Foundations of the atomic theory : comprising papers and extracts / by John Dalton, William Hyde Wollaston, and Thomas Thomson.

Date:
1893
Catalogue details

Licence: Public Domain Mark

Credit: Foundations of the atomic theory : comprising papers and extracts / by John Dalton, William Hyde Wollaston, and Thomas Thomson. Source: Wellcome Collection.

Provider: This material has been provided by the Royal College of Physicians of Edinburgh. The original may be consulted at the Royal College of Physicians of Edinburgh.

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    temperature. For, the weight of each gas in any given portion of atmospheric air, must be in the compound ratio of its force and specific gravity. With respect to the third object, it may be observed, that those gases which are specifically the heaviest must decrease in density the quickest in ascending. If the earth's atmosphere had been a homogeneous elastic fluid of the same weight it is, but ten times the specific gravity, it might easily be demonstrated that no sensible portion of it could have arisen to the summits of the highest mountains. On the other hand, an atmosphere of hydro- genous gas, of the same weight, would support a column of mercury nearly 29 inches on the summit of Mount Blanc. The several gases constantly found in every portion of atmospheric air, and in such quantities as are capable of being appreciated, are azotic, oxygenous, aqueous vapour, and carbonic acid. It is probable that hydro- genous gas also is constantly present; but in so small proportion as not to be detected by any test we are acquainted with; it must therefore be confounded in the large mass of azotic gas. 1. Of the Weight of the Oxygenous and Azotic Atmospheres. Various processes have been used to determine the quantity of oxygenous gas. 1. The mixture of nitrous gas and air over water. 2. Exposing the air to liquid sulphuret of potash or lime, with or without agitation. 3. Exploding hydrogen gas and air by electricity. 4. Exposing the air to a solution of green sulphat or muriat of iron in water, strongly impregnated with nitrous gas.