THE 
AMERICAN JOURNAL OF PHARMACY. 
C T B ER, 1852. 
OBSERVATIONS ON THE VOLATILITY AND SOLUBILITY OF CAN- 
THARIDIN IN VIEW OF THE MOST ELIGIBLE PHARMACEUTICAL 
TREATMENT OF SPANISH FLIES. 
By William Procter, Jr. 
Cantharides have been used in Pharmacy since the days of 
Hippocrates. It was not till 1810, however, that the principle 
giving them activity was isolated by Robiquet (Annal. de Chimie 
lxxvi. 302,) and subsequently named Cantharidin by Dr. Thomas 
Thompson. Since then various experimenters have been en- 
gaged in the chemical investigation of these flies, and in the more 
recent treatises they are stated to consist of cantharidin, yellow 
fixed oil, green fixed oil, a yellow viscous substance, a black 
matter, ozmazome, uric acid, acetic acid, phosphoric acid, and the 
phosphate of lime and magnesia. It is proverbial among apothe- 
caries and physicians, that the pharmaceutical preparations de- 
signed to produce vesication, vary very much in their cower as 
prepared by different individuals, and from different samples of 
cantharides by the same recipes. Is this variableness of power due 
to the inequality of strength of the commercial drug ? or, are we 
to attribute it to the treatment employed by the apothecary ? The 
real importance of these queries demands an answer. To pro- 
ceed properly, the investigator should examine cantharidin in a 
pure state, ascertain how far the statements of writers are cor- 
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