xv, 3 Del Rosario and Maranon: Valoration of Tikitiki 228 



It is very remarkable that in the majority of the samples the 

 proportion of nitrogen is higher than that of phosphorus. Ex- 

 tracts 3 and 5, however, show the reverse condition. The amount 

 of phosphorus in extract 3 is one and one-fourth as great as the 

 nitrogen found in the same sample, and compared with the phos- 

 phorus of extract 2 it is six times as high, while the standard 

 sample of the Bureau of Science is one-fourth lower in phospho- 

 rus than extract 3. 



We have obtained uniformly negative results in our attempts 

 'to demonstrate the amyloiytic enzyme. We assume that the 

 reason for this is that the treatment of the extract with alcohol 

 renders the enzyme inactive. 



The figures we have obtained must be considered as being 

 merely approximate, for it is quite apparent that analyses of 

 the different samples of the same manufacturer, prepared at 

 different times, will of necessity yield results that will vary to 

 some extent. This is not surprising in view of the lack of a 

 standard method for the preparation of this drug, to which we 

 already have called attention. In fact, even though the same 

 general procedure were followed, any qualitative variation in 

 the raw material used, the concentration of the alcoholic solvent, 

 the time during which the solvent and drug are in contact, the 

 temperature at which extraction takes place, and the time over 

 which evaporation is allowed to proceed when the vacuum is not 

 employed — all these are factors that must be taken into account 

 in the determination of the percentage composition of the extract. 



The above discussion regarding tikitiki extract has been ad- 

 vanced from the viewpoint of the chemist ; but it should be well 

 borne in mind that systematic clinical studies by the physician 

 must be carried out and carefully interpreted before determina- 

 tion can be made of the most desirable composition and the 

 ultimate standardization of this drug, now so generally admin- 

 istered in the treatment of endemic neuritis. 



