RECENT WORK IN AGRICULTURAE SCIENCE. 



AGRICULTURAL CHEMISTRY. 



The rapid determination of phosphoric acid by weighing the ammonium 

 phosphomolybdate, .1. Gkaftiau (Bill. Assoc. Chini. Siicr. et Distill., 2.'f (1906), 

 No. 3, Pit. 31')-320). — In the method described acid sohitions of phosphates and 

 phosphatic slag, corresponding to 0.2 gni. of material in case of ordinary 

 superphosphates, mineral phosidiates, and phosphatic slags, 0.1 gm. in case of 

 rich phosphates and superphosphates, and O.-i gm. in case of mixed fertilizers, 

 are neutralized Avith ammonia to the point of precipitation, the jn-ecipitate 

 carefully redissolved by nitric acid, and 10 cc. of Petermann's ammonium 

 citrate added. 



The procedure is then the same as with citric acid solutions, the treatment 

 of which is as follows : Using the same amounts of material as in case of acid 

 solution add 2 to .3 cc. of concentrated nitric acid, 10 to 15 cc. of saturated 

 annnonium nitrate solution, 50 to 70 cc. of water, bring to the boiling point, 

 rcnnove the flame, and add GO to 100 cc. of ammonium nitromolybdate. Allow 

 to stand 15 to oO minutes at about 70° C, remove supernatant liquor by means 

 of a sii)hon, collect the precipitate on a small tai'ed filter, and wash carefully 

 with 1 per cent nitric acid. Dry for 2 hours at 105 to 110° C, and weigh. 



C()nii)arisons of this method with the citro-mechanical method showed some- 

 what higher results by the rapid method in case of superphosphates and j^hos- 

 phatic slag, but irregular variations in the case of mixed fertilizei's. 



Contribution to the titration of phosphoric acid, L. Schucht (Zi.sc/ir. 

 Angcic. Chem.. 10 (1!)06), No. 41, 1708-1711: uhsL in Chem. Centhl., 1906, 

 II, No. 20, p. 1582). — This article discusses the influence of concentration, asso- 

 ciated salts (particularly the addition of sodium chlorid), etc., on the results 

 of titration of phosphoric acid and superphosphate solutions with sodiinn hy- 

 (Iroxid and by the oxalate method. 



A contribution to the determination of lime and magnesia, F. AVesthaus- 

 SEB {Ztsclir. AiKjcir. CIiciii.. 19 {I9(ii;), .Vo. ',0. itp. li;S.>. HIS.]; ('hnii. Zt<i., 30 

 (1906). No. 80, p. .98.5).— This is a note on an article presented at the recent 

 meeting of the German Association of Naturalists and Physicians, which dis- 

 cusses the ai)plication in analytical methods of the fact that when water solu- 

 tions of magnesium chlorid are evaporated to dryness and heated a basic salt 

 is formed which is very difficultly soluble in water, cjilciuni chlorid under the 

 same treatment remaining readily soluble in water. 



Description of a calcimeter, X. Passerini (Staz. Sper. Af/r. Hal., .W (1906), 

 No. 1-2, pp. 28-32, fuj. 1; iihs. in Cliriii. Ccuthh, 1906, II, No. 12, p. 1019, 

 fi(f. 1). — A simple apparatus for determining lime in soils by means of carbon 

 dioxid evolved on treatment with ;icid is described. 



Chemical soil analysis, E. A. MrrsciiEULicii (Fiihliiii/'s Laiidir. Zii/., 5,5 

 (1906). No. //. pp. 361-,i7S). — A general discussion of this subject, lieing in a 

 sense a preliminary notice of the author's treatise on soils, in which methods 



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