PROCEEDINGS 1839 — 1840. 
79 
observations confirmed by some eucliometrical experiments of Dr. 
Priestley ; by the notion of Dr. Girtanner that atmospheric air was 
composed of oxygen and hydrogen gases in very near the same pro- 
portion as water ; and by additional experiments with the eudiometer 
by Mr. Humboldt. By the aid of these high authorities he satis- 
factorily concluded that the atmosphere is a chemical composition or 
solution of gases ; that it may be, and frequently is, composed of 
oxygen and hydrogen, the proportional parts of which are subject to 
considerable variation in different seasons and temperatures ; and 
hence together with the spontaneous evaporation of water, he deduces 
the principal cause of its greater or less fitness for the purposes of 
combustion, particularly as applied to the production of iron from 
the blast furnaces." The autlior went on to prove that this 
hypothesis from every point of view, is wholly inadmissible. He 
contended that the atmosphere is not a chemical, but a mechanical 
mixture of gases, and supported Mr. Daiton's theory of the properties 
of that mixture, "that mixed gases neither attract nor repel each 
other," and further quotes Mr. Henry's paper read to the Royal 
Society, that Daiton's theory is far better adapted than any former 
one for explaining the relation of mixed gases to each other, and 
especially the relation between gases and water, and consequently 
that the amount of gas absorbed by water depends altogether on the 
pressure applied. After stating the result of numerous experiments 
he advises the use of the hot air blast in furnaces for smelting iron as 
more economical than cold air. Mr. Hartop and others contended 
that iron made with the hot blast was inferior in strength, and that 
objects manufactured from it were much inferior in this respect to 
others made from cold blast iron. 
The tenth general meeting was held at Sheffield on the 4th 
June, 1840, and Mr. W. Bennett Martin, of Worsborough Hall, 
presided. Papers were read by Rev. W. Thorp ' On the disturbances 
in the district of the valley of the Don,' and an animated discussion 
arose as to whether they were due to a folding of the strata forming 
a synclinal trough, a latteral pressure, or a vertical pressure which 
had produced a fault, each theory having its exponent. Messrs. 
Morton and Holt produced a report on the proposed line of sections 
