RECENT WORK IN AGRICULTURAL SCIENCE. 



AGRICTJITURAL CHEMISTRY— AGROTECHNY. 



A simplification in the methods for calculating analytical results, A. 

 ScHOL7> (Clieiii. Zt<h, 3', (1010), No. 121, pp. 1079, lOSO) .—\ttev discussing the 

 simplified methods for calculating phosphoric acid from magnesium pyrophos- 

 phate, the total dry substance in milk, and the copper from cupric oxid. the 

 author describes methods for shortening the calculations for determining sugar 

 and nitrogen in various products, and acetic acid in vinegar. 



Determination of phosphoric acid in superphosphates and bone meal, Z. 

 RoMANSKi (Clicm. Ztg., 85 {1911), No. 18, pp. 163, 16J,; abs. in Jour. 8oc. Chem. 

 Indm., 30 (1011), No. o, p. 297). — The work shows that if the precipitate ob- 

 tained with magnesium mixture and ammonium citrate is washed with alcohol 

 it will consist of 97 per cent of ammonium magnesium phosphate and 3 per cent 

 of other matter, chiefly magnesium ammonium citrate, which makes such precipi- 

 tates appear black after ignition and are only whitened with difficulty. In order 

 to prevent such impurities the author recommends that the ammonium citrate 

 and magnesium salt solution be acid in reaction, and to add these to the aqueous 

 extract of the superphosphate under examination and slowly precipitate with 

 ammonia. By doing this a crystalline precipitate of ammonium magnesium 

 phosphate is obtained which is of uniform composition. 



The preparation of the reagents and the detaileti method of conducting the 

 procedure are described. The results obtained by this method agree well with 

 those obtained with Wagner's method. 



A new procedure for determining sulphuric acid and sulphates, V, Auger 

 and M. Gabillon (Compt. Rend. Acad. Sci. [Paris], 152 (1911), No. 8, pp. Ui- 

 'i'i3). — The method rests on the principle of reducing the sulphuric acid or 

 sulphate with hydriodic acid, and determining the hydrogen sulphid formed by 

 titration with iodin solution. 



Biochemical classification of the proteins, E. Hauser (Abs. in Chem. Ztg., 

 34 (1910), No. 95, pp. 8J,8, 8.'/9).— This classification differs from the purely 

 chemical one in so far that it considers the biogenetic relation of these bodies 

 to metabolic processes. 



On the refractive indices of solutions of certain proteins. — V, Gliadin, 

 T. B. Robertson and J. E. Greaves (Jour. Biol. Chem., 9 (1911), No. 3-^, pp. 

 181-184 ) . — " The value of a, in the equation iir^ni=a X c where n is the refractive 

 index of the solution of the protein, ?h that of the solvent and e is the percentage 

 concentration of the protein, has been determined for gliadin in various solvents. 



" In the less highly refractive solvents the introduction of gliadin increases 

 the refractivt index ; but in the most highly refractive solvent employed, namely 

 75 per cent phenol, the addition of gliadin reduces the refractive index." 



Fractional precipitation of milk proteids, A. J. J. Yandevelde (Biochem. 

 Ztschr., 29 (1910), No. 6, pp. .',61-464). — The author in a previous work" has 

 pointed out that certain transformations can occur between casein and albumin, 

 and with another protein which occurs in colostrum. He furthermore expressed 

 the opinion that casein and albumin were chemically not indis'idual substances, 

 and suggested a nomenclature, a for milk protein precipitated by an acid, /3 for 

 that protein precipitated from the filtrate from a by the aid of heat, and a third 

 mentioned as y. 



« Biochem. Ztschr., 7 (1908), p. 396. 

 14-867''— No. 8—11 2 709 



