RECENT W()KK IN AGRICULTURAL SCIENCE 



AGRICULTURAL CHEMISTRY. 



The practice of agricultural chemists, M. Passon I Dit Praxis des Agrikultur 

 ehemikers. Stuttgart: Ferdinand Enke, 1905, pp. VIII 295, pis. 5). This 

 describee the various materials which the agricultural chemisl is likelj \<< be called 

 upon t<> examine, ami gives in some detail the analytical methods suited t" Bueh 

 examination. 



The subjects treated are fertilizers, including various forms of nitrogenous, phos- 

 phatic, and potash fertilizers, mixed fertilizers, calcareous manures, fraudulenl ferti- 

 lizers, barnyard manure, composts, and night soil; the soil, including investigation 

 of various soil types, the valuation of soils on the basis of chemical analysis, -oil tests 

 with fertilizers, ami the examination of the products obtained in such tests; feeding 

 stuffs, including various by-products of oil making, milling, and other industries; 

 and briefer sections relating to milk, butter, margarin, water, and Beed. 



On the determination of magnesium and phosphoric acid as magnesium 

 pyrophosphate, K. K. Jarvinen (Ztschr. Analyt. < 'in m., 4 ', \ 1905 . No. 6 7, p\ 

 842; abs. in Jour. Chem. Soc. [Londori],88{ 1905), No.5U, TI, p. 555) .—In the method 

 proposed the solution, which should not contain a great excess of ammonium salts, 



is exactly neutralized, using lacmoid as indicator. A slightly ami riacal solution of 



diammonium phosphate is then added drop by drop. 



When time has been given for the greater part of the precipitate to separate 1 per 

 cent ammonia is added and then 10 per cent ammonia in quantity equal to on. --third 

 of the volume of the whole. After standing 2 hours the precipitate is collected on a 

 Alter, dried, ignited over a Bunsen flame, and weighed. Ammonium oxalate in 

 moderate quantity has no effect on the precipitation. 



An alkalimetric method of determining phosphoric acid in the presence of 

 other acids and its application in the examination of phosphatic materials. 

 Y. Boulez (•'• Internal. Kong. Angew. Chem., 1903, Ber.8,pp. 746, 747). — The method 

 (abased upon the difference in behavior of phosphoric acid and other arid- toward 

 methyl orange and phenolphthalein as indicators. 



Further notes on simple methods of determining potash, I'. Klinkerfi bs 

 [Chem. Ztg., 29 (1905), No. 81, pp. 1085, 1086). — Referring to his previous note on 

 this subject i E. S. K., 16, p. 843 I, the author calls attention to the fact that it is not 

 accessary to evaporate to complete dryness after the addition of formic acid, and that 

 by taking advantage of this fact the operation is greatly shortened. He also describes 

 an adaptation of his method for potash to the determination of nitrogen in potash- 

 free ammonium salts. 



The new Paul Wolff apparatus for the determination of lime in high 

 percentage marls, 1'. Bommbb (Devi. Landw. I' p. 692, 



fig. /i. The apparatus described i- adapted to marls containing over 50 percent of 

 calcium carbonate. Two gm. of the marl is decomposed by boiling with 50 cc. ■•! 

 normal hydrochloric acid, foi which a special pipette is provided. The .- 

 acid is titrated (using phenolphthalein as indicator) with j normal Bodium hydroxid 





