SOILS FERTILIZERS. 725 



fertilizers " that a number of agencies are concerned in crop production, and 

 that in order to secure the best results and develop a permanent system of 

 agriculture all these factors must be taken into consideration." 



Fertilizer economics, H. G. Bell (Abs. in Science, n. ser., 35 (1912), No. 

 S9S, p. .J~'7). — This is an abstract of a paper presented at the Washington meet- 

 ing of the American Chemical Society in 1911, dealing with the economic im- 

 portance of the rational use of fertilizers. 



The American fertilizer handbook, 1911 (Philadelphia, 1911, pp. 296, figs. 

 IS). — In addition to the usual fertilizer manufacturers', cotton-seed oil mill, 

 allied fertilizer trades, and foreign directories, this handbook contains the fol- 

 lowing special articles: The Florida Phosphate Deposits, by E. H. Sellards; The 

 Three Essential Elements of Plant Food, by W. H. Bowker ; Florida Phosphate 

 Rock Shipments, 1909-10; Phosphate Rock Statistics; The Value of Ccmimercial 

 Fertilizers, by J. D. Toll; Sulphuric Acid Tables; Fertilizer Materials (annual 

 review of the New York market) ; Chicago Ammoniate Market, by A. L. Sardy; 

 Inorganic Nitrogenous Plant Foods, by F. J. Machalske ; and Average Yields of 

 Farm Crops. 



Report of cooperative fertilizer and variety tests, 1911, O. H. Laesen (Ber. 

 Landhofor. Virks. PJanlcarl. i<jiiUan4, 1911, pp. 336, figs. 13). — The report con- 

 tains accounts of the activities of the various agricultural societies of Zeelaud 

 during the yeai', especially cooperative variety and fertilizer tests. These cov- 

 ereil 281 different trials with artificial fertilizers and lime for small grains, 

 legumes, hay, and root crops, tests of the residual effects of artificial fertilizers, 

 comparisons of different nitrogenous fertilizers (nitrate of soda, Norway nitrate, 

 lime nitrogen, and ammonium sulphate), and experiments with lime, marl, and 

 land plaster. The plant culture trials included 200 series of variety tests with 

 small grains and root crops, and other experiments along similar lines as in 

 previous years. 



The importance of nitrate in the treatment of sewage and sludge, F. Guth 

 and P. Keim (Gsndhis. Ingcn., 35 (1912'), No. .'/, pp. 57-62). — This article re- 

 ports a study of the effect of added nitrate on the decomposition of sewage, in 

 which it was found that added nitrate acted like that produced in the ordinary 

 course of mineralization of nitrogenous matter in controlling within certain 

 limits the purification of the sewage, but that the nitrate remained inactive 

 except in the presence of bacteria. 



The effect of the " wet process " on the availability of low-grade nitrog- 

 enous materials, B. L. Haktwell and F. R. Pember (Ahs. in Science, n. ser., 

 85 (1912), No. 89S, p. 426). — In this abstract of a paper presented at the Wash- 

 ington meeting of the American Chemical Society in 1911 a brief account is 

 given of pot experiments on two different soils, in which hair tankage, gar- 

 bage tankage, and roasted leather were used both before and after having 

 been subjected to digestion in the presence of phosphate rock and sulphuric 

 acid (the "wet process"). The crops grown were Japanese millet (2 crops), 

 oats (2 crops), and buckwheat (1 crop). 



"The nitrogen of the garbage tankage had a very low availability both 

 before and after ncidulation ; while that in roasted leather and hair tankage, 

 although of low availability before, was much more available after, treatment. 



"The treatment by the * wot process' of these nitrogenous materials indi- 

 vidually was conducted in the laboratory, but a mixture of the three was 

 treated by the regular ' wet process ' in a fertilizer factory. Over 70 per cent 

 of the nitrogen in the ' base goods ' so manufactured was soluble in water and 

 highly available, but the insoluble nitrogen was of no immediate value." 



The calcium carbid industry (Abs. in Daily Cons, and Trade Rpts. [U. S.], 

 15 (1912), No. 31, p. 569; Amer. Fert., 36 (1912), No. 3, pp. 42, 43).— The Lon- 



