526 POISONS : THEIR EFFECTS AND DETECTION. [§ 69I. 
and in cold water ; this property is also useful to separate it from putres¬ 
cine, the mercury compound of which is soluble in cold water. The 
platinochloride, C 5 H 14 N 2 2HCl,PtCl 4 (Pt = 38-08 per cent.), crystallises in 
dirty red needles ; but, by repeated crystallisation, it may be obtained 
in clear chrome-yellow, short, octahedral prisms ; it is soluble with 
difficulty in hot water, insoluble in cold water. The salt decomposes 
at 235°-236°. 
The aurochloride—C 5 H 14 N 2 2HC12AuC 1 (Au = 61-5 per cent.), melt¬ 
ing-point 188°—crystallises partly in cubes and partly in needles, and 
is easily soluble in water. 
Other salts are the picrate, C 5 H 14 N 2 2C 6 H 2 (N0 2 ) 3 0H, melting-point 
221 ° with decomposition ; with difficulty soluble in cold, but dissolving 
in hot water, and insoluble in absolute alcohol. The dipicrolonate. 
C 5 H 14 N 2 2C 10 H 8 O 5 N 4 , melting-point 250°; soluble in 7575 parts cold 
water and 5952 cold alcohol. There are also a neutral oxalate, 
C 5 H 14 N 2 ,H 2 C 2 0 4 + 2H 2 0, melting-point 160°; and an acid oxalate, 
C 5 H 14 N 2 2H 2 C 2 0 4 + H 2 0, melting-point 143° with decomposition ; both 
these oxalates are insoluble in absolute alcohol. 
Cadaverine dibenzoyl—C 5 H 10 (NHCOC 6 H 5 ) 2 , melting-point 129°-130° 
—crystallises in needles and plates, soluble in alcohol and slightly 
soluble in ether, insoluble in water. 
It is not acted on by hot dilute acids or alkalies, and when dissolved 
in concentrated hydrochloric acid and alcohol it is, only after prolonged 
boiling, decomposed into benzoic acid and the free base. The benzoic 
acid, after getting rid of the alcohol by evaporation, can be removed by 
shaking up with ether ; then the hydrochloride can be decomposed by an 
alkali and the free base obtained, or the platinum salt of cadaverine may 
be formed by precipitation with platinum chloride. Should cadaverine 
and putrescine be in the same liquid, the dibenzoyl compounds may be 
separated as follows :—The crystalline precipitate is collected on a filter, 
washed with water until the filtrate runs clear, and then dissolved 
in warm alcohol; this solution is poured into twenty times its volume of 
ether and allowed to stand ; after a short time crystals form of the 
putrescine compound, which' are far less soluble in alcohol than those of 
cadaverine dibenzoyl; these crystals are filtered off and repeatedly 
crystallised from alcohol until the melting-point is about 175°-176°. 
The filtrate contains the cadaverine compound ; this latter is recovered 
by evaporating off the ether-alcohol. 
§ 691. Putrescine—Tetramethylenediamine, 
C 4 H 12 N 2 = NH 2 CH 2 CH 2 CH 2 CH 2 NH 2 . 
The free base is a clear liquid, with a semen-like odour, boiling-point 
135°. It is a common base in putrefying animal substances, and also 
occurs in the urine in cases of cystinuria. It can be obtained syntheti- 
