Du Mez—The Galenical Oleoresins. 
955 
Solubility: 
The solubility of the different oleoresins naturally depends 
to a large extent on the solvent which was employed in their 
preparation. It does not, however, follow from this statement 
that, because an oleoresin was prepared with ether, it will al¬ 
ways be completely soluble in the same. Some of these pre¬ 
parations on standing undergo chemical changes with a result¬ 
ing change in solubility. For example, the oleoresin of aspi- 
dium forms a deposit on ageing, and the deposited material is 
practically insoluble in ether. As a rule, the oleoresins, when 
prepared with ether, form clear or slightly cloudy solutions 
with absolute alcohol, acetone and chloroform, whereas, they 
are only partially soluble in petroleum ether and carbon tetra¬ 
chloride. 
In the case of certain members of this class of preparations, 
this property has been of considerable value in detecting adul¬ 
terations or in the identification of the solvent which was em¬ 
ployed in their manufacture. For specific instances of the 
application in this connection, see under the oleoresins of aspi- 
dium and ginger. 
Specific gravity: 
The value of determining the specific gravity as an aid to 
standardizing the oleoresins appears to have been first noted by 
Procter. In 1866, he published data showing how this constant, 
in the case of the oleoresin of cubeb, varied with the solvent 
employed in its preparation, and further pointed out that a low 
specific gravity observed in the commercial product was, in one 
instance at least, an indication of the incomplete removal of 
the solvent, ether. Procter's observations were as follows: 
Table 7. — The specific gravity of the oleoresin of cubeb. 
Drug 
Solvent 
Specific gravity 
Remarks 
Cubeb. 
Alcohol. 
at 76° F. 
0,9850 
0.9675 
0 9325 
0.9000 
Prepared by Procter. 
(• 4 « .6 
Commercial sample containing ether. 
Ether.. 
Benzin ...... 
Ether... 
This work, however, appears to have received but little atten¬ 
tion as there is no further mention of the determination of this 
