188 '^he Philippine Journal of Science mz 



of this nucleic acid. All 4 fowls developed polyneuritis within 

 thirty days. 



We believe that these confusing results are satisfactorily ex- 

 plained by the fact that the methods commonly used for the 

 extraction of nucleic acid from proteid substances depend upon 

 the use of fixed alkalies. Thus Neumann's (13) much-used 

 method for the preparation of thymo-nucleic acid involves the 

 use of 33 per cent sodium hydroxide, and Slade's(l4) method 

 for the preparation of yeast nucleic acid requires that the yeast 

 be treated with 1.1 per cent of its weight of sodium hydroxide. 

 Alkalies are also frequently used in the preparation of nucleins. 

 We have already said enough concerning the loss of the curative 

 base when treated with alkaline reagents to indicate that such 

 methods would surely destroy it. 



It seems probable to us, therefore, that the' curative base 

 exists in foodstuffs as a constituent of a nucleic acid, as is 

 indicated by the chemical reactions of this base, but that it is 

 not present in the nucleic acid or nucleins obtained from yeast 

 or other substances by the use of alkalies. This accounts for 

 the failures which have resulted so constantly when nucleins or 

 nucleic acids were used as preventive or curative agents. The 

 partial protection reported by Chamberlain and Vedder above 

 may well have been due to the use of a nuclein in which the 

 protective substances had not been completely destroyed, for the 

 origin and method of preparation of this nuclein is unknown. 



It is further known that the nucleic acid obtained from dif- 

 ferent sources differs in chemical composition. Thus the nucleic 

 acid obtained from the thymus gland contains cytosin, thymine, 

 and uracil, while the tritico-nucleic acid obtained from the wheat 

 embryo contains uracil and cytosin, but not thymine. Therefore, 

 it is very probable that this curative base exists as a constituent 

 of certain nucleic acids, but does not occur in every nucleic acid. 



The solution resulting from the acid hydrolysis of the barium 

 acetate precipitate was much too complex to give crystals of the 

 base by simple evaporation. Various methods have been tried 

 to resolve this solution into its constituents, but so far without 

 succeeding in isolating much larger quantities of Funk's base 

 than had been obtained previously. Experiments in this direc- 

 tion are being continued. 



We now wish to report certain experiments which we have 

 performed in the treatment of human cases of beriberi. As a 

 natural result of the great success obtained by the treatment 

 of cases of infantile beriberi with the extract used by Cham- 



