1819.] History of Anthrazothionic Acid. 9) 
ing the chemical process ; for muriate of barytes threw down a 
precipitate in it, which, when collected, washed, dried, and heated 
to redness in a watch-glass upon Guyton’s lamp apparatus, 
weighed 4:1 gr. To this must be added +,th gr. of the precipitate 
which remained behind upon the filter; for the weight of the 
filter was increased by a little more than =4th grain; but I 
restrict it to that quantity on account of the moisture which 
could not be completely dissipated on the filter. Hence we ma 
reckon the weight of the sulphate of barytes formed 4:2 gr. 
which is equivalent to 0°57 gr. of sulphur. Of consequence the 
quantity of sulphur obtained by the decomposition of the anthra- 
zothionic acid amounted to 2°57 gr. 
Sect. 19.—The precipitate which was formed in the lime 
water being collected, washed, dried, and weighed, was found 
to amount to 2°85 gr. Diluted acetic acid dissolved it with 
effervescence, carbonic acid gas being evolved; but there 
remained behind a very small quantity of a white powder, which 
after being washed and dried could not be weighed. A drop of 
sulphuric acid being let fall upon it, the odour of sulphurous acid 
became evident. Hence it appears that a little sulphite had been 
formed at the same time with the carbonate ; so that sulphurous 
acid had: been given out as wellas carbonic acid. As the acetic 
acid and the edulcorating water must have dissolved a portion of 
this sulphite, we cannot err very much if we consider it as equal 
to O:1l gr. This being subtracted from the weight of the car- 
bonate, leaves 2°74 gr.; but 0-11 gr. of sulphite of hme are nearly 
equivalent to.0°03 sulphur. Hence the sulphur in the portion of 
acid subjected to experiment was 2°57 + 0:03 = 2°6 gr. ; and 
2°74 gr. of carbonate of lime are an equivalent for 0°328 gr. of 
carbon. It follows from this, that in anthrazothionic acid the 
sulphur bears to the carbon the proportion of 2-6 : 0-328. It 
was the object of the preceding experiment to find this ratio. 
Sect. 20.—Into a glass tube hermetically sealed at the under 
end, [ put a small portion of dry crystallized anthrazothioniate of 
potash, and filled up the rest of the tube, except a very small 
space, with mercury. The friction against the sides of the tube 
prevented the salt from leaving the bottom and being buoyed up 
to the top of the tube. By agitation and by the proper applica- 
tion of heat, I at last drove every trace of atmospherical air out 
of the tube. I now filled the residual portion of the tube with: 
sulphuric acid, shut its mouth with the finger, and, turning it 
upside down, introduced it into a vessel filled with mercury, and 
then removed the finger. The sulphuric acid, from its liquidity, 
and the greater specific gravity of the mercury, must of course 
make its way to the upper part of the tube, and come in contact 
with the salt. Heat being applied to the outside of the tube, it 
was at last almost completely filled with gas extricated from the 
decomposed anthrazothionic acid, so that only a few drops of 
mercury remained in it, over which floated the magma composed: 
