980 Wisconsin Academy of Sciences, Arts, and Letters. 
the formation of a deposit, namely: that the ethereal tincture 
be kept on hand and that the oleoresin be prepared therefrom 
just previous to dispensing. 
Yield 
The yield of oleoresin, when ether is the solvent employed 
in extracting the drug, is commonly stated to be 10 to 15 per 
cent, in the various dispensatories and American text-books on 
pharmacy. As a matter of fact, the amount of oleoresin actually 
obtained is about 7 to 10 per cent. (See the tables which fol¬ 
low.) When petroleum ether or benzene is used, the yield is 
slightly lower, as a rule, whereas, it is much higher (about 18 
per cent.) when acetone is employed. These statements refer 
to the yield as found for the air dried drug. When the latter 
is dried at a temperature of 100 to 110°C, the percentage of 
oleoresin obtained will naturally be somewhat higher as is shown 
in the table immediately following. 
