of Earth. If I spoke (continues Themistius) to less knowing Persons, I would perhaps make some Excuse for building upon such an obvious and easie Analysis, but ’twould be, I fear, injurious, not to think such an Apology needless to You, who are too judicious either to think it necessary that Experiments to prove obvious truths should be farr fetch’d or to wonder that among so many mixt Bodies that are compounded of the four Elements, some of them should upon a slight Analysis manifestly exhibite the Ingredients they consist of. Especially since it is very agreeable to the Goodness of Nature, to disclose, even in some of the most obvious Experiments that Men make, a Truth so important, and so requisite to be taken notice of by them. Besides that our Analysis by how much the more obvious we make it, by so much the more suitable it will be to the Nature of that Doctrine which ’tis alledged to prove, which being as clear and intelligible to the Understanding as obvious to the sense, tis no marvel the learned part of Mankind should so long and so generally imbrace it, For this Doctrine