608 DR E. A. LETTS ON THE ACTION OF 
boiled with caustic potash. Their solution was not precipitated by nitrate of 
silver, but after they had been fused with caustic potash and the mass dissolved 
and acidulated, bromide of silver was precipitated in large quantity on adding 
the nitrate. Unfortunately the amount of oily liquid at my disposal was small, 
as it was not produced in large quantity, and this is the more to be regretted 
because all the attempts I have subsequently made to obtain the same body 
have been unsuccessful. 
I have repeated the experiment of boiling the crude thetine hydrobromate 
with methylated spirit several times, also with absolute alcohol, and each time 
after the greater part of the thetine had crystallised out and water was added 
to the mother liquors heavy oily liquids were obtained which possessed a 
pungent and irritating odour. Each time, however, they appeared to have a 
different composition. They were all dissolved by ammonia more or less 
rapidly, but the resulting products differed on each occasion ; sometimes they 
were only moderately soluble in water, sometimes they were so deliquescent 
that they could not be recrystallised. Once bromide of ammonium was obtained. 
Owing to the small quantities of the oily liquids obtained, and consequently also 
of the products of the action of ammonia on the latter, I have been able to 
make only a few analyses of the latter. Once, however, a sufficiently pure product | 
was obtained, which after recrystallisation from water yielded the following — . 
numbers :— 
Te Il. Ill. 
Carbon, : ; 5 32°97 30°12 34°26 
Hydrogen, . : : 5°77 6:14 611 
The mother liquors on concentration yielded more of the crystalline sub- 
stance, which, when recrystallised, gave— 
Carbon, : ‘ : 34°81 Onan 
Hydrogen, . - 5 69 6:9 
A comparison of these results indicate that the substance was not pure. 
I should remark that attempts made to fractionate the oily liquids gave no 
satisfactory result, the temperature gradually rising. 
The fact that the oily liquids possessed a pungent irritating odour, and that 
they did not occur in any considerable quantity when the thetine compound 
was boiled for a short time with alcohol, led me to think that they might con- — 
sist of mixtures of monobromacetic and dibromacetic ether. The former would 
result from the action of the alcohol on monobromacetic acid, which had not 
combined with sulphide of methyl (and, as a fact, I have observed that in the 
preparation of all the thetine hydrobromates, some of the hydrocarbon sulphide 
remains unacted on,—the quantity so remaining increasing with each higher. 
homologue). The latter, the dibromacetic ether, would be formed by the 

