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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    some aerated particles, would it not decrease in volume ? On the contrary it increases. And again, why do not stones and plants increase in weight on calcination if that reason be valid ? I infer from the above that the consumption of aerated particles never augments the weight of things when shrinkage does not result; which not being the case in our affair, cannot be admitted as the cause of the surplus weight of which I discourse. I add in conclusion that the air w^ich. is forced by a syringe into a globe already full of it, diminishes the weight on escaping, far from increasing it as Scaliger fancies. It is true that this is met with only in this one case. ESSAY XIX. That it is not soot which augments the weight of the calx. I read in the tenth chapter of the sixth book of the Chemical Arcana by Libavius (for I have not seen it else- where) that Caesalpinus has written, that it is a remarkable thing that lead on calcination increases in weight by eight or ten pounds per cent. Then, seeking the cause, he says that it is due to the soot which the fire produces striking the vault of the furnace and by reflection falling back on the substance. This Csesalpinus would never have advanced had he paid attention to what I am about to deduce. Firstly, the soot on being exhaled by the fire is of so rare a nature, that the seven ounces of increase found by the sieur Brun would occupy more space than all the calx he derived from the calcination. In the second place, this abundance of soot would so blacken the calx of tin or lead, that the Ladies would never borrow from it the whiteness of their complexions, as several do. And again, what would hinder the quantity of this calx from being infinitely increased, since the fire