44 ML. Grotthuss on the [Jan. 
acid ; for in all cases in which this acid was decomposed 
means of sulphuric acid, or chloriie, I have been able at last to 
detect the presence of ammonia by means of potashley. Strong 
white clouds made their appearance, when a feather dipped in 
acetic acid was held over the liquid, and the ammonia at last 
became sensible by its smell. We might, perhaps, conclude, 
that when the anthrazothionic acid was decomposed, the water 
of the acid employed to decompose it (chlorine or sulphuric acid) 
supplied the hydrogen for the formation of the ammonia by 
uniting with the azote of the anthrazothionic acid, while the 
oxygen of the water might unite with the carbon of that_acid 
and form carbonic acid; but in that case common muriatic acid 
must be capable of producing the same decomposition. Nowas 
this is not the case, I conclude that the hydrogen which goes to 
the formation of ammonia during the decomposition cannot have 
been furnished by the water; but must undoubtedly have exzsted 
in the anthrazothionic acid itself together with the axote in the 
wery proportion adapted for the formation of ammonia. 
Sect. 9.—If a concentrated solution of anthrazothionate of 
potash in water be exposed to the action of a good Voltaic bat- 
tery, a great evolution of gas takes place at the negative pole. 
This gas has a peculiar smell, similar to that of the inflammable 
gas from marshes. It is itself combustible, and when bummed, 
carbonic acid gas is formed, and there remains a residuum of 
azotic gas. I consider this gas as a triple compound of carbon, 
hydrogen, and azote ; though indeed it may be only a mixture 
of carburetted hydrogen and azotic gas. At the positive pole no 
gas is extricated ; the liquid from the sulphur contained in it 
becomes yellowish, and at last allows the greater part of the 
sulphur to precipitate in large flocks. If silver or any other 
easily sulphuretted metal be placed in contact with the positive 
pole, it becomes immediately black by entering into combination 
with the sulphur; at the negative pole it remains completely 
white. It is possible that it may form a hydrate there, though 
the supposition is not very probable. The liquid, after having 
been exposed for some hours to the action of a battery of 100 
pair of round plates, nine inches in diameter, was tried at both 
poles to discover in it the presence of prussic acid, nitric acid, 
and ammonia; but not a trace of one of these bodies could be 
found. The liquid from both poles, when mixed with a solution 
of iron in an acid, struck a blood-red colour, which must be 
ascribed to the presence of undecomposed anthrazothionate of 
potash. The sulphur at the beginning of the process remained 
in. solution at the positive pole, and gave the liquor a yellow 
colour. This shows us that anthrazothionic acid is capable of 
existing with two proportions of sulphur, namely, a minimum, 
and a maximum. {In this last state it must form peculiar com- 
pounds with the bases, which deserve hereafter to be accurately 
examined. If, as Porrett supposes, the acid were a compound 
