650 



of alkali produces a broad band from 2040 to 2300 (curve 2). Its 

 centre is at about the same place as the centre of the two bands, 

 Avhich show the picryhnethylamide derivates in presence ofallialies. 



In the previous publication (1. c.) we mentioned a remarkable 

 decomposition of the alkaline solution of picrylmethylnitramine. After 

 a day it gave the spectrum of potassium picrate, being hydrolysed in 

 this way : Pier. N Me NO, -» Pier. OH + Me NH NO,. 



An analogous decomposition takes place, though more slowly, with 

 the acetyl derivative and the two urethanes. In a few days the spec- 

 trum of their alkaline solutions is perfectly the same as that shown 

 by potassium picrate (curve 7). 



With picrylmethylnitrosamine this decomposition proceeds very 

 quickly, much more rapidly than with the nitramine. During the few 

 minutes required for the spectrographic examination its alkaline 

 solution is already partly decomposed. 



The anomalous absorption curve (4) is apparantly due to a super- 

 position of the spectrum of the potassium compound of the nitro- 

 samine with that of potassium picrate. Fiom the three bands shown 



by this curve at - 2000, 2400 and 2900 the latter is ujidoubtedly 



caused by the presence of potassium picrate, which gives a band at 

 about 2880. In the spectrum of the potassium compound of the nitro- 

 samine there may be expected two bands at about 2000 and 2350, 

 in analogy to the observations made with the other derivatives of 

 pier} Imethylamide. The former band is indeed present, whilst the 

 second band, likely with assistance of the flat band shown by 

 potassium picrate at 2500, is transferred to 2400. Two hours after its 

 preparation, the alkaline solution of the nitrosamine was again 

 examined ; it then showed the pure spectrum of potassium picrate 

 (curve 7). 



The i-esults of this investigation may be expressed as follows. 



The coloration of picrylmethylnitramine by alkali has the same 

 cause as the coloration of other derivatives of picrylmethylamide by 

 this reagent. 



For the nitramine, the acetyl-, carboxymethyl- and carboxyethyl- 

 derivatives, which altogether only have continuous absorption for 

 ultraviolet rays, show two bands at about 2000 and 2350 after addition 

 of alkali. Picrylphenylmethylamide has already of itself an absorption 

 band, which, however, by alkali is divided into two parts at 2070 

 and 2400. 



