RECENT WORK IN AGRICULTURAL SCIENCE. 



CHEMISTRY. 



Proceedings of the fifteenth convention of the Association of Agricul- 

 tural Experiment Stations in the German Empire [Lundiv. ]'erx. >S((il., 56 

 {1901), No. 1, pp. 1-79). — The fifteenth annual meeting of this Association was held 

 in Bonn, September 14 and 15, 1900, Prof. F. Nobbe presiding. 



Among the subjects considered in relation to fertilizers were the determination of 

 phosphoric acid in Thomas slag, the perchlorates in saltpeter, the })otash content of 

 potash salts, and the purity of magnesium pyrophosphate obtained in the analysis 

 of slag. The subject of food analysis was confined mainly to the examination of 

 molasses feeds, attention being given more especially to the determination of fat, 

 molasses, and water content. In seed testing there were considered methods of testing 

 and effect of mechanical injury upon the germinating quality. Among the general 

 subjects discussed were the changes in atomic weights, and the condition and needs of 

 the agricultural experiment stations. 



The methods of analysis of Thomas slag were.considered at some length, especially 

 the limits of variability allowable in the citrate-soluble method. The latitude 

 adopted for citrate-soluble phosphoric acid in Thomas slag was 0.5 per cent. 



A report was suljmitted upon the purity of magnesium pyrophosphate obtained 

 from phosphatic slag l)y the direct and l^y the molybdate methods. A table show- 

 ing comparative results of the 2 methods was given. It was found that by the molyb- 

 date method too high results were obtained when the yellow precipitate was allowed 

 to stand a certain time before filtering. This period in which the error occurred fell 

 between 1 and 5 hours. It was recommended that the Wagner method be further 

 studied, as to the influence of the time elapsing between the removal of the molyb- 

 date precipitate from the water bath and its filtration; also, the influence on the 

 result of adding a greater or less excess of magnesia. 



The methods of analyzing molasses feeds were discussed at some length, Neubau- 

 er's methods of determinmg molasses in such feeding stuffs was adopted jjrovisionally. 



The subject of the composition of sugar-beet molasses was presented by Kellner. 

 This considered the sugar and the nitrogen content of the usual refinery molasses 

 with and without the presence of cane sugar, and the residual molasses from the 

 strontium process. The results of the various analysts were given. The nitrogen 

 content of the dry matter of ordinary mola.sses averaged 2.16 per cent; of the residual 

 molasses from the strontium process 0.69 per cent. 



Schulze discussed the water content of molasses feeds and recommended it as a 

 subject for further study. 



A report on molasses feeds was made Ijy Emmerling, and the nitrogen content, 

 fat, dry matter, sugar, molasses, and water content discussed. The quality and the 

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