_Carneades_ having in Vain represented that their leasure could be but very short, that he had already prated very long, that he was unprepared to maintain so great and so invidious a Paradox, was at length prevail'd with to tell his Friend; Since, _Eleutherius_, you will have me Discourse _Ex Tempore_ of the Paradox you mention, I am content, (though more perhaps to express my Obedience, then my Opinion) to tell you that (supposing the Truth of _Helmonts_ and _Paracelsus's_ Alkahestical Experiments, if I may so call them) though it may seem extravagant, yet it is not absurd to doubt, whether, for ought has been prov'd, there be a necessity to admit any Elements, or Hypostatical Principles, at all. And, as formerly, so now, to avoid the needless trouble of Disputing severally with the _Aristotelians_ and the Chymists, I will address my self to oppose them I have last nam'd, Because their Doctrine about the Elements is more applauded by the Moderns, as pretending highly to be grounded upon Experience. And, to deal not only fairly but favourably with them, I will allow them to take in Earth and Water to their other Principles. Which I consent to, the rather that my Discourse may the better reach the Tenents of the Peripateticks; who cannot plead for any so probably as for those two Elements; that of fire above the Air being Generally by Judicious Men exploded as an Imaginary thing; And the Air not concurring to compose Mixt Bodies as one of their Elements, but only lodging in their pores, or Rather replenishing, by reason of its Weight and Fluidity, all those Cavities of bodies here below, whether compounded or not, that are big enough to admit it, and are not fill'd up with any grosser substance. And, to prevent mistakes, I must advertize You, that I now mean by Elements, as those Chymists that speak plainest do by their Principles, certain Primitive and Simple, or perfectly unmingled bodies; which not being made of any other bodies, or of one another, are the Ingredients of which all those call'd perfectly mixt Bodies are immediately compounded, and into which they are ultimately resolved: now whether there be any one such body to be constantly met with in all, and each, of those that are said to be Elemented bodies, is the thing I now question. By this State of the controversie you will, I suppose, Guess, that I need not be so absur'd [Errata: absurd] as to deny that there are such bodies as Earth, and Water, and Quicksilver, and Sulphur: But I look upon Earth and Water, as component parts of the Universe, or rather of the Terrestrial Globe, not of all mixt bodies. And though I will not peremptorily deny that there may sometimes either a running Mercury, or a Combustible Substance be obtain'd from a Mineral, or even a Metal; yet I need not Concede either of them to be an Element in the sence above declar'd; as I shall have occasion to shew you by and by.