by the acrimony, or importunity of the morbific matter, by which fhe is provoked, before the time, to endeavour an expulfion of it. For if nature be fo prudent and watchful a guardian, as is thought, fhe fhould not fuffer herfelf to be PHYSICS. provoked to act prepofterously, and make furious attempts, that lavish the little strength the patient hath fo much need of. And, therefore, phyficians often do very well, when, agreeably to the dictates of prudence, they forget how much wifdom they are apt to afcribe to nature, and employ their beft skill and remedies to fupprefs, or moderate, the inordinate motions, or the improper and profufe evacuations, that fhe, when irritated, rafhly begins to make. And tho' the crifes that are made by a tranflation of the peccant matter, or by lodging it in fome particular part of the body, be often, when they are not falutary, fomewhat lefs hurtful than thofe made by excretion; yet thefe, frequently, prove dangerous; fometimes producing inward impofthumes, or external tumors, in parts either noble by their functions, fituation, connexion, or fympathy with others, that are not to be without hazard, or great inconvenience, opprefs'd. I know that physicians make it a great argument of nature's providence and skill, that the watches for the concoction of the peccant matter, before The attempts to expel it by a crifis. But what is to be meant by this coction of humours, they do not clearly declare. As I understand it, when they say, that a portion of peccant matter is brought to coction, they mean, that it has acquir'd fuch a difpofition, as makes it more fit than before, to be separated from the founder portion of the mafs of blood, or from the confiftent parts to which it, perhaps, formerly adhered; and to be afterwards expell'd out of the body. As where the lungs are affected by a fresh taken cold, we fee, that, after a few days, the phlegm is made more fluid, and that lodg'd in them, is easily brought up by the coughing, which could not diflodge it before. And, in fevers, that feparation in the urine, which phyficians look upon as a good fign of coction, feems to be produc'd by fome part of the peccant matter, that, beginning to be feparated from the blood, mixes with the urine, and is not ufually distinguish'd from it, whilft this liquor is warm; but when grown cold, on account of its weight, or texture, appears in a diftinct form; as of a cloud, fediment, &c. But, whatever they mean by coction, 'tis plain that, on many occafions, nature waits not for it, but unreasonably, and often with danger, attempts to throw off the matter that offends her, before it be duly prepar'd for expulfion... 'Tis a circumstance of crifes, thought the most wonderful, that nature often, by very unusual ways, and at unexpected places, difcharges the matter that offends her, and thereby either cures, or notably relieves the pa tient. But, fetting aside extraordinary cafes, it feems probable, that the performances of nature, in common crifes,are, in fome mea fure, referable to the particular condition of the matter to be expell'd, but principally to a peculiar difpofition in the primitive fabric of fome parts of the patient's body; or fome unufual change made in the conftruction of these parts by the disease itself, or |