When I said, _without very much Inconvenience_, I had in my Thoughts that sober Admonition of _Galen_, _Cum de re constat, de verbis non est Litigandum_. And therefore also I scruple not to say _Elements_ or _Principles_, partly because the Chymists are wont to call the Ingredients of mixt Bodies, _Principles_, as the _Aristotelians_ name them _Elements_; I would here exclude neither. And, partly, because it seems doubtfull whether the same Ingredients may not be call'd _Principles_? as not being compounded of any more primary Bodies: and _Elements_, in regard that all mix'd Bodies are compounded of them. But I thought it requisite to limit my Concession by premising the words, _very much_, to the word _Inconvenience_, because that though the Inconvenience of calling the distinct Substances, mention'd in the Proposition _Elements_ or _Principles_, be not very great, yet that it is an Impropriety of Speech, and consequently in a matter of this moment not to be altogether overlook'd, You will perhaps think, as well as I, by that time you shall have heard the following part of my Discourse, by which you will best discern what Construction to put upon the former Propositions, and how far they may be look'd upon, as things that I concede as true, and how far as things I only represent as specious enough to be fit to be consider'd. And now _Eleutherius_ (continues _Carneades_) I must resume the person of a Sceptick, and as such, propose some part of what may be either dislik't, or at least doubted of in the common _Hypothesis_ of the Chymists: which if I examine with a little the more freedom, I hope I need not desire you (a Person to whom I have the Happinesse of being so well known) to look upon it as something more suitable to the Employment whereto the Company has, for this Meeting, doom'd me; then either to my Humour or my Custom. Now though I might present you many things against the Vulgar Chymical Opinion of the three Principles, and the Experiments wont to be alledg'd as Demonstrations of it, yet those I shall at present offer you may be conveniently enough comprehended in four Capital Considerations; touching all which I shall only premise this in general, That since it is not my present Task so much to assert an _Hypothesis_ of my own, as to give an Account wherefore I suspect the Truth of that of the Chymists, it ought not to be expected that all my Objections should be of the most cogent sort, since it is reason enough to Doubt of a propos'd Opinion, that there appears no cogent Reason for it. To come then to the Objections themselves; I consider in the first place, That notwithstanding what common Chymists have prov'd or taught, it may reasonably enough be Doubted, how far, and in what sence, Fire ought to be esteem'd the genuine and universal Instrument of analyzing mixt Bodies.