ACTION OF HEAT ON COMPOUNDS OF DIMETHYL-THETINE. aaa 
Action of Heat on Sulphate of Dimethyl-Thetine.—Having ascertained the 
nature of the decomposition which occurs when the hydrobromate of dimethyl- 
thetine is heated, I entertained but little doubt that the sulphate would suffer 
a similar change—that is to say, that it would split into sulphate of trimethyl- 
sulphine, sulphate of methyl, and thiodiglycollic acid, according to the equation— 
(CH,), 
$ CH,—COOH 
2| SO, = 2s6(CHL—_ COOH). | (CH,)s \ $0, + (CH,),S0, . 
S—CH,—COOH 
(OH), 
The experiment was made with the same apparatus as that employed for 
the hydrobromate, the manometer being retained in order that any sulphide of 
methyl produced by the dissociation of the sulphine compound might be the 
more readily condensed. 
The sulphate fused at about 140° C., and abundance of volatile products 
were disengaged. Some of these condensed in the receiver, but a large portion 
consisted of permanently gaseous substances, which escaped after the mercury 
in the manometer had risen above the full height of the tube. 
When this escape of gas had occurred once or twice it was thought worth 















while to collect it for examination. It was accordingly made to pass into wash 
bottles arranged as in the sketch.* 
The gas thus collected was in great measure absorbed after a few hours’ 
Tesidue was taken to be impure thiodiglycollic acid, and was only roughly examined to ascertain the 
presence of that substance. It is also possible that it was dissolved with the thiodiglycollic acid by 
the ether, and formed the oily liquid which saturated B3 after the ether had been evaporated off. 
The experiment, therefore, needs repeating. 
*T have found this form of apparatus exceedingly convenient, not only for storing up gases, but 
also for absorbing ammonia, hydrobromic acid, &c. It is especially useful for this purpose in deter- 
mining ammonia. 
