Robert Boyle

“ For to begin with that very Example which he is pleas’d to alledge for himself; how can he prove, that the Gravity of all Bodies proceeds from what they participate of the Element of Earth? Since we see, that not only common Water, but the more pure Distill’d Rain Water is heavy; and Quicksilver is much heavier than Earth it self; though none of my Adversaries has yet prov’d, that it contains any of that Element. And I the Rather make use of this Example of Quicksilver, because I see not how the Assertors of the Elements will give any better Account of it then the Chymists. ”

“ And I shall proceed to consider the testimony of Experience, when I shall have first advertis'd You, that if Men were as perfectly rational as 'tis to be wish'd they were, this sensible way of Probation would be as needless as 'tis wont to be imperfect. For it is much more high and Philosophical to discover things a priore, then a posteriore. And therefore the Peripateticks have not been very sollicitous to gather Experiments to prove their Doctrine, contenting themselves with a few only, to satisfie those that are not capable of a Nobler Conviction. ”

“ I need not tell you what Complaints the more Candid and Judicious of the Chymists themselves are wont to make of those Boasters that confidently pretend, that they have extracted the Salt or Sulphur of Quicksilver, when they have disguis’d it by Additaments, wherewith it re58sembles the Concretes whose Names are given it ; whereas by a skilful and rigid Examen, it may be easily enough stript of its Disguises, and made to appear again in the pristine form of running Mercury. ”

“ And if some reasons did not forbid me, I could now tell you of a Menstruum I make my self, that doth more odly dissociate the parts of Minerals very fixt in the fire. So that it seems not incredible, that there may be some Agent or way of Operation found, whereby this or that Concrete, if not all Firme Bodies, may be resolv’d into parts so very minute and so unapt to stick close to one another, that none of them may be fixt enough to stay behind in a strong Fire, and to be incapable of Distillation; nor consequently to be look’d upon as Earth. ”

“ I will allow then, that the Chymists do not causelessly accuse the Doctrine of the four elements of incompetency to explain the Properties of Compound bodies. And for this Rejection of a Vulgar Error, they ought not to be deny’d what praise men may deserve for exploding a Doctrine whose Imperfections are so conspicuous, that men needed but not to shut their Eyes, to discover them. ”

“ Contemperation of the Light with shades, to observe, how that sometimes the number of Particles, of the same Colour, receiv'd into the Pores of a Liquor, or swiming up and down in it, do seem much to vary the Colour of it. I could here present you with particular instances to show, how in many (if not most) consistent Bodyes, if the Colour be not a Light one, as White, Yellow, or the like, the closeness of parts in the Pigments makes it look Blackish, though when it is display'd and laid on thinly, it will perhaps appear to be either Blew, or Green, or Red. ”

“ For what can a naked Fire do to Analyze a mixt Bodie, if its component Principles be so minute, and so strictly united, that the Corpuscles of it need less heat to carry them up, than is requisite to divide them into their Principles. So that of some Bodies the Fire cannot in close Vessels make any Analysis at all, and others will in the open Air fly away in the Forms of Flowers or Liquors, before the Heat can prove able to divide them into their Principles. ”

“ Nay nor perhaps all Vegetables, which may appear by what we said above of Camphire, Benzoin, &c. are resoluble by Fire into just such differing Schemes of Matter. Nor will the Experiments formerly alledg’d permit us to look upon these separated Substances as Elementary, or uncompounded. Neither will it be a sufficient Argument of their being Bodies that deserve the Names which Chymists are pleas’d to give them, that they have an Analogy in point of Consistence, or either Volatility or Fixtness, or else some other obvious Quality, with the suppos’d Principles, whose names are ascrib’d to them. ”

“ Indeed when I considered that the Tenents concerning the Elements are as considerable amongst the Doctrines of natural Philosophy as the Elements themselves are among the bodies of the Universe, I expected to find those Opinions solidly establish'd upon which so many others are superstructed. ”

“ But whatever (sayes Carneades) these Men may promise themselves from a Canting way of delivering the Principles of Nature, they will find the Major part of Knowing Men so vain, as when they understand not what they read, to conclude, that it is rather the Writers fault then their own. And those that are so ambitious to be admir’d by the Vulgar, that rather then go without the Admiration of the Ignorant they will expose themselves to the contempt of the Learned, those shall, by my consent, freely enjoy their Option. ”

“ Liquor than the Infusion of Lignum Nephriticum, it may yet be easily substituted in its Room, when we have a mind to examine, whether or no the Salt predominant in a Liquor or other Body, wherein 'tis Loose and Abundant, belong to the Tribe of Acid Salts or not. For if such a Body turn the Syrrup of a Red or Reddish Purple Colour, it does for the most part argue the Body (especially if it be a distill'd Liquor) to abound with Acid Salt. But if the Syrrup be made Green, that argues the Predominant Salt to be of a Nature repugnant to that of the Tribe of Acids. ”