1819.] INstory of Anthrazothionic Acid. 101 
as will saturate 10 of oxygen. Now 10 oxygen require 1:327 of 
hydrogen, and in 49-04 anthrazothionic acid there are 2°19 of 
hydrogen. Hence 1:327 hydrogen must be contained in 29-71 
of acid. The number 29-71, therefore, is the equivalént for 
‘anthrazothionic acid ; and if from this number we subtract 1-327, 
or the hydrogen, the remainder 28°39 will be the equivalent for 
anthrazothion. Future experiments must determme whether 
anthrazothionic acid will be formed when Lampadius’s sulphuret 
of carbon and ammoniacal gas are made to pass over red hot 
potash. : 
ArticLe III. 
On the Sulphuretted Chyaxic Acid of Porrett.* By M. Vogel. 
WueEn Mr. Porrett, an English chemist, was occupied in 1808, 
with examining the reciprocal action of prussian blue and 
sulphuret of potash, he discovered sulphuretted chyazic acid 
he only set of experiments which has since appeared on this 
subject is contained in a memoir of M. Grotthuss of Courland.+ 
This chemist made a great number of experiments on this acid 
and its salts, from which he has drawn as a conclusion that 
Porrett’s acid is not composed of sulphur and prussic acid ;_ but 
rather of the elements of that acid united to sulphur in very 
different proportions. 
Formation of Sulphuretted Chyazic Acid. 
Mr. Porrett has pointed out different methods more or less 
complicated of obtaining this acid. The method of M. Grot- 
thuss seeming to me to present advantages, I repeated it by 
ealcining in a covered crucible a mixture of two parts of prussiate 
of potash and one part of sulphur. 
he black mass remaining in the crucible being boiled with 
alcohol of 38 degrees, gave a hquid, colourless after being 
filtered, which did not form prussian blue with the ferruginous 
salt, but communicated to them a dark cherry red colour. 
The alcoholic solution, however, was very alkaline. Muriatic 
acid disengaged from it sulphuretted hydrogen gas, and acetate 
of lead occasioned a black precipitate. Hence it contained 
otash partly disengaged and partly combined with sulphuretted 
ydrogen. By M. Grotthuss’s method then, we cannot obtain 
a pure sulphuretted chyazate, nor of consequence pure sulphu- 
retted chyazic acid ; for when the salt is mixed with diluted 
sulphuric acid and distilled, the acid which passes into the 
retort is contaminated with sulphuretted hydrogen. 
* Translated from the Journ, de Pharm, Oct. 1818, p. 441. 
+ A translation of this paper has just appeared in the Annals of Philosophy. 
