THE AMINES. 
§ 678 .] 
519 
instance, methylamine NH 2 CH 3 is a primary or amide base, because 
only one of the three atoms of H in NH 3 has been replaced by methyl ; 
similarly, dimethylamine is a secondary or imid base, and trimethyl- 
amine is a tertiary or nitrile base. 
The quaternary bases are derived from the hypothetical ammonium 
hydroxide NH 4 OH, as, for example, tetraethyl ammonium hydroxide 
(C 2 H 5 ) 4 N,OH. 
The diamines are derived from two molecules of NH, and therefore 
contain, instead of one molecule of nitrogen, two molecules of nitrogen ; 
in two molecules of ammonia there are six atoms of hydrogen, two, 
four, or six of which may be replaced by alkyls ; as, for example, 
/C 2 h 4X 
N^- HH —N 
\hh/ 
Ethylenediamine. 
c 2 H 4 , 
N x C 2 H 4 ^N 
\ HH/ 
Diethylenediamine. 
/C 2 h 4X 
NfC 2 H 4 -)N 
x c 2 h/ 
Triethylenediamine. 
The monamines are similar to ammonia in their reactions ; some of 
them are stronger bases ; for instance, ethylamine expels ammonia from 
•its salts. The first members of the series are combustible gases of 
pungent odour, and easily soluble in water ; the higher homologues are 
fluids ; and the still higher members solids. 
The hydrochlorides are soluble in absolute alcohol, while chloride of 
ammonium is insoluble ; this property is taken advantage of for separat¬ 
ing amines from ammonia. The amines form double salts with platinic 
chloride ; this is also utilised for recognition, for the purpose of separa¬ 
tion, and for purification ; for instance, ammonium-platinum-chloride on 
ignition yields 43-99 per cent, of platinum, and methylamine-platinum- 
chloride yields 47*4 of platinum. It is comparatively easy to ascertain 
whether an amine is primary, secondary, or tertiary. 
The primary and secondary amines react with nitrous acid, but not 
the tertiary ; the primary amines, for instance, are converted into 
alcohols, and there is an evolution of nitrogen gas ; thus methylamine is 
decomposed into methyl alcohol, nitrogen, and water. 
CH 3 NH 2 + (OH)NO = CH 3 ( OH) + N 2 + H 2 0. 
The secondary amines, treated in the same way, evolve no nitrogen, 
but are converted into nitrosamines ; thus dimethylamine, when treated 
with nitrous acid, yields nitrosodimethylamine, 
(CH 3 ) 2 NH+ (OH)NO=(CH 3 ) 2 (NO)N+H 2 0 ; 
and the nitrosamines respond to the test known as Lieberman’s nitroso- 
reaction, which is thus performed :—The substance is dissolved in phenol 
and a few drops of concentrated sulphuric acid added. The yellow 
colour at first produced changes into blue by adding to the acid liquid 
a solution of potash. 
The primary amines, and the primary amines alone, treated with 
