186 ON THE IMPURITY OP SOME DRUGS. 
therefore, that the specimens may vary slightly ; sulphate of 
lead is a probable ingredient, in minute quantities • but I 
very much doubt if the manufacturer of this article is ho- 
nest enough to supply his customers with even a trace of 
zinc. It is not a little remarkable that this adulterated ar- 
ticle should have for so long a period been infesting every 
drug-shop, to the utter exclusion, apparently, of the genuine 
article in England and Scotland, without any complaint 
from those who purchased it. Does this fact not prove that 
as calamine is used in the form of ointment, it is the lard 
which is the efficient application I Mr. George Schweitzer, 
of Brighton, first published an account of the impure milk 
of sulphur in the British Annals of Medicine, in 1837, 
vol. i., p. 618, and showed that the sulphate of lime was 
introduced by substituting sulphuric acid for muriatic acid 
in the precipitation of the sulphur from its base. I may 
mention that this adulteration is easily detected by the mi- 
croscope, the crystals of sulphate of lime being very appa- 
rent. It is not easy to discover any other method of ex- 
cluding such adulterated articles from commerce, unless by 
the acquisition of a scientific knowledge of chemistry by 
the druggists of this country. 
London Lancet. 
