Du Mez—The Galenical Oleoresins. 
1007 
Tests for the Presence of the Oleoresin of Dryopteris Spinulosa. 
Hausmann found that the male fern of commerce frequently 
contained large quantities of the rhizomes of Dryopteris spinu¬ 
losa Kunze. He therefore devised a test for the detection of the 
use of the latter in the preparation of the oleoresin. It is based 
on the fact that the rhizomes of Dryopteris spinulosa Kunze 
contain aspidin, whereas those of the official species, Dryopteris 
Filixmas Schott do not. 
Hausmann’s Method (1899): Dissolve a small amount of crude filicin 1 
in as small a quantity of absolute ether as possible and set the solution 
aside in a desiccator. If aspidin is present, the thick solution will form 
a crystalline brine in a few hours, when the needle-like crystals of the 
former can easily be identified under the microscope. If aspidin is not 
present, the solution undergoes no change even on long standing except 
to deposit a granular substance. 
Tests for the Presence of Castor Oil 
The tests for the presence of castor oil are based on the 
solubility of the oleoresin in various solvents and are discussed 
under the heading, ‘ ‘ Solubility.’ ’ 
Tests for the Presence of Salts of Copper 
The tests for the presence of salts of copper involve an ex¬ 
amination of the ash of the oleoresin and are discussed under 
the general treatment of the subject, 4 ‘Ash content.’’ 
Special Quantitative Tests. 
A great deal of work has been done with reference to the 
evaluation of this preparation, and as a result, a number of 
methods for the quantitative estimation of the constituents of 
therapeutic importance has been devised. The chemical meth¬ 
ods may be conveniently divided into two groups, the one includ¬ 
ing those methods which have for their object the quantitative 
determination of the filix acid; and the other comprising the 
methods in which the quantity of the total constituents of an 
acid character is determined. 
1 See under “Special quantitative methods”. 
