Du Mez—The Galenical Oleoresins. 
961 
be considered in greater detail under the treatment of the in¬ 
dividual members. 
The manner in which this constant was determined in the 
laboratory is described on p. 590 of the United States Phar¬ 
macopoeia, ninth revision. 
Iodine value: 
The determination of the iodine value as an aid to the 
standardization of the oleoresins appears to have been first em¬ 
ployed by the firm of Dieterich in Helfenberg in 1904, however, 
only in the case of the oleoresin of aspidium. It has since re¬ 
ceived further practical application, in connection with the same 
preparation, by the English firm of Evans Sons, Lescher and 
Webb, while a number of similar determinations have been made 
by the author. The results 1 ) obtained with respect to this 
preparation show that the iodine value varies directly as the 
filicin content, and, therefore, serves as another check on the 
determination of the latter constituent. 
With respect to the other official oleoresins, it may be stated 
that, as a general rule, the iodine value is high in the case of 
those preparations which contain a large amount of unsaturated 
constituents of ether fatty or volatile oil. 2 ) Further than this, 
it may be influenced largely by the pature of the other consti¬ 
tuents of these preparations and will be considered in detail in 
connection with the treatment of each individual. 
For the method employed in the laboratory in the determina¬ 
tion of this constant, see the United States Pharmacopoeia, ninth 
revision, p. 590. 
Special Tests 
While the different official oleoresins can, as a rule, be identi¬ 
fied without difficulty, the use of various adulterants in their 
preparation, through ignorance in some cases, or with willful 
intent on the part of unscrupulous manufacturers, has made 
it necessary to guard against this practice by making use of 
certain qualitative and quantitative tests. As will be brought 
out later, such tests have been applied principally to the pre¬ 
parations official in foreign countries, namely: the oleoresins 
1 See under oleoresin of aspidium. * 
2 See under oleoresin of eufoeb. 
61—S. A. L. 
