OFFICIAL METHODS OF ANALYSIS OF FERTILIZERS AND 



FEEDING STUFFS ADOPTED BY THE BELGIAN STATE 



LABORATORIES AND THE AGRICULTURAL 



EXPERIMENT STATIONS OF HOLLAND. 



The State laboratories of Belgium and the agricultural experiment 

 stations of Holland have recently adopted uniform methods for the 

 analysis of fertilizers and feeding stuffs. While the methods are, as a 

 rule, very similar to the official methods in this country and in Ger- 

 many, they differ somewhat in the details of execution. The following 

 condensed account of the methods is taken from the bulletin of the 

 Belgian Minister of Agriculture. ' 



ANALYSIS OF FERTILIZERS. 



Ammoniacal nitrogen. — Amnion iacal nitrogen is determined by dis- 

 tilling 50 cc. of a solution prepared by dissolving 10 gm. of sulphate of 

 ammonia in 1 liter of water with calcined magnesia, the ammonia being 

 collected in 20 cc. of one half normal sulphuric acid and the excess of 

 acid titrated with alkali, preferably one-fourth normal barium hydrate. 



Nitric nitrogen. — For the determination of nitric nitrogen two meth- 

 ods may be employed, the Schloesing-Grandeau and the Ulsch methods. 

 In the first case, with nitrate of soda, 10 cc. of a solution containing 1G.5 

 gm. of the nitrate per liter is used; with nitrate of potash the same 

 amount of a solution containing 20 gm. of the nitrate per liter is used. 

 The solution of nitrate is treated in a Schloesing apparatus with 50 cc. 

 of a solution of ferrous chlorid saturated in the cold and an equal vol- 

 ume of concentrated hydrochloric acid, rinsing the funnel with dilute 

 acid (1 to 1). The results obtained are compared with those obtained 

 by the same treatment of 10 cc. of type solutions containing 33 gm. of 

 pure nitrate of soda or 40 gm. of pure nitrate of potash per liter. The 

 receiver for the gas is filled with cold distilled Avater recently boiled. 

 Air is expelled from the apparatus by introducing a little nitrate. 



The form of Ulsch method used (not applicable in the presence of 

 ammoniacal salts) is as follows : To 25 cc. of a solution prepared by 

 dissolving 10 gm. of the substance in 1 liter of water 5 gm. of iron 

 reduced in hydrogen and 10 cc. of dilute sulphuric acid (1 volume of 

 concentrated acid to 2 volumes of distilled water) are added in a i-liter 

 flask, which is connected with a condenser. The solution is heated 



1 Bui. Min. Agr. [Belgium], 1898, No. 3, pp. 18. 

 304 



