Disjoyn those of a Differing Nature. To this I answer, That this Effect is far from being so Essential to Heat, as 'tis Generally Imagin'd; for it rather Seems, that the True and Genuine Property of Heat is, to set a Moving, and thereby to Dissociate the parts of Bodies, and Subdivide them into Minute Particles, without regard to their being Homogeneous or Heterogeneous, as is apparent in the Boyling of Water, the Distillation of Quicksilver, or the Exposing of Bodies to the action of the Fire, whose Parts either Are not (at least in that Degree of Heat Appear not) Dissimilar, where all that the Fire can do, is to Divide the Body into very Minute Parts which are of the same Nature with one another, and with their _Totum_, as their Reduction by Condensation Evinces. And even when the Fire seems most so _Congregare Homogenea, & Segregare Heterogenea_, it Produces that Effect but by Accident; For the Fire does but Dissolve the Cement, or rather Shatter the Frame, or [tructure [Errata: structure] that kept the Heterogeneous Parts of Bodies together, under one Common Form; upon which Dissolution the Component Particles of the Mixt, being Freed and set at Liberty, do Naturally, and oftentimes without any Operation of the Fire, Associate themselves each with its Like, or rather do take those places which their Several Degrees of Gravity and Levity, Fixedness or Volatility (either Natural, or Adventitious from the Impression of the Fire) Assigne them. Thus in the Distillation (for Instance) of Man's Blood, the Fire do's First begin to Dissolve the _Nexus_ or Cement of the Body; and then the Water, being the most Volatile, and Easy to be Extracted, is either by the Igneous Atomes, or the Agitation they are put into by the Fire, first carried up, till Forsaken by what carried it up, its Weight sinks it down into the Receiver: but all this while the other Principles of the Concrete Remain Unsever'd, and Require a stronger Degree of Heat to make a Separation of its more Fixt Elements; and therefore the Fire must be Increas'd which Carries over the Volatile Salt and the Spirit, they being, though Beleev'd to be Differing Principles, and though Really of Different Consistency, yet of an almost Equal Volatility. After them, as less Fugitive, comes over the Oyl, and leaves behinde the Earth and the _Alcali_, which being of an Equal Fixednesse, the Fire Severs them not, for all the Definition of the Schools. And if into a Red-hot Earthen or Iron Retort you cast the Matter to be Distill'd, You may Observe, as I have often done, that the Predominant Fire will Carry up all the Volatile Elements Confusedly in one Fume, which will afterwards take their Places in the Receiver, either according to the Degree of their Gravity, or according to the Exigency of their respective Textures; the Salt Adhering, for the most part, to the Sides and Top, and the Phlegme Fastening it self there too in great Drops, the Oyle and Spirit placing themselves Under, or Above one