Robert Boyle (1627-1691)

The Sceptical Chymist

London, 1661, excerpts: [a long dialogue concerning the nature and number of the elements among Carneades (representing Boyle's opinions), Themistius (representing the four-element system of the ancients), Philoponus (representing the three-principle system of the alchemists), and Eleutherius (an interested bystander). Page references refer to the 1661 edition. --CJG]


The experiments wont to be employed to evince either the IV Peripatetick Elements, or the III Chymical Principles of Mixt Bodies
Part of the First Dialogue.


[pp. 13-17]

Philoponus and Themistius soon returned this complement with civilities of the like nature, in which Eleutherius perceiving them engaged, to prevent the further loss of that time of which they were not like to have very much to spare, he minded them that their present businesse was not to exchange complements, but Arguments: and then addressing his speech to Carneades, I esteem it no small happinesse (saies he) that I am come here so luckily this Evening. For I have been long disquieted with Doubts concerning this very subject which you are now ready to debate. And since a Question of this importance is to be now discussed by persons that maintain such variety of opinions concerning it, and are both so able to enquire after truth, and so ready to embrace it by whomsoever and on what occasion soever it is presented them; I cannot but promise my self that I shall before we part either lose my Doubts or the hopes of ever finding them resolved: Eleutherius paused not here; but to prevent their answer, added almost in the same breath; and I am not a little pleased to find that you are resolved on this occasion to insist rather on Experiments than Syllogismes. For I, and no doubt You, have long observed, that those Dialectical subtleties, that the Schoolmen too often employ about Physiological Mysteries, are wont much more to declare the wit of him that uses them, then increase the knowledge or remove the doubts of sober lovers of truth. And such captious subtleties do indeed often puzzle and sometimes silence men, but rarely satisfy them. Being like the tricks of Jugglers, whereby men doubt not but they are cheated, though oftentimes they cannot declare by what flights they are imposed on. And therefore I think you have done very wisely to make it your businesse to consider the Phaenomena relating to the present Question, which have been afforded by experiments, especially since it might seem injurious to our senses, by whose mediation we acquire so much of the knowledge we have of things corporal, to have recourse to far-fetched and abstracted Ratiocination, to know what are the sensible ingredients of those sensible things that we daily see and handle, and are supposed to have the liberty to untwist (if I may so speak) into the primitive bodies they consist of. He annexed that he wished therefore they would no longer delay his expected satisfaction, if they had not, as he feared they had, forgotten something preparatory to their debate; and that was to lay down what should be all along understood by the word Principle or Element. Carneades thank'd him for his admonition, but told him that they had not been unmindful of so requisite a thing. But that being Gentlemen and very far from the litigious humour of loving to wrangle about words or terms or notions as empty; they had before his coming in, readily agreed promiscuously to use when they pleased, Elements and Principles as terms equivalent: and to understand both by the one and the other, those primitive and simple Bodies of which the mixt ones are said to be composed, and into which they are ultimately resolved. And upon the same account (he added) we agreed to discourse of the opinions to be debated, as we have found them maintained by the Generality of the assertors of the four Elements of the one party, and of those that receive the three Principles on the other, without tying our selves to enquire scrupulously what notion either Aristotle or Paracelsus, or this or that Interpreter, or follower of either of those great persons, framed of Elements or Principles; our design being to examine, not what these or those thought or taught, but what we find to be the obvious and most general opinion of those, who are willing to be accounted Favourers of the Peripatetick or Chymical Doctrine, concerning this subject.

[pp. 347-352]


A Paradoxical Appendix to the Foregoing Treatise.
The Sixth Part.

Here Carneades Having Dispach't what he Thought Requisite to oppose against what the Chymists are wont to alledge for Proof of their three Principles, Paus'd awhile, and look'd about him, to discover whether it were Time for him and his Friend to Rejoyne the Rest of the Company. But Eleutherius perceiving nothing yet to forbid Them to Prosecute their Discourse a little further, said to his Friend, (who had likewise taken Notice of the same thing) I halfe expected, Carneades, that after you had so freely declar'd Your doubting, whether there be any Determinate Number of Elements, You would have proceeded to question whether there be any Elements at all. And I confess it will be a Trouble to me if You defeat me of my Expectation; especially since you see the leasure we have allow'd us may probably suffice to examine that Paradox; because you have so largly Deduc'd already many Things pertinent to it, that you need but intimate how you would have them Apply'd and what you would inferr from them.

