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

  • Priestley, Joseph, 1733-1804.
Date:
1894
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Licence: Public Domain Mark

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

Provider: This material has been provided by UCL Library Services. The original may be consulted at UCL (University College London)

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    common air by nitrous air. At another time, the air which I extracted from this substance was not diminished by nitrous air quite so much as common air is. N.B. The quantity of air was ahvays very small, not more than the bulk of the materials. From the Roman vitriol I also got but a small quantity of air. The first that I got was diminished by nitrous air, exactly as much as common air. I repeated the experiment, and the air which I then got was diminished by nitrous air considerably more than common air. The result of these experiments rather surprizes me, as, after many trials made with a view to it, I could get no such air from any species of factiiious vitriol, calcined or uncalcined. There must certainly have been some nitrous acid in that Roman vitriol. The readers of my former publications on this subject will remember, that I was exceedingly puzzled with the experiments which I made to extract air from salt-petre in a gun-barrel; the results appearing to me very extra- ordinary, and well worth attending to, as they might lead to considerable discoveries. (Vol. I. p. 155.) In fact, there was sufficient reason for the conjecture; but the method which I then took to extract air from this substance was ill adapted to make it yield its genuine produce. I had not, however, at that time, thought of any other. The air I first got admitted a candle to burn in it with a very strong flame, and with a crackling noise. Also, though, after having stood a whole year in water, it became quite noxious, yet by agitation in fresh water, it was perfectly restored; so that a candle would burn in it again. At the time of my last publication, I con- jectured that this air was phlogisticated fiitrous air; but now I think it must have been dephlogisticated air, though produced in a gun-barrel, in which the spirit of