Observations on a new variety of Peruvian Bark, Sc. 55 
in mint water. This, he continues, is obviously injudicious, since 
tartaric acid decomposes the sulphate and occasions an insoluble tar- 
trate, which is precipitated. With deference to Dr. Paris, I would 
beg leave to differ, on the following grounds. The cream of tartar 
is objectionable, merely from the circumstance that the active part 
compound may be obtained in a more direct and speedy pro- 
cess by the tartaric acid. The combination of cream of tartar and 
sulphate of quinine, in the above prescription, does produce decom- 
position, as Dr. Paris has observed, but the virtue of the medicine 
is not in the least affected by it, and the precipitate, instead of being 
an insoluble tartrate of quinine, as he observes, is sulphate of po- 
tassa ; tartrate of quinine is a very soluble salt and is held in solu- 
tion, while the water becomes slightly turbid, by. the a of 
sulphate of potassa, which however, from its extremely minute 
vision, is speedily taken up by the water, when you have a transpa- 
rent solution of tartrate of quinine and sulphate of potassa, and as 
the latter answers neither a good nor a bad purpose, it of course can 
very conveniently be dispensed with, and therefore, as before stated, 
the tartaric acid should be preferred, as having a more direct and 
speedy action. 
The high price which the sulphate of quinine has always com- 
manded, and the increasing demand which its reputation has con- 
stantly kept up, has been an inducement to fraud ; and it is much to 
be regretted that this valuable article of our materia medica, like 
others of an expensive kind, has been mixed with foreign substances 
of inert character, for the base consideration of reducing the cost 
and enhancing the profit on its sale, and all this at the expense of the 
of the suffering patient, to the disappointment of the practi- 
tioner, and not unfrequently to the injury of the reputation of the 
genuine medicine. It is of high importance therefore to be acquaint- 
ed with the most efficient means of testing its character, where we 
have any doubt of its purity. The following: are the distinctive char- 
acters and properties of the sulphate of quinine, and the most simple 
and “aera method of discovering fraud or adulteration in its com- 
Position 
1. ae sulphate of quinine must be soluble, at a moderate heat, in 
rectified alcohol; if it contains sulphate of lime, soda, potassa, or any 
Sr ae ee 
* See observations, communicated by Dr. Faust, on the adulteration of quinine, 
hark, &e. Vol. XVIII, pp. 81, 84, of this Journal.—Ed. 
