960 Wisconsin Academy of Sciences, Arts, and Letters. 
For a more detailed discussion of this subject, see under in¬ 
dividual oleoresins. 
Acid Number: 
Kremel in 1887 determined the acid numbers of the oleo¬ 
resins of aspidium and cubeb. Inasmuch, however, as he made 
but one determination in each case, no conclusions can be drawn 
from his work. Similar determinations made in this laboratory 
on all of the official oleoresins show that this property varies 
greatly depending on the particular individual under considera¬ 
tion. Furthermore, that no general statement can be made as 
to its value in fixing the standards of these preparations, but 
that it is of importance when considered in connection with 
individual cases as will be brought out later. 
For the manner in which this constant was determined in 
the laboratory, see the United States Pharmacopoeia, ninth re¬ 
vision, (1916), p. 591. 
Saponification Value: 
The saponification values of the official oleoresins, as deter¬ 
mined in this laboratory and elsewhere, 1 ) indicate that this 
property may be an important factor in fixing standards for 
these preparations. The results obtained by Parry, Harrison 
and Self, and others show that in the case of the oleoresin of 
aspidium, the saponification value varies directly as the filicin 
content, and is, therefore, useful as a check on the determina¬ 
tion of the latter. Considered in connection with such of these 
preparations as contain easily oxidizable substances, an abnor¬ 
mally high saponification value is very likely caused by an in¬ 
crease in the acid content due to the action of the oxygen of the 
air, and is thus an indication of an old product 2 ) or of improper 
care in storing. As an example, the oleoresin of lupulin may 
be cited. In this case, a high saponification value signifies an 
old preparation or one that has been prepared from deteriorated 
drug. 3 ) These factors, together with the influence of the solvent 
employed and the method of preparation on this property, will 
1 Saponification values have only been determined in the past in the case 
of the oleoresin of aspidium and in one instance in the case of the oleoresin 
of cubeb. 
2 See oleoresin of aspidium. 
3 See oleoresin of lupulin. 
