188 
ON AMORPHOUS QUININE. 
prevent their use. In many of these cases, indeed, having 
no direct or ready way of testing them, we rely solely upon 
the honorable character* of the merchant and dealer; but 
we have a completely satisfactory test for the purity of 
amorphous quinine. Few medicinal agents afford so ready 
a means of distinguishing them, and detecting admixtures, 
as the organic alkaloids: but if these tests are not employ- 
ed, it is as easy to be deceived in purchasing crystalline sul- 
phate of quinine, as the amorphous. 
Amorphous quinine is completely soluble in dilute sul- 
phuric acid, and in alcohol, as I have said above ; it is also 
completely soluble in a solution of sulphate of copper, with 
separation of oxide of copper. And if its solution in a 
dilute acid yields, upon precipitation by means of ammonia, 
exactly the same amount of precipitate as the weight of the 
substance originally dissolved in the acid, there can be no 
doubt remaining as to the perfect purity of the sample under 
examination. 
It only remains for me to observe, that no dependence 
should be placed upon the ordinary quiniodine of commerce. 
As I have already stated, some samples which I have seen, 
dissolve incompletely in water, forming a dark-brown 
muddy fluid ; these have been probably produced by simply 
evaporating the mother-liquors of sulphate of quinine to 
dryness They are, therefore, uncertain mixtures of various 
substances with sulphate of amorphous quinine, with or 
without excess of acid, so that in purchasing such speci- 
mens, the buyer is paying the price of an organic alkaloid 
for sulphuric acid, &c. The pure amorphous quinine 
should be separated, and it would then form a most valua- 
ble remedial agent; but the prescriber must be assured of 
its purity, and the test I have given will suffice for this pur- 
pose. — Chemist. 
