RECENT WORK IN AGRICULTURAL SCIENCE. 



AGRICULTURAL CHEMISTRY. 



Agricultural chemistry, A. ;Mow,en and G. FiNOEur.TNr. (Jalirh. Chrm., 

 11 il!)07), pp. 285-^99).— This is a review for the year 1907, and, as usual, 

 contains biographical notes, references to imimrtant discoveries in analytical 

 methods, and a review of chemical investigations relating to air and water, 

 soils, fertilizers, and plant and animal physiology. 



Chemical industry in relation to agriculture, A. Frank (Jour. Soc. Chan. 

 Indus., 21 iWOS), No. 22, pp. 1093-1100).— This article shows the close relation 

 between chemical indnstry and agriculture, particularly in the production of 

 phosphates, potash salts, and nitrogen compounds. Especial attention is given 

 to the progress and present status of the manufacture of nitrogen compounds 

 from the air by electric processes. 



The behavior of metallic aluminum in contact with milk, wine, and some 

 salt solutions, F. voN Fillinger (Ztschr. Untersuclt. Xahr. u. Gcitu.^i^mtl., 

 16 (1908). \o. Jf, pp. 232-234)- — An investigation undertaken with reference to 

 the use of aluminum for cooking utensils showed that fresh milk did not dis- 

 solve an appreciable quantity of it, while the serum of very sour milk dissolved 

 only traces. When wine was cooked in ahiminum none of the metal was 

 dissolved. 



On the precipitation of magnesium as ammonium-magnesium, phosphate, 

 E. Kaffa (Gaz. Chim. ItaL, 38 (1908), II, Xo. 6, pp. 556-566; ahs. in Analyst. 

 34 (1909), No. 395, p. 73; Ztschr. Angeic. Chem., 22 (1909). No. 9, pp. 397. 398; 

 Jour. Chem. Soc. [Lnmlon], 96 (1909), No. 556, II, pp. 183, 18.',).— The author 

 discusses conditions affecting the accuracy of the determination of magnesium 

 bj^ precipitation with sodium-ammonium phosphate. 



A volumetric method is proposed as follows : To 40 cc. of half-normal sodium- 

 ammonium phosi)hate in a wide-mouthed flask add rapidly 10 cc. of the solution 

 in which magnesium (0.3 to 0.5 gm.) is to be determined; shake the mixture 

 and allow to stand until precipitation is complete; filter through a dry filter or 

 remove the clear liquid with a pipette. To an aliquot part of the solution add 1 

 to 2 cc. of concentrated acetic acid and determine excess of phosphoric acid by 

 means of uranyl acetate in the usual way. 



If a gravimetric procedure is preferred, the precipitated ammonium-magne- 

 sium phosphate (using 20 to 25 cc. of sodium-ammonium pliosphate) may be 

 collected on a filter, washed with 2.5 per cent ammonium solution, ignited, and 

 weighed in the usual way. 



The theory of the titrametric determination of phosphoric acid (Phnrm. 

 ZcntralltaUc, .',9 (IH08), No. 51, pp. UI35-I037) .—TW theory and calculation 

 of results of preciiiitation as ammonium phosphomolybdate and ammonium 

 magnesium phosphate weighed as magnesium pyrophosphate are briefly 

 explained. 



Volumetric determination of water-soluble phosphoric acid in superphos- 

 phates, L. SCHUCHT (Chem. Ztg., 32 (1908), No. 99, pp. 1201, 1202; abs. in 

 1006 



