as I have sometimes taken great Pleasure to Look upon. Sometimes the Bodies mingled by the Fire are Differing enough as to Fixidity and Volatility, and yet are so combin’d by the first Operation of the Fire, that it self does scarce afterwards Separate them, but only Pulverize them; whereof an Instance is afforded us by the Common Preparation of Mercurius Dulcis, where the Saline Particles of the Vitriol, Sea Salt, and sometimes Nitre, Employ’d to make the Sublimate, do so unite themselves with the Mercurial Particles made use of, first to Make Sublimate, and then to Dulcifie it, that the Saline and Metalline Parts arise together in many successive Sublimations, as if they all made but one Body. And sometimes too the Fire does not only not Sever the Differing Elements of a Body, but Combine them so firmly, that Nature her self does very seldom, if ever, make Unions less Dissoluble. For the Fire meeting with some Bodies exceedingly and almost equally Fixt, instead of making a Separation, makes an Union so strict, that it self, alone, is unable to Dissolve it; As we see, when an Alca-
