ABSTRACTS OF REPORTS OF EUROPEAN INVESTIGATIONS. 



Official methods of analysis adopted by the Association of Agricultural 

 Experiment Stations in the German Empire,* September 18 and 19, 

 1890 {Landiv. Versuchs-^Stationen, 38, pp. 281-313). 



ARTIFICIAL FERTILIZERS. 



Preparation of the sample. — The sample is to be screened aud well 

 mixed; iu the case of moist materials the screening may be omitted. 

 As soon as received the sample is to be weighed and divided into two 

 parts, one to be used for analysis and the other to be i^reserved in a 

 tight jar iu a cool place for three months. Iu crude phosphate and 

 bone-black the moisture is to be determined at 105-110° C; and iu 

 samples which may lose ammonia during drying, the ammonia is also 

 to be determined. Where an analysis is to be controlled by another 

 chemist, the sample, at least 250-500 grams, is to be seut iu a tightly 

 closed jar, accompanied by a statement of its weight. With sub- 

 stances liable to lose water by grinding the moisture is to be deter- 

 miued in both the coarse aud the grouud material, aud the results of 

 analysis calculated for the moisture of the uuground (original) material. 



Fertilizers containing phosphoric acid. — TLe solution of the soluble 

 phosphoric acid is to be made by shaking 20 grams of superphosphate 

 iu a liter flask with 800 c. c. water duriug 30 minutes, filling with water 

 to the liter mark, and filtering. The use of a shaking machine making 

 one hundred and fifty revolutions per minute is recommended. (This 

 regulation goes into effect January 1, 1891.) The solution coutaiuiug 

 double superphosphate is to be heated with nitric acid (10 c. c. cone. 

 HNO3, sp. gr. 1.4, to 25 c. c. of the superphosphate solution) to change 

 any pyrophosphoric to tribasic acid. In control analyses the molyb- 

 date method is to be employed. In estimating iron and alumina iu raw 

 phosphates the Glaser method is recommended. According to this 

 method 5 grams of phosphate are dissolved iu 25 c. c. nitric acid of 1.2 

 specific gravity and 12.5 c. c. hydrochloric acid of 1.12 specific gravity, 

 the solution made to 500 c. c, filtered, and to 100 c. c. of the filtrate 

 (= 1 gram of substance) iu a 250 c. c. flask, 25 c. c. sulphuric acid of 

 1.84 specific gravity added. After standing about 5 minutes, the con- 

 tents of the flask are shaken, 100 c. c. of 95 per cent alcohol added, 



*Scc Esperimeut Station Record, Vol. I, p. 175, 



