Pal 
eae 
ACTION OF HEAT ON COMPOUNDS OF DIMETHYL-THETINE. 599 
hydrobromate is decomposed in quite a different manner from the sulphate, it 
appeared to be of interest to extend the experiment to the hydrate, in order to 
ascertain which of the two kinds of decomposition it would suffer when heated. 
If it behaved as the hydrobromate, then hydrate of trimethyl-sulphine (or methyl 
alcohol and sulphide of methyl) would be produced together with thiodigly- 
collic acid; whereas if it behaved as the sulphate, the products would be car- 
bonate of trimethyl-sulphine and carbonic anhydride. 
A quantity of the hydrate (well dried in a desiccator) was heated in a distil- 
ling flask placed in an oil-bath. It fused easily, and gaseous products 
were at once evolved. ‘That these contained considerable quantities of sulphide 
of methyl was proved by passing them through alcoholic solution of corrosive 
sublimate, when the characteristic white crystalline precipitate was produced. 
That they also contained large quantities of carbonic anhydride was shown by 
the abundant white precipitate which occurred when they were allowed to 
bubble through baryta water. 
As soon as no further disengagement of volatile products occurred, the ex- 
periment was stopped, and the syrupy liquid which remained examined. 
It effervesced violently when mixed with hydrochloric acid, the gas given 
off consisting of carbonic anhydride. The resulting solution gave a sparingly 
soluble crystalline salt with chloride of platinum, which was proved by a 
platinum determination to consist of chloro-platinate of trimethyl-sulphine— 
Ie Il. Theory. 
Platinum : : , 345 34:8 34:9. 
No thiodiglycollic acid could be detected. 
The reaction which occurs when the hydrate of dimethyl-thetine is heated 
is therefore similar to that which the sulphate suffers, and is expressed by the 
following equation :— 
CH, 
2 HO—S—CH,— COOH = ({C(SCH,),},CO, + H,O + CO. 
) 
CH, 
The sulphide of methyl no doubt arises (as in the case of the sulphate of 
dimethyl-thetine) from the dissociation of the sulphine compound. 
The preceding experiments show that the salts of ee suffer 
one of two distinct decompositions when heated. 
Either they are resolved into thiodiglycollic acid and a sulphine compound— 
as in the case of the hydrobromate; or they split into carbonic anhydride and a 
sulphine compound—as in the cases of the sulphate and hydrate. When this 
latter decomposition occurs, the carbonic anhydride separates from the glycolyl 
VOL. XXVIII. PART II. 7Q 
