Experimental notes of the mechanical origine or production of fixtness.

CHAP. IX. (Book 9)

NOtwithstanding all that I have been obliged to say to the Dis∣advantage of the Chymical Princi∣ples, in reference to the Explication of Qualities, I would not be thought to grant, that the Peripateticks have reason to triumph, as if their four Ele∣ments afforded a better Theory of Qualities. For, if I had, together with leisure enough to perform such a Task, any obligation to undertake it, I presume, it would not be difficult to shew, that the Aristotelian Doctrine about particular Qualities is liable to some of the same Objections with the Chymical, and to some others no less considerable; and that, to derive all the Phaenomena their Doctrine ought to solve from Substantial Forms and real Qualities Elementary, is to impose on us a Theory more barren and pre∣carious than that of the Spagy∣rists.

That to derive the particular Qua∣lities of bodies from those Substantial Forms, whence the Schools would have them to flow, is but an insuffici∣ent and unfit way of accounting for them, may appear by this, that Substan∣tial Forms themselves are things, whose existence many Learned Phi∣losophers deny, whose Theory many of them think Incomprehensible, and the most Candid and Judicious of the Peripateticks themselves confess it to be very abstruse; so that from such doubtful and obscure Principles we can hardly expect clear Explications of the nature and Phaenomena of Qua∣lities; not to urge, that the Aristoteli∣an Definitions, both of Qualities in general, and of divers of the more fa∣miliar Qualities in particular, as Heat, Cold, Moisture, Diaphaneity, &c. are far enough from being clear and well framed, as we elsewhere have occasi∣on to shew.

Another thing, which makes the Scholastic Doctrine of Qualities un∣satisfactory, is, that it seldom so much

as attempts to teach the Manner how the Qualities themselves and their Effects or Operations are produced. Of this you may elsewhere find an Instance given in the Quality that is wont to be first in the list, viz that of Heat, which though it may intelligi∣bly and probably be explicated by the Corpuscular Hypothesis, yet in the Peripatetic account that is given of it, is both too questionable and too su∣perficial to give much Content to a Rational Inquirer. And indeed to say, that a Substantial Form (as that of the Fire) acts by a Quality (call'd Heat) whose Nature 'tis to produce such an effect (as to soften Wax or harden Clay) seems to be no other in sub∣stance, than to say, that it produces such an effect by some power it has to produce it. But what that power is, and how it operates, is that, which, though we most desire to know, we are left to seek. But to prosecute the Imperfections of the Peripatetick Hy∣pothesis, were to intrench upon ano∣ther discourse, where they are more

fully laid open. And therefore I shall now but lightly glance upon a couple of imperfections, that more particularly relate to the Doctrine of Qualities.

And first I do not think it a Con∣vincing Argument that is wont to be imployed by the Aristotelians for their Elements, as well as by the Chymists for their Principles, that, be∣cause this or that Quality, which they ascribe to an Element or a Principle, is found in this or that body, which they call mixt, therefore it must owe that Quality to the participation of that Principle or Element. For, the same Texture of parts or other mo∣dification of matter may produce the like Quality in the more simple and the more compounded body, and they may both separately derive it from the same Cause, and not one from the Participation of the other. So Water and Earth and Metals and Stones, &c. are heavy upon the ac∣count of the common Cause of Gra∣vity, and not because the rest partake

of the Earth; as may appear in Ele∣mentary water, which is as simple a body as it, and yet is heavy: So wa∣ter and oil, and exactly deflegm'd Spi∣rit of Wine, and Mercury, and also Metals and Glass of Antimony, and Minium or calcin'd Lead, whilest these three are in fusion are fluid, being made so by the variously determined motions of their minute parts and o∣ther Causes of Fluidity, and not by the participation of water, since the arid Calces of Lead and Antimony are not like to have retained in the fire so volatile a liquor as water, and since Fluidity is a Quality that Mer∣cury enjoys in a more durable man∣ner than Water it self: For that me∣talline liquor, as also Spirit of Wine well Rectified, will not be brought to freeze with the highest degree of Cold of our sharpest winters, though a far less degree of Cold would make water cease to be fluid and turn it into Ice.

To this I shall only add (in the se∣cond place,) that 'tis not unpleasant

to see, how arbitrarily the Peripate∣ticks derive the Qualities of bodies from their four Elements, as if, to give an instance in the lately named Qua∣lity, Liquidity, you shew them exact∣ly deflegmed Spirit of Wine, and ask them, whence it has its great Fluid∣ness, they will tell you from water, which yet is far less fluid than it, and this spirit of wine it self is much less so than the flame into which the spi∣rit of wine is easily resoluble. But if you ask, whence it becomes totally inflammable, they must tell you, from the fire; and yet the whole body, at least as far as sense can discover, is fluid, and the whole body becomes flame, (and then is most fluid of all;) so that fire and water as contrary as they make them, must both be by vast odds predominant in the same body. This spirit of wine also, being a li∣quor whose least parts that are sen∣sible are actually heavy, and compose a Liquor which is seven or eight hun∣dred times as heavy as Air of the same bulk, which yet experience

shews not to be devoid of weight, must be supposed to abound with Earthy particles, and yet this spiri∣tuous liquor may in a trice become Flame, which they would have to be the lightest body in the world.

But, to enlarge on this subject, would be to forget, that the design of this Tract engages me to deal not with the Peripatetic School, but the Spagyrical. To which I shall there∣fore return, and give you this ad∣vertisement about it, that what I have hitherto objected is meant a∣gainst the more common and receiv∣ed Doctrine about the Material Prin∣ciples of bodies reputed mixt, as 'tis wont by vulgar Chymists to be ap∣plied to the rendring an account of the Qualities of substances Corpo∣real; and therefore I pretend not, that the past objections should con∣clude against other Chymical Theo∣ries than that which I was concern∣ed to question. And if adept Philo∣sophers, (supposing there be such) or

any other more than ordinarily Intel∣ligent Spagyrists, shall propose any particular Hypotheses, differing from those that I have questioned, as their Doctrine and Reasons are not yet known to me; so I pretend not that the past Arguments should conclude against them, and am willing to think, that Persons advantaged with such peculiar opportunities to dive into the Mysteries of Nature, will be able to give us, if they shall please, a far better account of the Qualities of bodies than what is wont to be pro∣posed by the generality of Chy∣mists.

Thus, dear Pyrophilus, I have laid before you some of the chief Imper∣fections I have observed in the vul∣gar Chymists Doctrine of Qualities, and consequently I have given you some of the chief Reasons that hin∣der me from acquiescing in it. And as my objections are not taken from the Scholastical subtleties nor the doubtful speculations of the Peripa∣teticks or other Adversaries of the

Hermetick Philosophy, but from the nature of things and from Chymical experiments themselves; so I hope, if any of your Spagyrical friends have a minde to convince me, he will at∣tempt to doe it by the most proper way, which is, by actually giving us clear and particular explications, at least of the grand Phaenomena of Qua∣lities; which, if he shall do, he will find me very ready to acquiesce in a Truth that comes usher'd in, and endear'd by so acceptable and useful a thing, as a Philosophical Theory of Qualities.