1006 Wisconsin Academy of Sciences , Arts, and Letters. 
The application of these tests in the laboratory has shown 
that they are of practically no value as an indication of the 
quality of the oleoresin, as preparations very low in crude 
filicin content give comparatively heavy precipitates when 
treated as described above. Furthermore, they do not serve 
as a means of identification as oleoresins prepared from the 
rhizomes of certain other species of fern 1 behave in a similar 
manner when subjected to these conditions. 
Tests for Starch 
A test for the presence of starch has been included in those 
pharmacopoeias in which the oleoresin is directed to be pre¬ 
pared by the process of maceration, namely, the German and 
Japanese. In these instances, it serves as a means of distin¬ 
guishing between preparations which have been filtered as of¬ 
ficially directed and those which have been merely strained 
through cloth as is often the case. A similar test is also found 
in the pharmacopoeias of those countries (Hungary, Spain and 
Switzerland) in which this preparation is frequently made by 
maceration, although the official process is that of percolation. 
The test as officially recognized in the different countries is 
identical with that described in the German Pharmacopoeia. 
It is as follows: 
The oleoresin, when diluted by shaking with glycerin, should not 
show the presence of starch grains under the microscope. 
Experience in the application of this test to the preparations 
examined in the laboratory has shown that it is unsatisfac¬ 
tory when carried out as described above. The fault lies in 
the fact that the glycerin cannot be thoroughly mixed with 
the oleoresin by shaking. If mixing is effected by trituration 
in a mortar, the results are better, although there is consider¬ 
able danger in rupturing the starch grains by this procedure. 
In addition to the foregoing, special tests have been pro¬ 
posed for the detection of adulterants when present. They 
are as follows: 
1 See under “Drug used, its collection, preservation, etc.” 
