xv, 3 Del Rosario and Maranon: Valoration of Tikitiki 223 
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 amylolytic 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. 
