EXPERIMENT STATION RECORD. 



Vol. XXVI. Abstract Number. No. 6. 



RECENT WORK IN AGRICULTURAL SCIENCE. 



AGRICULTURAI CHEMISTRY— AGROTECHNY. 



Some investigations in regard to the phosphorus compounds in plant 

 seeds, especially phytin, W. Vorbrodt (Bui. Inicrnat. Acad. 8ci. Cracovie, CI. 

 8ci. Math, et Nat., 8er. A, 1910, No. 8, pp. 1,14-511, pi. 1).—The author first in- 

 vestigated the different methods for determining the various forms of phos- 

 phorus in plants, etc., and came to the conclusion that the best way for esti- 

 mating the free (inorganic) phosphoric acid is by means of the triple precipi- 

 tation method, in which the phosphoric acid is first precipitated with magnesia 

 mixture, the precipitate dissolved in nitric acid (1 per cent), and the final am- 

 monium phosphomolybdate compound precipitated with barium chlorid, ac- 

 cording to Riegler's method (E. S. R., 14, p. 736). Determinations were also 

 made of the soluble organic compounds contaiaing phosphorus by taking the 

 difference between the phosphoric acid extracted with 1 per cent acetic acid 

 solution or 0.2 per cent hydrochloric acid and the total phosphoric acid in the 

 same solution by Neumann's method. The determination of lecithin phosphoric 

 acid is also discussed. 



The determination of the phosphorus content of the proteins can be made in 

 two ways, either by digesting the material with dilute acid to remove soluble 

 phosphorus compounds and then determining the phosphorus in the residue, or 

 by taking the difference between the total phosphoric acid and the phosphoric 

 acid soluble in acetic acid and the phosphoric acid content of the lecithin. The 

 author prefers the latter method. 



The second part of the study deals with the amounts of the various kinds of 

 phosphorus present in seeds. It was found that the most total and the least 

 lecithin phosphorus were present in oil-bearing seeds {Cwtinabis satira contain- 

 ing 1.74 per cent and Picea excelsa 1.57 per cent of total phosphoric acid). 

 Cereals and leguminous seeds contained an average of about 1 per cent. Oil 

 seeds were also usually highest in protein phosphorus. 



In part 3, which considers the enzymatic decomposition of the organic phos- 

 phorus compounds, it is noted that the organic phosphorus compounds of bar- 

 ley and maize seeds, soluble and insoluble in 1 per cent acetic acid solution, 

 can be decomposed by enzyms with the splitting off of inorganic phosphoric 

 acid. The cleavage at the outset proceeds uniformly and from the curve ob- 

 tained it is possible to estimate the Inorganic phosphoric acid content of barley 

 flour approximately. 



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