120 EXPERIMENT STATION RECORD. 



anski mineral medium containing varying amounts of sodium carbonate (0.15 to 1 

 gm. per 1,000). 



From the results it is concluded that the amount of sodium carbonate may be 

 reduced to 0.2 gm. per 1,000 without inconvenience, and if it does not exceed 0.25 

 gm. the transformation of nitrite is not interfered with by the addition of ammonium 

 sulphate to the medium. If, however, larger amounts are present the free ammonia 

 (but not the ammonium carbonate I formed retards the action of the nitric ferment. 



Nitrification, L. Grandeau {Jour. Agr. Prat., n. ser., 9 (1905), No. 10, pp. 300, 

 301).— A brief history of the discovery of the true nature of this process. 



Nitrifying- organisms, L. Grandeau (Jour. Agr. Prat., n. ser., 9 (1905), No. 11, 

 pp. 332, .133).— A brief account of the discovery by Winogradski of the fact that 

 these organisms can develop normally in a purely mineral medium. 



Nitrification in the soil.— The nitrous organism, L. Grandeau {Jour. Agr. 

 Prat., n. ser., 9 (1905), No. 12, pp. 369, 370).— This is a brief discussion of the inves- 

 tigations of Winogradski and others on the transformation of organic nitrogen first 

 into ammonia, then into nitrous acid, and finally into nitric acid. 



Nitrogen-fixing bacteria, H. Fischer (Jour. Landw., 53 (1905), pp. 61-66; abs. in 

 Jour. Chem. Soc. [London], 88 (1905), No. 509, II, p. 189) .—Of 6 samples of soil from 

 differently manured plats only 2 from plats which had received lime were found to 

 contain Azotobacter. The original soil of the plats was a heavy loam with only 

 0. 145 per cent of lime. 



The bacterial flora of the soil, L. Grandeau (Jour. Agr. Prat., n. ser., 9 (1905), 

 No. 9, pp. 269, 270). — A brief general statement regarding the specific role of differ- 

 ent classes of soil organisms. 



Investigations of the bacterial content of cultivated and uncultivated 

 moor soils at Flahult, O. Fabrictus and H. von Feilitzen (Svenska Mosskulturfor. 

 Tidskr., 19 (1905), No. 2. pp. 84-90 ). — Chemical and bacteriological examinations of 

 6 types of moor soils that were of different origin or had received different mechan- 

 ical treatment were made at the moor culture station at Flahult, Sweden. 



The results show that the white-moor soils in their natural condition contain only 

 few bacteria, on account of the acid reaction of such soils. The bacterial flora is 

 only slightly changed by mere drainage, but is greatly increased by liming, admix- 

 ture with sand, manuring, and mechanical treatment, since the conditions for bac- 

 terial growth then become more favorable, and bacteria are moreover added in the 

 sand and manure. The total number of bacteria in the soil is closely related to the 

 soil temperature, and falls and rises with the latter. The number of bacteria on a 

 well manured and well cared for high-moor plantation appears to be about as high 

 as on a low-moor soil under similar physical conditions. — f. w. woll. 



Methods of bacteriological investigation of soils, II, F. Lohnis (Centbl. Bakt. 

 [etc.], 2. Alt., 14 (1905), No. 1, pp. 1-9; abs. in Chem. Centbl, 1905, 1, No. 10, p. 768).— 

 In continuation of previous work, the author studied the behavior of soil bacteria 

 under various conditions of medium and methods of culture. The behavior of the 

 organisms under different soil conditions is also discussed. 



The assimilation of atmospheric nitrogen by a peat mold, Charlotte 

 Ternetz (Ber. Deut. Bot. GeselL, 22 (1904), pp. 267-274; abs. in Centbl. Agr. Client., 

 34 (1905), No. 3, pp. 205, 206). 



Mutual action of plant food compounds in the soil on their assimilation 

 by plants, P. Kossovicir (Zhur. Opuitn. Agron. (Puss. Jour. Expl. Landw.), 5 

 (1904), No. 5, pp. 581-598).— The hypothesis of Prianishnikov and Shulov (E. S. R., 

 14, p. 851) attributes the greater availability of phosphoric acid in crude phosphates 

 in the presence of ammonium salts than in presence of nitrates to the fact that the 

 ammonium salts are physiologically acid, and thus aid in the solution of the insol- 

 uble phosphates. 



To further study this hypothesis the author made a series of experiments with 



