The doctrine of phlogiston established, and that of the composition of water refuted / by Joseph Priestley.

  • Priestley, Joseph, 1733-1804.
Date:
1800
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Licence: Public Domain Mark

Credit: The doctrine of phlogiston established, and that of the composition of water refuted / by Joseph Priestley. Source: Wellcome Collection.

Provider: This material has been provided by The Royal College of Surgeons of England. The original may be consulted at The Royal College of Surgeons of England.

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    rity of the gaffes, whereas with refpedl to mine, he fays, the purity was not tried. Now that of mine was not only tried, and with as great accuracy as they could try theirs, but the dephlogifticated air that I ufed was pu- rer than any that I believe they ever pretended to hav« made. For with two equal meafnres of iiitrous air, the refiduum was only four hundredth parts of a mea- fure, and this flight impurity was probably not in the dephlogifticated, but in the nitrous air. which is very apt to vary in its quality, and very difficult to obtain pure. And yet with this ver)', pure dephlogifticated air,, and a proportion, exaftly defined, of the pureft poflible inflammable air, I got drops of a ftronger a- cid than can be procured by means of air lefs pure. To this impurity, viz. a mixture of phlogifticated air, the antiphlogiftians always afcribe the produflion of the acid, though if the air be purpofely lefs pure, I never fail to find that impurity, viz. the phlogifticated air, unafFefted by the procefs ; fo that it could not pof- fibly have contributed to the production of the acid. With the greateft confidence, however. Dr. Ma :- lean fays, p. 53, the denfe acid vapour that I pro- daced by the cxplofion of the two kinds of air w is occafioned by the azote contained in the oxygenous gas that I employed. He might as well have fa 1 it was occafioned by that which I did not employ. li ten times the quantity of azote in the air I ufed h, 1 been wholly decompofed, it would not have amou, - ed to the hundredth part of the weight of the acid tl; t I procured. Their apparatus, he fays, was fo conftrufled, tl the refult could be determined with the greateft niccir. On the contrary, it was extremely complex, as a vit ^' of ^their plates will ftiew, and mine was pcrfe6lly fi;n- pie, fo that nothing can be imagined to be lefs liable ;o be a fource of error. How. indeed, was this pol'i- ble ? I ufc only one large vellcl, of glafs, or copper.