And first, as for the very way of Probation, which the more Learned and more Sober Champions of the Chymical cause employ to evince the Chymical Principles in Mixt Bodies, it seems to me to be farr enough from being convincing. This grand and leading Argument, your _Sennertus_ Himself, who layes Great weight upon it, and tells us, that the most Learned Philosophers employ this way of Reasoning to prove the most important things, proposes thus: _Ubicunque_ (sayes he) _pluribus eaedem affectiones & qualitates insunt, per commune quoddam Principium insint necesse est, sicut omnia sunt Gravia propter terram, calida propter Ignem. At Colores, Odores, Sapores, esse_ [Greek: phlogiston] _& similia alia, mineralibus, Metallis, Gemmis, Lapidibus, Plantis, Animalibus insunt. Ergo per commune aliquod principium, & subiectum, insunt. At tale principium non sunt Elementa. Nullam enim habent ad tales qualitates producendas potentiam. Ergo alia principia, unde fluant, inquirenda sunt._ In the Recital of this Argument, (sayes _Carneades_) I therefore thought fit to retain the Language wherein the Author proposes it, that I might also retain the propriety of some Latine Termes, to which I do not readily remember any that fully answer in English. But as for the Argumentation it self, 'tis built upon a precarious supposition, that seems to me neither Demonstrable nor true; for, how does it appear, that where the same Quality is to be met with in many Bodies, it must belong to them upon the Account of some one Body whereof they all partake? (For that the Major of our Authors Argument is to be Understood of the Material Ingredients of bodies, appears by the Instances of Earth and Fire he annexes to explain it.) 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. For if it be demanded how it comes to be Fluid, they will answer, that it participates much of the Nature of Water. And indeed, according to them, Water may be the Predominant Element in it, since we see, that several Bodies which by Distillation afford Liquors that weigh more then their _Caput Mortuum_ do not yet consist of Liquor enough to be Fluid. Yet if it be demanded how Quicksilver comes to be so heavy, then 'tis reply'd, that 'tis by reason of the Earth that abounds in it; but since, according to them, it must consist also of air, and partly of Fire, which they affirm to be light Elements, how comes it that it should be so much heavier then Earth of