592 DR E. A. LETTS ON THE 
120° C., the thetine salt began to bubble, and the decomposition increased in 
rapidity with rise of temperature. The heating was continued for some hours, 
the final temperature being from 150° to 160° C. The contents of the limb 
B—which at the close of the experiment consisted of a clear liquid—solidified 
during the night to a colourless crystalline mass. 
B was cut* off and placed for a day or two in a desiccator, in order that any 
sulphide of methyl might escape. The crystals contained bromine, and on deter- 
mining its amount it was found to agree with that required for the bromide of 
trimethyl-sulphine. Assuming the decomposition of the thetine compound to 
be such that this body is produced, it appeared possible that its formation 
might be attended with that of substances analogous to HEINnTz’s diglycol- and 
triglycol- amidic acids, which are formed along with glycocoll by the action of 
ammonia on bromacetic acidt— 
jal 
| 
N—CH,—CO,H 
| 
i 
Glycocoll. ( S 
| 
oe. CH,—CO,H 
N—On—COLE Thioglycollic Acid. $ 
2 2 
| 
H 
Diglycol-amidic Acid. 
CH,—CO,H cage 
| 
N—CH,—CO,H ; 
| 
CH,—CO,H CH,—CO,H 
Triglycol-amidic Acid. Thiodiglycollic Acid. 
The formation of thioglycollic acid could not be expected, but methyl-thio- 
glycollic acid might result from the hydrobromate of dimethyl-thetine by loss 
of bromide of methyl— 
CH, CH, 
| 
Br—S—CH, = wy + CH,Br. 
| | 
CHO? GH. —00;H 
* Considerable pressure was observed on opening the tube. 
+ Herrz, “ Ann. der Chem. u. Pharm.” exxxvi. 214, and exlv. 49. 
+ Thioglycollic acid may be compared both with glycocoll and diglycol-amidie acid, as in each of 
these substances the nitrogen is partly saturated with hydrogen and partly with glycolyl The pro- 
perties of thioglycollic acid, however, point to a stronger resemblance to diglycol-amidic acid than to 
glycocoll. 