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 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.

To give you then a brief account of the grounds I intend to proceed upon, I must tell you, that in matters of Philosophy, this seems to me a sufficient reason to doubt of a known and important proposition, that the Truth of it is not yet by any competent proof made to appear. And congruously herunto, if I shew that the grounds upon which men are perswaded that there are Elements are unable to satisfie a considering man, I suppose my doubts will appear rational.


[pp. 427-36]


These last Words of Carneades being soon after follow'd by a noise which seem'd to come from the place where the rest of the Company was, he took it for a warning, that it was time for him to conclude or break off his Discourse; and told his Friend; By this time I hope you see, Eleutherius, that if Helmonts Experiments be true, it is no absurdity to question whether that Doctrine be one, that doth not assert Any Elements in the sence before explain'd. But because that, as divers of my Arguments suppose the marvellous power of the Alkahest in the Analyzing of Bodies, so the Effects ascrib'd to that power are so unparallell'd and stupendious, that though I am not sure but that there may be such an Agent, yet little less than αυτοψια seems requisite to make a man sure there is. And consequently I leave it to you to judge, how farre those of my Arguments that are built upon Alkahestical Operations are weakened by that Liquors being Matchless; and shall therefore desire you not to think that I propose this Paradox that rejects all Elements, as an Opinion equally probable with the former part of my discourse. For by that, I hope, you are satisfied, that the Arguments wont to be brought by Chymists, to prove That all Bodies consist of either Three Principles, or Five, are far from being so strong as those that I have employ'd to prove, that there is not any certain and Determinate number of such Principles or Elements to be met with Universally in all mixt Bodies. And I suppose I need not tell you, that these Anti-Chymical Paradoxes might have been manag'd more to their Advantage; but that having not confin'd my Curiosity to Chymical Experiments, I who am but a young Man, and younger Chymist, can yet be but slenderly furnished with them, in reference to so great and difficult a Task as you impos'd upon me; Besides that, to tell you the Truth, I durst not employ some even of the best Experiments I am acquainted with, because I must not yet disclose them; but however, I think I may presume that what I have hitherto Discoursed will induce you to think, that Chymists have been much more happy in finding Experiments than the Causes of them; or in assigning the Principles by which they may best be explain'd. And indeed, when in the writings of Paracelsus I meet with such Phantastick and Un-intelligible Discourses as that Writer often puzzels and tyres his Reader with, father'd upon such excellent Experiments, as though he seldom clearly teaches, I often find he knew; me thinks the Chymists, in their searches after truth, are not unlike the Navigators of Solomons Tarshish Fleet, who brought home from their long and tedious Voyages, not only Gold, and Silver, and Ivory, but Apes and Peacocks too; For so the Writings of several (for I say not, all) of your Hermetick Philosophers present us, together with divers Substantial and noble Experiments, Theories, which either like Peacocks feathers make a great shew, but are neither solid nor useful; or else like Apes, if they have some appearance of being rational, are blemish'd with some absurdity or other, that when they are Attentively consider'd, makes them appear Ridiculous.

Carneades having thus finish'd his Discourse against the received Doctrines of the Elements; Eleutherius judging he should not have time to say much to him before their separation, made some haste to tell him; I confess, Carneades, that you have said more in favour of your Paradoxes than I expected. For though divers of the Experiments you have mention'd are no secrets, and were not unknown to me, yet besides that you have added many of your own unto them, you have laid them together in such a way, and apply'd them to such purposes, and made such Deductions From them, as I have not Hitherto met with.

But though I be therefore inclin'd to think, that Philoponus, had he heard you, would scarce have been able in all points to defend the Chymical Hypothesis against the arguments wherewith you have oppos'd it; yet me thinks that however your Objections seem to evince a great part of what they pretend to, yet they evince it not all; and the numerous tryals of those you call the vulgar Chymists, may be allow'd to prove something too.

Wherefore, if it be granted you that you have made it probable,

First, that the differing substances into which mixt Bodies are wont to be resolved by the Fire are not of a pure and an Elemenentary nature, especially for this Reason, that they yet retain so much of the nature of the Concrete that afforded them, as to appear to be yet somewhat compounded, and oftentimes to differ in one Concrete from Principles of the same denomination in another:

Next, that as to the number of these differing substances, neither is it precisely three, because in most Vegetable and Animal bodies Earth and Phlegme are also to be found among their Ingredients; nor is there any one determinate number into which the Fire (as it is wont to be employ'd) does precisely and universally resolve all compound Bodies whatsoever, as well Minerals as others that are reputed perfectly mixt.

