An essay on phlogiston, and the constitution of acids / [Richard Kirwan].

  • Kirwan, Richard, 1733-1812.
Date:
1787
Catalogue details

Licence: Public Domain Mark

Credit: An essay on phlogiston, and the constitution of acids / [Richard Kirwan]. Source: Wellcome Collection.

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    / ed, as they were never able to exhibit this fubftance fingly and by Itfelf, for which in¬ ability they accounted by faying, that on quitting one body it always united to another* With this reafoning 1110ft chymifts acquiefced, and the rather, as they found it impoffible to fubftitute a better theory in its place. Even the weight which many metallic fubftances were known to gain when they were faid to have loft their phlogifton, did not for a long time fhake the credit of this favourite hypo¬ thecs : it was held by fome, that this increafe of weight was owing to the acceffion of igneous particles ; by others, that phlogifton was a principle of levity. Rey, in the laft century, afcribed it to its true caufe, the abforption of air, but on fuch weak grounds, that he is as little intitled to the honour of a difcoverer, as a fuccefsful dreamer to that of a prophet: nor can I with juftice afcribe this honour to Dr. Hales, though he firft extracted air from minium ;, as he imputed the increafe of weight not only to the air, but alfo to fulphur, which he imagined it abforbed from the fire. Mr. Lavoifier was undoubtedly the fi rft who proved, by diredt and exadt experiments, that the weight which metals gain by calcination correfponds with that of the air which they abforb ; he was alfo the firft who publiftied that the at- mofphere confifts of two diftindt fluids, the one fit for the purpofes of refpiration and com- biiftion, which he therefore calls vital ox pure B 2 air ;