50 
ON QUINOIDINE. 
This precipitates a dark resinous mass, while the supernatant 
liquid is but faintly coloured ; it is separated from the pre- 
cipitate, and quickly precipitated with ammonia. The 
precipitate is then well washed and dried, and exhausted 
with alcohol as long as this removes anything ; the united 
extracts are again mixed with half the former amount of pro- 
tochloride of tin, again quickly precipitated with ammonia, 
and the well-washed and dried precipitate exhausted with 
alcohol, when an almost colourless solution of pure quinine 
is obtained, which, carefully saturated with dilute sulphuric 
acid, affords on evaporation crystals of sulphate of quinine. 
In the liquid filtered from the precipitate of protoxide of 
tin and quinine, as well as in the wash-water, cinchonine 
is contained, if ordinary quinoidine has been employed 
which has not been previously purified by precipitation 
with an alkali. These liquids, containing cinchonine, are 
precipitated with tincture of galls to obtain the cinchonine 
in the usual manner. 
The precipitated resinous substance still retains some 
quinine, to obtain which it is dissolved in alcohol, again 
mixed with a strong solution of protochloride of tin, and then 
further treated in the above-mentioned manner. The resin- 
ous substance so obtained is of an alkaline nature, of a 
bitter taste, and possesses the peculiar odour of quinoidine ; 
it would probably yield more quinine on further treatment. 
The author obtained by this process from two different 
samples of quinoidine, in one case 43 per cent, quinine, 9 
per cent, cinchonine, and 28 per cent, resin ; and in the 
second 40 per cent, quinine, 10 per cent, cinchonine, and 30 
per cent, resin ; the water amounted to 20 per cent. On 
precipitating 100 parts of commercial quinoidine in solution 
with an alkali, the precipitate obtained weighed 69 grs.— 
Chem Gaz. from Mittheilungen des Schweizer, 
