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acyclic compounds from which the imide is derived, such as imino- 
diacetonitrile, iminodiacetic acid, its ester and imide. This at the 
same time also furnishes a contribution to our knowledge of the 
nitration of acyclic imino compounds from which it is again evident 
that the nitration of one NH-group placed between two CH,-groups 
(residues of saturated hydrocarbons) depends also on other consti- 
tuents attached to these: hydrocarbon residues. 
The results obtained are as follows : 
Iminodiacetonitrile HN(CH,CN), yields with ordinary nitrie acid a 
nitrate in beautiful glittering needles which melt at 1838—140° with 
decomposition. The formula was determined by analysis and titration 
of the nitric acid. It is readily soluble in cold water, soluble in hot 
methyl alcohol, ethyl alcohol and benzene. On slowly cooling a hot 
alcoholic solution it yields very beautiful crystals. If this nitrate is 
dissolved in absolute nitric acid (which is accompanied by a slight 
evolution of heat) and the acid is allowed to evaporate in vacuo 
over lime, the residue when triturated with absolute alcohol gives 
a erystal-paste which, after being dried and recrystallised from dry 
benzene, forms splendid snow-white needles melting at 100—101°. 
Their analysis points to the nitro-derivate NO,N(CH,CN), netro-imi- 
nodiacetonitrile. It gives the reaction of the nitramines with zine and 
an acetic acid solution of e-naphtylamine. On warming with water 
decomposition sets in. 
Iminodiacetic acid HN(CH,CO,H), gives a nitrate already described 
in 1865 by Heintz. When this nitrate is dissolved in absolute nitric 
acid and evaporated in vacuo over lime it is recovered unchanged. 
It is insoluble in ether, benzene and acetic ether. If, however, the nitric 
acid solution is heated to boiling a nitroderivative NO,N(CH,CO,H), 
nitroiminodiacetic acid is formed, which is left behind after evaporation 
of the nitric acid in vacuo over lime. It is soluble in methyl and ethyl 
alcohol in acetone and acetic ether, also in cold water. Crystallised 
from acetic ether it forms broad, flat needles mutually joined like a 
fan. Its melting, or rather decomposition point appears to lie at 
about 153°. Its aqueous solution is strongly acid and gives the above 
nitramine reaction. A neutral potassium salt was prepared which 
readily erystallises on addition of absolute alcohol to the watery solution; 
it is decomposed at about 195° with explosion. The acid potassium 
salt which is not easily soluble in alcohol and yields beautiful crystals 
was also prepared. From the ethyl ester of iminodiacetic acid described 
by Mr. Jonkers there was also prepared a nitrate, which is very little 
soluble in alcohol and erystallises in silky needles, which melt at 
