24 EXPERIMENT STATION EECOED. 



The influence of green manuring with mustard and peas at various stages 

 of growth and of different kinds of nitrogen manuring on denitrification, 

 A. Bartels (Jour. Landiv., 5S {1910), No. 2, pp. UiS-lOS, pis. -'/).— A series of 

 pot experiments are reported which for the most part gave inconclusive results. 

 The attempt to trace some definite relation between denitrification and the 

 amount of pentosans supplied to the soil by the different methods of manuring 

 was not entirely successful on account of the important part played by other 

 factors in determining the yield. 



The fixation of atmospheric nitrogen (ScL Amer. Sup., 70 (1910), No. 181 Jf, 

 pp. 233, 234, flQs. 6).' — This is a brief account of the Pauling process of the elec- 

 tric fixation of nitrogen as used in a factory at Patsch, near Innsbruck, Austria. 



The nitrogen of the air. — Waterfalls and agriculture, L. Grandeau (Jour. 

 Soc. Cent. Agr. BeJg., 51 (1910), Nos. 6, pp. 114-116; 1, pp. 199, 200; 8, pp. 222, 

 223).— This is a review of the development and present status of the various 

 processes which have been proposed for the utilization of cheap water power 

 in generating electricity for the manufacture of nitrogenous fertilizers from the 

 free nitrogen of the air. 



Progress in potash industry, H. Hof (Cliem. Ztg., 34 (1910), No. 50, pp. 

 445, 446). — The various recent contributions to the geology, mineralogy, chem- 

 istry and technology of this industry are noted. 



Potassium silicate as a source of potash for plants, D. N. Prianishnikov 

 and A. G. Doyarenko (Dnevn. XII. S"iesda Ross. Est.-Isp. i Vrach., No. 8, p. 

 345; ahs. in Zliur. Opuitn. Agron. (Russ. Jour. Expt. Landic), 11 (1910), No. 

 1, p. 101). — A species of nepheline from the coast of the White Sea proved to 

 be a good source of potash for plants, but as this species also contains biotite, 

 and muscovite and biolite proved to be better sources of potash in sand cultures 

 than elseolite, it is possible that its action is due to the presence of biotite. 

 The group of feldspars (orthoclase, microcline, sanidine) were of very little 

 value as potash food. Leucite was also of much less value in this respect than 

 the samples of biotite (especially micaceous schists) used. The potash of 

 hydrous silicates which were used in some of these experiments was much less 

 available than that of other silicates tested. 



Potassium silicate, Brehmer (Gartenwelt, 14 (1910), No. 19, pp. 220-222, 

 figs. 3). — Potassium silicate (phonolite) was compared with 40 per cent potash 

 salt on various kinds of vegetables and flowers. The results as reported are 

 generally favorable to the silicate. 



Economic geology of the feldspar deposits of the United States, E. S. 

 Bastin (U. S. Geol. Survey BuJ. 420, pp. 85, /)?s. 8). — "The present bulletin 

 brings together in a single volurue all available practical information concern- 

 ing the commercial feldspar deposits of the United States. Scientific problems 

 are discussed only so far as they are of commercial importance or so far as 

 the discussion may contribute to a general understanding of the deposits." 

 Deposits of economic importance in Maine, Massachusetts, Connecticut, New 

 York, Pennsylvania, Mai'yland, Virginia, Wisconsin, Minnesota, and Texas are 

 described. 



Reference is made to the interest aroused in the use of potash feldspar as a 

 fertilizer by the work of A. S. Cushman of this Department (E. S. R., 19. p. 

 322) on the availability of the potash of ground feldspar and on methods of 

 extracting the potash. It is stated that of the various processes of extraction 

 which have been patented none has yet been successfully applied on a commer- 

 cial scale. 



A review of the phosphate fields of Idaho, Utah and Wyoming, W. H. 

 Waggaman (Amer. Fert., 33 (1910), Ifo. 5, pp. 1-15). — This is a summary of 