Lastly, that there are divers Qualities which cannot well be refer'd to any of these Substances, as if they primarily resided in it and belong'd to it; and some other qualities, which though they seem to have their chief and most ordinary residence in some one of these Principles or Elements of mixt Bodies, are not yet so deducible from it, but that also some more general Principles must be taken in to explicate them.

If, I say, the Chymists (continues Eleutherius) be so Liberall as to make you these three Concessions, I hope you will, on your part, be so civil and Equitable as to grant them these three other propositions, namely;

First, that divers Mineral Bodies, and therefore probably all the rest, may be resolv'd into a Saline, a Sulphureous, and a Mercurial part; And that almost all Vegetable and Animal Concretes may, if not by the Fire alone, yet, by a skilfull Artist Employing the Fire as his chief Instrument, be divided into five differing Substances, Salt, Spirit, Oyle, Phlegme and Earth; of which the three former by reason of their being so much more Operative than the Two Later, deserve to be Lookt upon as the Three active Principles, and by way of Eminence to be call'd the three principles of mixt bodies.

Next, that these Principles, Though they be not perfectly Devoid of all Mixture, yet may without inconvenience be stil'd the Elements of Compounded bodies, and bear the Names of those Substances which they most Resemble, and which are manifestly predominant in them; and that especially for this reason, that none of these Elements is Divisible by the Fire into Four or Five differing substances, like the Concrete whence it was separated.

Lastly, That Divers of the Qualities of a mixt Body, and especially the Medical Virtues, do for the most part lodge in some One or Other of its principles, and may Therefore usefully be sought for in That Principle sever'd from the others.

And in this also (pursues Eleutherius) methinks both you and the Chymists may easily agree, that the surest way is to Learn by particular Experiments, what differing parts particular Bodies do consist of, and by what wayes (either Actual or potential fire) they may best and most Conveniently be Separated, as without relying too much upon the Fire alone, for the resolving of Bodies, so without fruitlessly contending to force them into more Elements than Nature made Them up of, or strip the sever'd Principles so naked, as by making Them Exquisitely Elementary to make them almost useless,

These things (subjoynes Eleu.) I propose, without despairing to see them granted by you; not only because I know that you so much preferr the Reputation of Candor before that of subtility, that your having once suppos'd a truth would not hinder you from imbracing it when clearly made out to you; but because, upon the present occasion, it will be no disparagement to you to recede from some of your Paradoxes, since the nature and occasion of your past Discourse did not oblige you to declare your own opinions, but only to personate an Antagonist of the Chymists. So that (concludes he, with a smile) you may now by granting what I propose, add the Reputation of Loving the truth sincerely to that of having been able to oppose it subtilly.

Carneades's haste forbidding him to answer this crafty piece of flattery; Till I shal (sayes he) have an opportunity to acquaint you with my own Opinions about the controversies I have been discoursing of, you will not, I hope, expect I should declare my own sence of the Arguments I have employ'd. Wherefore I shall only tell you thus much at present; that though not only an acute Naturalist, but even I my self could take plausible Exceptions at some of them; yet divers of them too are such as will not perhaps be readily answer'd, and will Reduce my Adversaries, at least, to alter and Reform their Hypothesis. I perceive I need not minde you that the Objections I made against the Quaternary of Elements and Ternary of Principles needed not to be oppos'd so much against the Doctrines Themselves (either of which, especially the latter, may be much more probably maintain'd than hitherto it seems to have been, by those Writiers for it I have met with) as against the unaccurateness and the unconcludingness of the Analytical Experiments vulgarly Relyed On to Demonstrate them.

And therefore, if either of the two examin'd Opinions, or any other Theory of Elements, shall upon rational and Experimental grounds be clearly made out to me; 'Tis Obliging, but not irrational, in you to Expect, that I shall not be so farr in Love with my Disquieting Doubts, as not to be content to change them for undoubted truths. And (concludes Carneades smiling) it were no great disparagement for a Sceptick to confesse to you, that as unsatisfy'd as the past discourse may have made you think me with Doctrines of the Peripateticks, and the Chymists, about the Elements and Principles, I can yet so little discover what to acquiesce in, that perchance the Enquiries of others have scarce been more unsatisfactory to me, than my own have been to my self.


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