530 ^^6 Philippine Journal of Science ms 



states that the acid decomposes upon the aging of the extract 

 forming "filix acid" and "filixnigrine." In either case, it will 

 be noticed that the investigators have found a deterioration of 

 the extract upon standing, a fact which is corroborated by nu- 

 merous others. The only fact which has been definitely estab- 

 lished is that the extract when freshly prepared is homogeneous, 

 but upon aging it deposits filix acid among other substances and 

 becomes weaker in its action as a taeniafuge. This behavior of 

 the extract has been so universally observed that the various 

 pharmacopoeias give specific directions for the mixing of the 

 deposit with the liquid portion before dispensing. Viewed in 

 the light of the observations of Poulsson or Kraft, these direc- 

 tions are founded upon error and are superfluous. However, 

 Greenawalt,*^ Reuter,** and others contend that the deposit is 

 active. Here again, we are confronted with the uncertainty of 

 the exact nature of the process of deterioration and the futility 

 of attempting to estimate the therapeutic value of the extract by 

 a determination of the crude filicin or filix-acid content. 



In order to establish more definitely the physical and chemical 

 properties of the genuine extract prepared from the green rhi- 

 zomes, in contrast to those of the deteriorated or adulterated 

 product, the following constants of the genuine and commercial 

 samples have been determined and tabulated. 



METHODS OF DETERMINING THE PROPERTIES 



Color. — The color of the extract was observed with the naked 

 eye when a few drops of the substance were allowed to flow down 

 the side of a white porcelain capsule. The results are expressed 

 in shades of green or brown as the case demands. 



Specific gravity. — The specific gravity of the extracts was 

 taken at 25° C. using a 5 cubic centimeter pycnometer and an 

 ordinary chemical balance. Owing to the thick consistency of 

 the substance special precautions had to be taken to eliminate 

 all air bubbles. Warming the extract before filling the pycno- 

 meter has an advantage in this connection. 



Refractive index. — The refractive index was observed at 15° 

 C, using an Abbe refractometer. The results given in the tables 

 are the averages of 5 readings, and are only given to the third 

 decimal place as the deep color of the extract prevents a more 

 exact reading. 



Solubility. — The solubility tests were carried out at 15° C. ; 

 those with ether and acetone being exceptions as they were ob- 



'' Am. Journ. Pharm. (1889), 61, 169. 

 **Pkarm,. Zeitg. (1891), 36, 245-246. 



