sg M. Grotthuss on the ; [Fes. 
of the acid and the salt. The tube was now shut, removed from 
the mercury, washed on the outside with water, and plunged 
into a glass vessel filled with distilled water,. A, in order to free 
it from the small quantity of mercury which it contained, and 
-from the acid magma which floated over the mercury. These 
being removed, the mouth of the tube was again shut, and it 
was introduced into lime water, and left in it. The lime water 
made its way visibly into the tube, and became quite milky, and 
the tube, being agitated, was in about 15 minutes completely 
filled, so that not even a trace of gas remained unabsorbed (for a 
residue of azote might have been expected). The precipitate 
which fell in the lime water consisted of carbonate and sulphite 
of lime. The lime water had likewise absorbed undecomposed 
anthrazothionic acid, and struck a yellowish red colour with a 
solution of iron. The distilled water A contained not only sul- 
phuric acid and a portion of precipitated sulphur, but likewise 
sulphate of ammonia; for being heated and mixed with an excess 
of potash ley, it emitted a strong smell of ammonia. This 
experiment was several times repeated, and always gave the 
same result. It follows from it obviously that anthraxothionic 
acid either contains ammonia as a constituent, or at least hydrogen 
and azote in the exact proportion requisite for forming ammonia. 
Sect.21.—I have in vain attempted by a similar mode of 
decomposition to separate the azote in a gaseous form from 
anthrazothionic acid. When I put anthrazothionhydrate of 
copper mixed with chlorate of potash into the tube, and added 
muriatic acid to the mixture, | obtained, it is true, from 1 gr. 
of the hydrate, after the other gases had been absorbed, a quan- 
tity of azotic gas, which, at the common temperature of the 
atmosphere, and when the barometer stood at 30 inches, was 
equivalent to 18°5 er. of water; but muriate of ammonia was 
found in the residual sour liquid, and by calculation, founded on 
the subsequent stochiometrical construction, 1 found that only , 
4a of the azote in the acid had been evolved in the gaseous 
state. The constituents of this acid might be most easily and 
accurately ascertained by means of Volta’s eudiometer. But for 
this purpose not merely a convenient mercurial apparatus is 
requisite, but likewise an eudiometer attached to the mercurial 
trough. Now as I happen not to possess any such, I am under 
the necessity of employing a more tedious, but not less accurate 
method of determining these constituents. 
Sect. 22.—We have now found two facts which are of import- 
ance towards the determination of the constitution of anthrazo- 
thionic acid; namely, the ratio of the sulphur to the carbon, 
and that of the azote to the hydrogen. Now to find the ratio of 
one of the former of these bodies to one of the latter, by which 
the ratio of all the four constituents to each other is ascertained, 
and consequently the analysis of the acid completed, nothing 
more is requisite than to determine the absolute weight of one 
s] 
