160 REPORT— 1900. 



fore, that the strong ammonia used (35 per cent. NH3) contains approxi- 

 mately '000 14 per cent, pyridine. 



Although pyridine is thus shown to be the principal cause of the ab- 

 sorption, minute traces of its higher homologues and of volatile bases of 

 other series are also probably present, as the slight differences between 

 the spectrum of ordinary ammonia and that of pure pyridine appear to 

 indicate. 



Methylamine Hydrochloride. 



Methylamine was investigated by Hartley and Huntington in cells 

 50 mm. thick. 1 



An aqueous solution of methylamine was converted into hydrochloride 

 and the salt purified by repeated recrystallisation. A layer ]50 mm. 

 thick of a solution containing 25 grams of methylamine as hydrochloride 

 in 100 c.c. distilled water showed practically no absorption. There was 

 a slight weakening of the spectrum towards the ultra-violet end, and 

 one or two of the lines at the extreme end of the ultra-violet were 

 cut off. 



Hydroxylamine Hydrochloride. 



The hydroxylamine hydrochloride examined was subjected to re- 

 peated recrystallisation. It gave no precipitate with platinic chloride 

 in presence of alcohol and ether, and it was therefore assumed to con- 

 tain no ammonium chloride. The salt is highly diactinic and shows no trace 

 of selective absorption. A layer 150 mm, thick of the solution containing 

 5 grams of hydroxylamine in 100 c.c. water gives a continuous spectrum 

 to ^ l\ 4125 (A. 242*). A layer of the same thickness containing 2' 5 grams 

 in 100 c.c. water transmits the whole spectrum with the exception of a 

 few of the lines at the extreme end of the ultra-violet. 



Acetaldoxime,CR.,-CYi.-:^-Oll. 



Acetaldoxime was prepared in the usual manner by the action of alde- 

 hyde ammonia on hydroxylamine hydrochloride, and afterwards purified 

 by fractional distillation until the boiling point was constant : it boiled at 

 114-115°. In solution this compound shows no selective absorption, but 

 very considerable general absorption. A layer 150 mm. thick of a solu- 

 tion containing 125 grams of acetaldoxime in 100 c.c. water absorbs all 

 lines beyond '/A. 3323 (\ 3009). A layer 25 mm. thick of a solution con- 

 taining 1 milligram-mol. in 20 c.c. water gives a continuous spectrum to 

 '/A 3952 (\ 2530), and a layer 1 mm. thick of the same solution shows a 

 continuous spectrum to '/'^ 4417 (A. 2264). 



Acetoxime, (CII^)P:^-0YL. 



Acetoxime was prepared in the usual manner by the action of hydrox- 

 ylamine hydrochloride on acetone, and was purified by repeated recrys- 

 tallisation from water : it melted at SO-GO"^. 



Like acetaldoxime, acetoxime shows no selective absorption, but 

 general absorption, which is slightly greater than in the case of the 

 former substance, as was to be anticipated from the presence of an 

 additional methyl group. A layer 25 mm. thick of a solution of ace- 



' PMl Trans., 1879, Part I., 267. 



