538 I'he Philippine Journal of Science wu 



distinguishing between an extract recently prepared from fresh 

 green rhizomes and that prepared from old rhizomes or in de- 

 tecting a deteriorated or adulterated product. Viewed from this 

 standpoint the following conclusions can be drawn. 



The color of the extract when prepared from fresh rhizomes 

 is yellowish green; a brownish shade indicates the use of old 

 rhizomes ; deep green means the addition of chlorophyll or other 

 foreign coloring material, such as a salt of copper. The use of 

 old rhizomes receives further confirmation in a low index of 

 refraction (the refractive index is also lowered by the addition 

 of castor oil) and in the dark color of the ethereal solution of 

 the crude filicin obtained in the filicin assay. The presence of 

 a copper salt can best be confirmed by an examination of the 

 ash, applying the usual tests for copper. The addition of 

 chlorophyll is difficult to detect chemically owing to its presence 

 as a natural constituent of the extract. However, the amount 

 which must be added to obscure the brown color imparted by 

 old rhizomes is so great that it can be easily detected with the 

 naked eye in the original sample and in the solubility tests. 



The addition of castor oil to the extract produces a con- 

 siderable change in all of its properties. It is especially In- 

 dicated in the low specific gravity, index of refraction, and 

 iodine and saponification values. Its presence can be most easily 

 confirmed by the solubility tests. 



The presence of aspidin can readily be determined by Haus- 

 mann's method which serves as a practical means of detecting 

 the use of Aspidium spinulosiim Sw. in the preparation of the 

 extract. 



The use of acetone as directed in the United States Phar- 

 macopoeia yields a product which separates in two layers upon 

 standing — an upper oily layer and a lower layer darker in color 

 and thicker in consistency than that above. This in itself serves 

 as a ready means of detecting its use, which is further con- 

 firmed by the solubility tests and the high ash content. 



The iodine and saponification values vary in the same direc- 

 tion as the filicin content, and, therefore, might be used to 

 displace the rather long and expensive method of the present 

 filicin assay. Especially is this true in the case of the saponi- 

 fication value, which requires but 1 gram of the extract and 

 less than an hour to complete. 



