DIAMINES. 
§§ 692, 693.] 
52 7 
cally by reducing ethylene cyanide by the action of sodium in absolute 
alcohol. 
The best method of separating putrescine is the benzoyl chloride 
method already given. 
Putrescine forms crystalline salts, of which the following are the 
most important :— 
Putrescine hydrochloride, C 4 H 12 N 2 2HC1, forms long colourless 
needles, insoluble in absolute alcohol, easily soluble in water. 
The platinochloride, C 4 H 12 N 2 2HCl.PtCl 4 (Pt=39-2 per cent.), is 
with difficulty soluble in cold water. When pure, the salt is in the 
form of six-sided plates. 
The aurochloride, C 4 H 12 N 2 2HC1.2AuCl 3 +2H 2 0 (Au=51*3 per cent.), 
is insoluble in cold water, in contradistinction to cadaverine aurochloride, 
which easily dissolves. 
The picrate, C 4 H 12 N 2 2C 6 H 2 (N0 2 ) 3 0H, is a salt of difficult solubility. 
It crystallises in yellow plates. It browns at 230°, and melts with 
evolution of gas at 250°. 
The dipicrolonate, C 4 H 12 N 2 2C 10 H 8 O 5 N 4 , is only soluble in 13,157 
parts water, and 17,857 cold alcohol; it decomposes at 263°. 
Dibenzoylputrescine, C 4 H 8 (NHCOC 6 H 5 ) 2 , forms silky plates or long 
needles, melting-point 175°-176°. By boiling it for twelve hours with 
alcohol and strong hydrochloric acid the compound may be broken up 
into hydrochloride of putrescine and free benzoic acid. As stated 
before, it is less soluble in alcohol than the corresponding compound 
of cadaverine. 
Putrescine is not poisonous. On the other hand, by repeated treat¬ 
ment with methyl iodide, it takes up four methyl radicals, and the 
tetramethvl compound, C 4 H 8 (CH 3 ) 4 N 2 , produces symptoms similar to 
those of muscarine poisoning. 
NH, 1 
§ 692. Metaphenylenediamine, C 6 H 4 <^ , is a crystalline sub- 
NH 2 * 
stance, melting-point 63°, boiling-point 276°-277°. The crystals are 
easily soluble in alcohol or ether, with difficulty in water. The least 
trace of nitrous acid strikes a yellow colour from the formation of 
triamidobenzol. 
NH 2 i 
§ 693. Paraphenylenediamine, C 6 H 4 / , is in the form of 
NH 2 4 
tabular crystals, melting-point 140°, boiling-point 267°. If this substance 
is oxidised with ferric chloride or manganese binoxide and sulphuric acid, 
chinone is produced ; if treated with SH 2 and ferric chloride, a violet 
sulphur-holding colouring matter, allied to methylene blue, is formed ; 
these reactions are tests for the presence of the para-compound. 
