Du Mez—Tfoe Galenical Oleoresins. 
959 
In the determinations of this nature made in the laboratory, 
a weighed amount of the oleoresin (about 2 grams) was heated 
in an electric oven at 100° C for 3 hours, cooled in a desiccator 
and weighed, the difference in the two weights being taken as 
the loss. 
A more detailed consideration of this subject will be found 
under the treatment of the individual oleoresins. 
Ash Content: 
The determination of the ash content of the oleoresins is 
of special value in identifying the solvents which have been used 
in their preparation. Such determinations, made in this 
laboratory, also by the firm of Dieterich 1 ) in Helfenberg, have 
shown that, while there is as a rule comparatively little dif¬ 
ference in the ash content of these preparations, when prepared 
with the same solvent, there is a marked variation in the case 
of each individual when different solvents are employed. The 
oleoresin of lupulin is an exception to this rule. It's ash con¬ 
tent varies to a considerable extent even when prepared with 
the same solvent. 
In addition to the above, the qualitative examination of the 
ash of commercial samples has revealed the fact that nearly all 
of them contain copper, due in most cases to the action of the 
free fatty acids on the utensils employed in their preparation. 
In some instances, the presence of the metal must be attributed 
to the addition of copper salts for the purpose of imparting 
the desired green color to preparations of inferior quality. See 
under the adulteration of the oleoresins of aspidium and cubeb, 
respectively. 
The ash content of the oleoresins examined in the laboratory 
was determined as directed by the last edition of the United 
States Pharmacopoeia under ^Determination of Ash or Non¬ 
volatile Matter,” p. 589. 
Copper, when present, was identified by the blue color of the 
solution formed when the ash was dissolved in a few drops of 
hydrochloric acid, diluted with water, and ammonium hy¬ 
droxide solution added. 
1 The firm of Dieterich has for a number of years determined the ash 
content of the oleoresins of aspidium and cubeb. A tabulation of the re¬ 
sults as obtained by this firm will be found under the separate treatment 
of these oleoresins. 
