35$ POISONS : THETR EFFECTS AND DETECTION. [§ 427 . 
permanganates ; all of them show slight differences in crystalline form. 
On the other hand, B eucaine, stovaine, novococaine, holocaine, and 
nirvane do not form crystalline permanganates. A good colour test 
for cocaine is sulphuric acid containing 2 per cent, formaldehyde. 
On heating cocaine with this mixture a wine-red colour is produced. 1 
Bromine water added to solutions of cocaine, scopolamine, stovaine, 
and novococaine gives a yellow precipitate, dissolving on heating. B eu¬ 
caine gives a precipitate which dissolves on warming, but on boiling 
reappears. Nirvane gives a yellow precipitate on heating the solution, 
and the latter acquires aredcolour. Holocaine yields a yellow precipitate 
with bromine water ; when the mixture is boiled the precipitate dissolves 
and a pinkish-white opalescence is produced in the liquid. A micro-test 
very characteristic of cocaine is a crystalline precipitate produced by 
trinitro-resorcin. 2 Fairlv concentrated solutions of cocaine show im- 
# 
mediate precipitation ; 1 part in 500 takes about an hour, and 1 in 2000 
about twenty-four hours ; but in all cases the precipitate is in the form 
of small yellow spherules, consisting of rosettes of fine crystals. 
The B.P. tests for cocaine hydrochloride are as follows :— 
“ When moistened with nitric acid, the mixture evaporated to dryness, 
and 1 millilitre (1 c.c.) of alcoholic solution of KOH added, a characteristic 
odour is evolved, recalling peppermint. The addition of 3 drops of 
K permanganate to a solution of 0*1 gramme of the salt in 5 millilitres 
(5 c.c.) of water to which 5 drops of diluted sulphuric acid have been 
added, gives a violet colour which, if dust is excluded, does not fade 
within half an hour (absence of cinnamyl-cocaine and certain other 
coca alkaloids). If 0-1 grm. is dissolved in 100 millilitres (100 c.c.) in 
a glass beaker, 0*25 millilitre (0-25 c.c.) of ammonia stirred in, and the 
mixture set aside for fifteen minutes, the sides of the beaker being occasion¬ 
ally and not too vigorously rubbed with a glass rod, a crystalline deposit 
separates, leaving the supernatant liquid clear (limit of amorphous 
alkaloid). 0-05 grm. dissolves in 1 millilitre (1 c.c.) of cold sulphuric 
acid or cold nitric acid without coloration ; but with hot sulphuric acid 
the salt chars, evolving an agreeable odour and yielding a sublimate of 
benzoic acid. Loses not more than 1 per cent, of its weight when dried 
at 100°. No appreciable ash.” 
Cocaine may be estimated in fairly strong pure solutions (1 per cent.) 
by adding a N/10 iodine until the iodine is in excess ; the hydriodide 
periodide is filtered off and the excess of iodine in the filtrate determined 
by N/10 sodium thiosulphate. The iodine compound formed is 
c 17 h 21 o 4 ,n,hii 2 .3 
§ 427. Symptoms. —A large number of accidents occur each year 
1 F. Pisani, Rend. Soc. Ital., 1914. 
2 Rosenthaler and Corner, Zeit. f. anal. Chemie, 1910. 
3 W. Garsed and J. N. Collie, Jour. Chem. Soc., Ixxix., 1901. 
