1895 - 96 .] Prof. Crum Brown and Mr Fairbairn on Etthio , &c. 157 
Determination of sulphur in dietthiosuccinic ether. 
Weight of substance taken = ‘1315 gram. 
Weight of BaS0 4 obtained = *1992 gram. 
Calculated for C 12 H 22 S 2 0 4 . Found. 
S = 21 - 7. S = 20*8. 
Hence the reaction proceeded according to the following equa- 
tion — 
COOC 2 H 5 
COOC 2 H 5 
CHBr 
chsc 2 h 5 
CHBr +2C 2 H 5 S2s T a = 
1 
chsc 2 h 5 
+ 2NaBr. 
j 
COOCJL 
J 
cooc 2 h 5 
II. Action of Baryta on Dietthiosuccinic Ether. 
Dietthiosuccinic ether was boiled with the quantity of baryta 
required for barium dietthiosuccinate. When the solution became 
neutral, only about half of the ether was saponified. More baryta was 
added, and the solution was boiled till all the ether was saponified. 
Carbonic acid was passed through the cooled solution in order to 
convert the excess of baryta into barium carbonate. The gas 
evolved during the passage of the carbonic acid through the solu- 
tion, was passed through a solution of mercuric chloride, when the 
white compound of mercuric chloride and mercaptan was formed. 
The filtrate from the barium carbonate contained a very soluble 
barium salt, which, did not crystallise on evaporation. It was, 
however, insoluble in alcohol. On adding alcohol to the aqueous 
solution, the barium salt was precipitated as a white amorphous 
substance. 
Two barium estimations were made. 
(I.) Weight of substance taken 
Weight of BaS0 4 obtained 
Percentage of barium 
= *3606 gram. 
= *2696 gram. 
= 44 * 0 . 
(II.) Weight of substance taken 
Weight of BaS0 4 obtained 
Percentage of barium 
= *2725 gram. 
= ’2029 gram. 
= 43-8. 
