The discovery of oxygen, part 1 / Experiments by Joseph Priestley, LL.D. (1775).

  • Priestley, Joseph, 1733-1804.
Date:
1901
Catalogue details

Licence: In copyright

Credit: The discovery of oxygen, part 1 / Experiments by Joseph Priestley, LL.D. (1775). Source: Wellcome Collection.

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    reduced it to one third of what it was at first, and nearly three times its bulk of nitrous air made very little addition to its original dimensions ; so that this air was exceed- ingly pure, and better than any that I had procured before. The preparation called massicot (which is said to be a state between the grey calx and the red lead) also yielded a considerable quantity of air, of which about one half was fixed air, and the remainder was such, that when an equal quantity of nitrous air was put to it, it was some- thing less than at first; so that this air was about twice as pure as common air. I thought it something remarkable, that in the pre- parations of lead by heat, those before and after these two, viz. the red lead and massicot, yielded only fixed air. 1 would also observe, by the way, that a very small quantity of air was extracted from lead ore by the burning lens. The bulk of it was easily absorbed by water. The remainder was not affected by nitrous air, and it extinguished a candle. I got a very little air by the same process from the grey calx of lead, of precisely the same quality with the former. That part of it which was not affected by nitrous air extinguished a candle, so that both of them may be said to have yielded fixed air, only with a larger portion than usual, of that part of it which does not unite with water. Litharge (which is a state that succeeds the red lead) yielded air pretty readily; but this also was fixed air. That which was not absorbed by water, was not affected by nitrous air. Much more than I had any opportunity of doing remains to be done, in order to ascertain upon what circumstances, in these preparations of lead, the quality of the air which they contain, depends. It can only be