1912] 'Anton Richard Rose 39 



Stutzer in Germany and Forbes in this country, working inde- 

 pendently, introduced a new idea in the determination of inorganic 

 phosphorus, namely, the use of acid alcohol. Forbes and bis asso- 

 ciates make an acidulated water extract and precipitate with mag- 

 nesia mixture; the precipitate is then washed successively with 

 ammonia water and alcohol, and the inorganic phosphorus separated 

 f rom the phytins by digesting in cold 95 per cent. alcohol containing 

 0.2 per cent. of nitric acid. This alcoholic Solution is finally filtered, 

 the filtrate evaporated, and phosphorus determined in the residue 

 in the usual way. 



Starkenstein has studied in some detail the application of titra- 

 tion methods to this problem, and his results point to the possibility 

 of determining quantitatively these different forms of phosphorus 

 in the same Solution. He found that titration of a Solution con- 

 taining ortho-phosphate, pyro-phosphate and inosite-phosphate with 

 uranyl acetate standardized by ortho-phosphate, using cochineal as 

 an indicator, gave in each case true values for total phosphorus; 

 that with ferrocyanide as an indicator, the total phosphorus was 

 equivalent to all of the phosphorus as ortho-phosphate, one half of 

 that as pyro-phosphate and inosite-phosphate, the glycero-phosphate 

 not entering into the reaction at all. Anderson notes that pyro- 

 phosphoric acid can be converted into the ortho form by heating 

 with dilute acids, while the inosite-phosphoric acid is not affected 

 by this treatment. With these facts in mind a Volumetrie process 

 may readily be devised. 



THE ROLE OF INOSITE-PHOSPHORIC ACID AND ITS 

 SALTS IN PLANTS 



The literature on phosphorus metabolism in animals has become 

 voluminous, but the botanists have published comparatively little on 

 the changes of these Compounds and their probable significance in a 

 plant's life history. That cell functioning is impossible in the 

 absence of phosphorus is again emphasized in the recent work of 

 Frouin,^^ which shows its absolute necessity in the growth of 

 micro-organisms. The study of the role of phytin in plant life in- 

 volves an investigation of the changes and distribution of all the 



^'Frouin: Compt. Rend. Soc. Biol., 1910, 68, 801-803. 



