952 Wisconsin Academy of Sciences , Arts , and Letters. 
Yield 
The yield of oleoresin is a variable quantity depending, first 
of all, upon the oleoresin content of the particular drug from 
which it is prepared. Thus, the oleoresin content of ginger 
is only about one-half that of the aspidium and one-fourth that 
of cubeb. Not, only, however, does the oleoresin content vary 
with the different drugs, but the drug, when of the same genus 
and species, may show a variation due to a number of in¬ 
fluences, such as the climate in which grown, time of harvest¬ 
ing, conditions under which stored, et cetera. As an illustra¬ 
tion of these influences, aspidium may be taken. The maxi¬ 
mum yield of oleoresin, in this case, is obtained from the freshly 
dried Russian rhizomes collected in the month of September. 1 ) 
Or, the case of ginger may be cited. In this instance, the 
African rhizomes harvested at maturity (usually in Feb¬ 
ruary) 1 ) give the largest amount of oleoresin. This character¬ 
istic will be taken up in detail under the treatment of the 
individual oleoresins. The other important factors in deter¬ 
mining the amount of oleoresin obtained, in general, are two 
in number, viz: the solvent employed in extracting the drug, 
and the method employed in operating with the same. Both 
of these factors have been dealt with in a general way under 
the two preceding headings. They will also be discussed more 
fully in connection with the individual preparations. 
Chemistry 
The Chemistry of the oleoresins per se has apparently re¬ 
ceived but little attention, except in the case of the 
oleoresin of aspidum. The latter has been the subject 
of numerous investigations and its chemistry is now under¬ 
stood fairly well. Some work has also been done toward de¬ 
termining the composition of the oleoresins of cubeb and 
lupulin, but our present knowledge of the chemistry of these 
preparations is still very indefinite. 
A very considerable amount of work has been done toward 
clearing up the chemistry of the drugs from which the oleo¬ 
resins are prepared, and it is from this source that we are 
1 See tables of yield under the oleoresins of aspidium and ginger, re¬ 
spectively. 
