1814.] Constituents of Azoie. 261 



when it is procured from the sulphuret of iron, were passed through 

 a red-hot copper tube. 



4 4 4 4 5 



Wevvill suppose H O + SH + H passed on; one S is depo- 

 sited either in combination with the copper, or separated and sub- 



limed on the colder part of the tube. O S form one sulphuric acid 



1 G l 



that is absorbed by the water. O combines with H to form A, 



2 3 4 



which enters into combination with S and H. H are left in an 

 uncombined state. Now the gases received over water are found to 

 consist of 4 per cent, oxygen, 52 hydrogen, and 44 unknown gas, 

 possessing similar properties to azote. These gaseous products will 

 be found to agree with the foregoing deduction, the small portion 

 of oxygen being considered as accidental, or as derived from the 



2 3 



water. The symbol of the unknown gas, then, is A S H. 



4 4 4 4 £ 3 



The H O -f S H + H are thus resolved : S and O S are con- 



2 3 4 



densed, while ASH and H are received over water in a permanent 

 state. 



These gases, in consequence of some internal change of affini- 

 ties, become condensed in time to nearly half their volume. Small 

 regular crystals deposited themselves on the sides of the vessel, and, 

 at the periods of opening the stop-cock, atmospheric air rushed in to 

 supply the vacuum produced by the condensation of the contents. 

 The gas became changed in its properties. It had acquired a 

 peculiar fetid smell ; and although so large a portion of oxygen was 

 admitted in the atmospheric air, it seemed all absorbed in its new 

 combination, as not one particle was to be discovered by any of the 

 known modes of detecting its presence. Notwithstanding also that 

 a very large portion of hydrogen had originally existed in the gaseous 

 product, none was now discoverable in it, but by some chemical 

 change, which let free a part from its combination. A peculiar 

 acid gas was now found to exist in the gas, possessing very peculiar 

 properties. This acid gas existed in a state of combination with the 

 hydrogen, which it threw off whenever it entered into new combi- 

 nations. A portion of the azote of the atmospheric air, admitted 

 into the flask, was also found to have, entered into the composition 

 of the acid gas. The quantity of atmospheric air admitted into the 



4 2 1 



flask i> to be represented by A O (two atoms), S having been pre- 

 viously deposited in the crystals. 



... on examination, the mixed gas in the flask is found to 

 ol about 48 - 7 acid gas, l.V. i hydrogen, and 86 azote, per 



Hence we may ascertain the state of this change: AO + 

 « i • * s a 



A Mi + H - S are resolved into (S () A 11 + II) + .A. The 



