SOILS FERTILIZERS. 121 



maximum in the fall. In general a certain parallelism appeared to exist be- 

 tween bacterial numbers and the i^ower to assimilate nitrogen. 



The optimum temperature for nitrogen fixing bacteria varied with the sea- 

 sons but somewhat slowly. Temperature variation during the day exerted no 

 influence. Studies of other biological processes produced no conclusive results. 



Isolation of Bacillus radicicola from soil, C. B. Lipman and L. W. Fowler 

 (Science, n. ser., 41 (1915), No. 1050, pp. 256-259) .—The methods used with 

 success for the isolation of B. radicicola directly from the soil are described, 

 and it is shown that the organism so obtained " at least in some forms and 

 places can be readily made to grow on agar plates in large numbers," thus in- 

 dicating the desirability of using soil extract-maltose agar for this purpose. 

 The latter was prepared by dissolving 15 gm. of agar and 10 gm. of maltose in 

 a soil extract, of the proper dilution, prepared by shaking 30 gm. of soil for 

 15 minutes in a sterile bottle with 150 cc of sterile water. 



The origin of the " niter spots " in certain western soils, R. Stewart and 

 W. Peterson (Jour. Amer. Soc. Agron., 6 (1914), No. 6, pp. 241-248). — Investi- 

 gations reported more fully elsewhere (E. S. R., 32, p. 28) are cited to show 

 " that (1) the nitrates of the ' niter spots ' are derived by concentration from the 

 original rocks contributing to the soil formation, and that (2) the color of 

 these spots is the direct result of the solvent and decomposing action of the 

 sodium or potassium nitrate uixtn the organic matter of the soil." 



The soils of the western New York fruit and grain region, E. O. Fippin 

 (Cornell Countryman, 12 (1915), No. 5, pp. 368-374, figs. 3).— This article 

 deals with the characteristics, crop adaptabilities, and fertility requirements 

 of the soils of an area in New York lying adjacent to Lakes Erie and Ontario 

 on the south side. 



The natural drainage of the area is poorly developed and the topography is 

 very diverse, varying from flat to undulating. The soils range from heavy 

 stratified clay to loose sand and gravel and are divided into seven series, two 

 of which are of glacial origin, four of lake and swamp derivation, and one of 

 recent alluvial origin. The Ontario series is the most extensively developed 

 in the region. The prevailing soil is a heavy loam to a clay loam. There are 

 extensive areas of silt loam and several small areas of drifting sand, and gravel 

 deposits are widely distributed. "A large part of the land is notably cal- 

 careous, especially in the subsoil. ... In general the stock of organic matter 

 is fairly good but requires attention." 



The sandy soil of Sylvan Beach, ITew York, N. Knight (Chem. News, 111 

 (1915), No. 2879, p. 49)- — Analyses of a sandy soil on the eastern shore of 

 Oneida Lake which shows marked oxidizing powers disclosed the presence of 

 much less iron than was expected. The free access of air is thought to be the 

 main reason for the rapid oxidation of organic matter. It is also thought that 

 by the free use of organic manures a fairly rich and productive soil may be 

 formed. 



Salts in soils and waters of the south coast of Porto Rico, J. T. Ceawlet 

 (Porto Ri^o Bd. Agr. Expt. 8ta. Bui. 9 (1915), pp. 25). — Continuing work by 

 Zerban (E. S. R., 29, p. 513), this bulletin reports studies of the chemical 

 composition of the soils and irrigation waters of the locality. One of the pur- 

 poses of the investigation was to show a connection between the existence of 

 so-called " salt spots " and the noticeable deterioration of cane. 



The results show that the salt spots and areas affected by salts are widely 

 distributed and of considerable total extent. " In some cases the salt areas 

 are increasing in size and encroaching on the cane areas, while in other cases 

 they are diminishing, and the cane areas extending. The prevalent salts are 

 the bicarbonates, chlorids, and sulphates, and of these the bicarbonates are 



