Essays of Jean Rey, doctor of medicine, on an enquiry into the cause wherefore tin and lead increase in weight on calcination. (1630) / Jean Rey.

  • Rey, Jean, -1645.
Date:
1895
Catalogue details

Licence: Public Domain Mark

Credit: Essays of Jean Rey, doctor of medicine, on an enquiry into the cause wherefore tin and lead increase in weight on calcination. (1630) / Jean Rey. Source: Wellcome Collection.

Provider: This material has been provided by The University of Glasgow Library. The original may be consulted at The University of Glasgow Library.

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    •sand which you throw into it and agitate, by moistening it and adhering to the smallest of its grains. I fancy there are many who would have been alarmed by the sole mention of this response if I had given it at the beginning, who will now willingly receive it, being as it -were tamed and rendered tractable by the evident truth ■of the preceding Essays. For those without doubt whose minds were preoccupied with the opinion that air was light, would have rushed to oppose it. Why (they would have said) does not one extract cold from heat, white from black, light from darkness, since so much heaviness is extracted from air, a thing inherently light ? And those who chanced to have bestowed their credence on the heaviness of air, would not have been able to persuade themselves that it can ever increase weight, being balanced in itself. On this account I was constrained to show that air had weight; which was recognisable by other means than the balance: and that even with the latter, a portion previously changed and made denser could manifest its weight. All this I have done as briefly as I found possible, and without advancing any- thing not strictly germane to this matter: to elucidate which at all points it only remains for me to state and refute succinctly some opinions which others have held or might hold; and 'to resolve the objections which might be made to my answer. ESSAY XVII. That it is not the disappearance of the celestial heat giving life to the lead, or the death of the latter, which augments its weight on calcination. Of all those whom I know to have written on this question, Cardan presents himself first, and asserts in the fifth book de Subtilitate that lead on conversion into