382 Scientific Intelligence.— Chemistry. 
11. Action of Potash on Organic Materials.—The success of 
Vauquelin in converting pectic acid to oxalate of potash, by heating 
the former in a crucible with potash, induced Gay Lussac to attempt 
the conversion of other organic matters to oxalic acid by a similar 
PrOCeRBe dy "e8 
Five grains of cotton, were put into a platina crucible with twenty 
five grains of alcoholic potash, and a little water, and the mixture 
heated over an alcoholic lamp. The cotton resisted the action for 
some time, but at length yielded, softened, swelled, and evolved hy- 
drogen. It was necessary to stir the mass continually.. When the 
action is over, the mass is dissolved in a little water and slightly su- 
persaturated with nitric acid ; it then gives with nitrate of lead, an 
abundant precipitate, which treated by hydro-sulphuric:acid, produces 
beautiful crystals of oxalic acid. With the nitrate of lime, a volumin- 
ous precipitate is had of oxalate of lime. 
» Wood saw dust gave a similar result. 
> Sugar, starch, gum, and sugar of milk, treated with potash, fur- 
nished in like manner oxalate of potash. grey do 
-» Tartaric acid also underwent this remarkable transformation, with- 
out tumescence, blackening or giving out any considerable portion 
of hydrogen. 
» Citric and mucic acid produced much oxalic acid. : 
_. Silk, treated with potash, afforded oxalic acid, with a disengage- 
ment of hydrogen. 
~ Uric acid and gelatine also furnished it. Indigo did not.—Ann. 
de Chimie. Aout, 1829. 
12. Composition of the Atmosphere.—M. Kurrrer, in a letter to 
Arago, states, that in Civilized Europe it might be foreseen that any 
slight difference of composition in the air would be soon destroyed by 
the winds, as those countries are but a few hundred leagues apart; 
but Kazan, which is bounded on one side by an uncultivated country, 
_ and on the other by the immense steppes and forests of Siberia, 
where. there is no vegetation during the greater part of the year; 
might be imagined to have an atmosphere somewhat different from 
the rest of Europe. Employing the Eudiometer of Volta, 193 parts 
of atmospheric air, mingled with 99 of hydrogen, gave constant 
_ 1471 to.172 parts after detonation, which gives 20. to 21.2 of oxy- 
_ gen in 100 parts of air. The greatest care was observed with re- 
aperature and pressure.—Idem. 
