268 
ADULTERATION OF SULPHATE OF QUININE. 
in ether, it appears that the ten grains of the salt to be examined 
may contain one grain of quinidine, and still a complete solution 
with ether and ammonia may follow ; but in this case the quinidine 
will shortly begin to crystallize in the layer of ether. The last 
trace of quinidine may be yet more definitively detected by employ- 
ing, instead of the ordinary ether, some ether previously saturated 
with quinidine, by which means all of the quinidine contained in 
the quinine must remain undissolved. It is particularly requisite 
in performing this last experiment to observe, after the shaking, 
whether all has dissolved, for owing to the great tendency of 
quinidine to crystallization, it may become again separated in a 
crystalline form, and be a source of error. 
If more than a tenth of quinidine or cinchonine be present, there 
will be found an insoluble precipitate at the limits of the two 
layers of fluids. If this be quinidine, it will be dissolved on the 
addition of proportionately more ether, while cinchonine will be 
unaffected. 
It is expressly to be remarked, that the necessity for testing 
sulphate of quinine in search of other fraudulent adulterations is 
not superceded by the above described process. 
We have particularly to determine upon the absence of inorganic 
substances, which may be effected by red heat on a platinum dish, 
or simply by solution in alcohol. Gypsum, chalk, magnesia, &c, 
will be left undissolved. Boracic acid will be dissolved by alcohol, 
but its green flame will indicate its presence in the alcoholic 
solution when ignited. 
The absence of organic substances, such as salicine, sugar, 
stearic-acid, &c, may be inferred from the formation of a colorless 
solution with pure concentrated cold sulphuric acid : it is as well 
to leave the sulphuric acid to act for some hours. 
The presence of sal-ammoniac may be detected by the addition 
of caustic potash to the suspected salt, when, if present, it will be 
known by the diffusion of the ammoniacal odor. — London Pharm. 
Jour. March, 1852. 
