Nor does the Proposition peremptorily Deny but that some Things Obtain'd by the Fire from a Mixt Body, may have been more then barely Materially pre-existent in it, since there are Concretes, which before they be Expos'd to the Fire afford us several Documents of their abounding, some with Salt, and Others with Sulphur. For it will serve the present Turn, if it appear that diverse things Obtain'd from a Mixt Body expos'd to the Fire, were not its Ingredients Before: for if this be made to appear it, will [Errata: appear, it will] be Rationall enough to suspect that Chymists may Decieve themselves, and Others, in concluding Resolutely and Universally, those Substances to be the Elementary Ingredients of Bodies barely separated by the Fire, of which it yet may be Doubted Whether there be such or No; at least till some other Argument then that drawn from the _Analysis_ be Brought to resolve the Doubt. That then which I Mean by the Proposition I am Explaining, is, That it may without Absurdity be Doubted whether or no the Differing Substances Obtainable from a Concrete Dissipated by the Fire were so Exsistent in it in that Forme (at least as to their minute Parts) wherein we find them when the _Analysis_ is over, that the Fire did only Dis-joyne and Extricate the Corpuscles of one Principle from those of the other wherewith before they were Blended. Having thus Explain'd my Proposition, I shall endeavour to do two things, to prove it; The first of which is to shew that such Substances as Chymists call Principles May be produc'd _De novo_ (as they speak.) And the other is to make it probable that by the Fire we may Actually obtain from some Mixt Bodies such Substances as were not in the Newly Expounded sence, pre-existent in them.