RECENT WORK IN AGRICULTURAL SCIENCE. 



CHEMISTRY. 



Proceedings of the seventeenth convention of the Association of Agricul- 

 tural Experiment Stations in the German Empire {Landw. Vers. Stat, 57 

 {1902), No. 1-2, pp. 1-101). — The .seventeenth meeting of this association was held 

 at Hamburg September 21 and 22, 1901, and was presided over by the president, F. 

 Nobbe. 



Among the subjects under consideration were the determination of citrate-soluble 

 phosphoric acid in Thomas slag, the Neubauer method of potash determination, the 

 Gunning modification of the Kjeldahl method of nitrogen determination, the allow- 

 able water content of molasses feeds, and their analysis, the determination of potash 

 salts in mixed potash fertilizers, fundamental principles in the examination of bran, 

 the relation of the agricultural experiment stations to the work of the association, 

 the preparation of feeding stuffs for analysis, with directions for sampling, the 

 changes produced by micro-organisms in foods and feeding stuffs during storage ( E. 

 S. R., 13, p. 581), the microscopical examination of rape-seedcake, the money value 

 of feeding stuffs, and the present status of the movement for the introduction of 

 uniform atomic weights. 



An unfavorable report upon the accuracy of the Neubauer method was made by 

 Soxhlet and no action was taken by the association. Comparative tests of the Gun- 

 ning modification of the Kjeldahl method (E. S. R., 14, p. 118) and the method of 

 the association on different feeding stuffs were reported by Kellner. Further testing 

 of the Gunning modification was recommended. A water content of 20 per cent in 

 molasses feed and 25 per cent in jieat molasses was adopted as allowable. The 

 determination of molasses in molasses feeds was assigned for further study. The 

 recommendation was adopted that potash in fertilizers be reported only as K^O. 

 Wittmack discussed the purity of bran and its determination, and reported several 

 feeding experiments with different animals. It was recommended that all feeding 

 stuffs for analysis should be prepared fine enough to pass through a 1-mm. sieve. 

 Emmerling discussed the microscopical examination of rape-seed cake, A commit- 

 tee of three was appointed to determine the relative value of nutrients — protein, fat, 

 and carbohydrates— in feeding stuffs and report annually to the association. 



The action of distilled water upon lead, F. Clowes {Cliem. Npws, S6 (1902), 

 Ao. 223i;, j). 168). — The author found that when lead was placed in contact with 

 ordinary distilled water a white deposit was formed which contained lead and a cer- 

 tain amount of lead went into solution in the water. The lead in solution appeared 

 to be in the form of hydroxid. That in the white deposit was found to be a hydroxy- 

 carbonate containing three molecules of carbonate to one of hydroxid. Investiga- 

 tions in which bright sheet lead of great purity was exi)osed to the action of boiled 

 distilled water iu vacuo or in different gases showed "that dissolved oxygen is the 

 cause of the action of distilled water upon lead, the subsequent action of carbonic 

 acid leading to the i)roduction of hydroxycarbonate." 

 544 



