New York Agricultural Experiment Station. 141 



as in the various reactions tried in these experiments only esters 

 were produced, and at lower temperatures apparently no reaction 

 takes place. These compounds are in physical and chemical prop- 

 erties very similar to phytic acid. They form analogous acid salts 

 which in appearance and solubility seem almost identical with salts 

 of phytic acid. Whether esters, such as above, are found in nature 

 is at present unknown. It is, however, not impossible that a part 

 of the organically bound phosphorus existing in plants may be present 

 in some such, or similar, forms. 



The silver salts previously referred to were prepared in the hope 

 that they might serve for the preparation of an ester of phytic acid with 

 which molecular weight determinations might be made. As was to be 

 expected, however, only acid salts were obtained and, as such, were 

 quite useless for the purpose in view. In the reaction between 

 phytic acid and silver nitrate, nitric acid is of course liberated and 

 when any strong acid is present only acid phytates are obtained. 



Efforts made to prepare an ester by acting on sodium phytate 

 with methylsulphate proved useless as no ester could be isolated. 

 Further experiments along this line are contemplated and will be 

 reported later. 



In an article concerning the phosphorus compounds found in food 

 materials which appeared in a Swedish chemical journal little known 

 in this country and which is not abstracted by any of the larger 

 chemical journals, a valuable contribution to the chemistry of phytin 

 was made by A. Rising.^ Among other things he describes a silver 

 phytate of the following composition: C 5.5, H 1.08, P 13.2 and 

 Ag 52.65 per ct., from which results he concludes that it must 

 represent a complex pyrophosphoric acid compound of inosite. It 

 is noteworthy that this author and E. Starkenstein,^ independently, 

 and practically at the same time expressed the same opinion, viz: 

 that phytin represents a complex pyrophosphoric acid compound of 

 inosite. 



The silver salt described by Rising corresponds to the hepta-silver 

 phytate mentioned in this paper. He proposes the following empiri- 

 cal formula : C6Hi4Ag6P5022, but his results agree equally well with 

 a hepta-silver phytate: C6Hi7027P6Ag7. 



Found by Found for hepta-silver phytate 

 Calculated Rising -] in this laboratory 



C 4.92 5.50 



H 1.16 1.08 



P 12.72 13.20 13.02 per cent. 



Ag 51.64 52.65 52.43 per cent. 



From the above there appears to be no doubt that these salts are 

 identical. 



^Svensk Kemisk Tidskrifl 22: 143 (1910). 



Note. — I am indebted to Mr. A. R. Rose of Columbia University for this as well 

 as for many other valuable references to literature. 



^Loc. dt. 



