ADVERTISEMENTS About the EXPERIMENTS AND NOTES Relating to CHYMICAL Qualities.

WHen, after I had gone through the common Operations of Chymistry, I began to make some serious Reflections on them, I thought 'twas pity, that Instruments that might prove so serviceable to the advancement of Natural Philo∣sophy, should not be more studiously and skilfully made use of to so good a purpose.

I saw indeed, that divers of the Chymists had by a diligent and laudable employment of their pains and industry, obtain'd divers Productions, and lighted on several Phaenomena considerable in thier kind, and indeed more numerous, than, the narrowness and sterility of their Principles consider'd, could well be expected.

But I observed too, that the generality of those that busie themselves about Chymical O∣perations; some because they pra∣ctise Physick; and others because they either much wanted, or gree∣dily coveted money, aimed in their Trials but at the Preparation of good Medicines for the humane bo∣dy, or to discover the ways of cu∣ring the Diseases or Imperfections of Metals, without referring their Tri∣als to the advancement of Natural Philosophy in general; of which most of the Alchymists seem to have been so incurious, that not onely they did not institute Experiments for that purpose, but overlookt and despis'd those undesign'd ones that occurr'd to them whilst they were prosecuting a preparation of a Me∣dicine, or a Transmutation of Me∣tals.

The sense I had of this too ge∣neral omission of the Chymists, tem∣pted me sometimes to try, whether I could do any thing towards the re∣pairing of it by handling Chymistry, not as a Physician or an Alchymist, but as a meer Naturalist, and so by applying Chymical Operations to Philosophical purposes.

And in pursuance of these thoughts, I re∣member I drew up a Scheme of what I ventur'd to call a Chymia Philoso∣phica, not out of any affectation of a splendid Title, but to intimate, that the Chymical Operations, there treated of, were not directed to the usual scopes of Physicians, or Trans∣muters of Metals, but partly to il∣lustrate or confirm some Philosophi∣cal Theories by such Operations; and partly to explicate those Opera∣tions by the help of such Theo∣ries.

But before I had made any great progress in the pursuit of this de∣sign, the fatal Pestilence that raged in London, and in many other parts of England, in the years 1664 and 65, obliging me among the rest to make several removes; which put me upon taking new measures, and engaging me in other employments of my time, made me so long neglect the Papers I had drawn up, that at last I knew not where to finde them, (though I hope they are not yet mislaid beyond recovery,) which I was the less troubled at, because the great difficulties, to be met with in such an undertaking, did not a little discourage me, such a Task requi∣ring as well as deserving a Person better furnished, than I had reason to think my self, with Abilities, Lei∣sure, Chymical Experiments, and Conveniences, to try as many more as should appear needful.

But yet to break the Ice for any that may hereafter think fit to set upon such a Work, or to shorten my own La∣bour, if I should see cause to resume it my self, I was content to throw in among my Notes about other Parti∣cular Qualities, some Experiments and Observations about some of those, that I have elsewhere call'd Chymical Qualities, because 'tis chief∣ly by the Operations of Chymists, that men have been induced to take special notice of them.

Of these Notes I have assigned to some Qua∣lities more, and to some fewer, as either the nature or importance of the Subject seemed to require, or my Leisure and other Circumstan∣ces would permit.

And though I have not here handled the Subjects they belonged to, as if I intended such a Chymia Philosophica as I late∣ly mentioned, because my design did not make it necessary, but did perhaps make it impertinent for me to do so, yet in some of the larger Notes about Volatility and Fixtness, and especially about Precipitation, I have given some little Specimens of the Theorical part of a Philosophi∣cal Account of those Qualities or Operations, that I hope will not be wholly useless.

I know, it may be objected, that I should have employ∣ed for Instances some more consider∣able Experiments, if not Arcana; but though possibly I am not alto∣gether unfurnished with such, yet aiming rather to promote Philoso∣phy, than appear a Possessor of ela∣borate Processes, I declined several Experiments that required either more skill, or more time, or more expence than could be well expect∣ed from most Readers, and chose rather to employ such Experiments as may be more easily or cheaply tried, and, which is mainly to be consider'd, being more simple, are more clearly intelligible, and more fit to have Notions and Theories built upon them; especially considering, that the Doctrine of Qualities being it self conversant about some of the Rudimental parts, if I may so call them, of Natural Philosophy, it seemed unfit to employ intricate Ex∣periments, and whose Causes were liable to many disputes, to settle a Theory of them.

In short, my de∣sign being to hold a Taper not so much to Chymists as to the Natu∣ralists, 'twas fit I should be less soli∣citous to gratifie the former than to inform the later.

FINIS.