SOILS FERTILIZERS. 821 



12, pp. 501-520; ahs. in Jour. Soc. Chem. Indus., 34 {1015), No. 18, p. 912).— 

 Experiments are reported, the results of which are taken to indicate that the 

 red coloration given by certain kinds of Thomas slag when decomposed with 

 strong sulphuric acid is due to the presence of trivalent manganese, mainly in 

 the form of a mangani-phosphoric acid compound. The color was also given 

 by other kinds of basic slag to which potassium permanganate was added. By 

 properly varying the conditions of temperature and oxidation it was possible 

 to obtain, from the slag leaving the converter, a product giving a green-blue 

 or red coloration with sulphuric acid. The oxidation of manganous oxid iu 

 slag, ijt is thought, can be promoted under certain conditions by the presence 

 of free lime. It is considered probable that the proportion of ferrous oxid to 

 manganese in the slag also has an influence on the formation of a compound 

 giving a red coloration with sulphuric acid. 



The pebble phosphates of Florida, E. H. Sellaeds {Fla. Oeol. Survey Ann. 

 Rpt., 7 (1914), pp. 25-116, pi. 1, figs. 5i).— This paper deals in detail with the 

 origin, location, and conditions of deposition of the land and river pebble de- 

 posits of Florida. 



Possible sources of potash in America, F. K. Camekon {Jour. Franklin Inst, 

 180 (1915), No. 6, pp. 641-651; Amer. Fert., 44 (1916), No. 2, pp. 21-26; Sci. 

 Amcr. Sup., 81 (1916), No. 2089, pp. 34, 35).— This is a discussion of desert 

 basins, alunite, and kelp as possible sources of potash in America. It is con- 

 cluded that " there are within the United States large stores of raw materials 

 from which it is possible to obtain ample supplies of potash salts ; that the 

 technology of the subject is sufficiently developed to demonstrate the entire 

 practicability of a supply from native sources, so far as physical factors are 

 concerned." 



Statistical potash fertilizer experiments in 1914, with special reference to 

 top-dressings and meadow fertilization, M. Hoffmann (Mitt. Deut. Lnndio. 

 Gescll., 30 (1915), No. 38, pp. 560-566). — A classified review of a number of ex- 

 periments along this line is given. 



The importance of fineness of subdivision to the utility of cinished lime- 

 stone as a soil amendment, W. Thomas and W. Freak (Jour. Indus, and 

 Engin. Chem., 7 (1915), No. 12, pp. IO41, 1042).— Th^ substance of this article 

 has been noted from another source (E. S. R., 34, p. 133). 



The lime mag'nesia ratio in soil amendments, W. Thomas and W. Fbeab 

 (Jour. Indus, and Engin. CJiem., 7 (1915), No. 12, pp. IO42-IO44).— The sub- 

 stance of this article has been noted from another source (E. S. R., 34, p. 133). 



The effects of radio-active ores and residues on plant life, M. H. F. Sutton 

 (Reading, Eng.: Sutton tC- Sons, 1914, Bui. 6, pp. 15, figs. 4)- — Box and labora- 

 tory experiments, described previously in a brief note by Bastin (E. S. R., 33, 

 p. 123), to determine the influence of two radio-active ores containing, respec- 

 tively, 8 and 9 mg. of radium bromid per ton, of radium mine residue containing 

 the equivalent of 1.8 mg. of radium bromid per ton, and of black oxid of 

 uranium, on the growth of radishes, lettuce, peas, tall nastui'tiums, and flower- 

 ing annuals, and on the germination of red clover, smooth stalked meadow 

 grass, and rape, are reported in detail. The radio-active ores were added to 

 the vegetables at rates of from 1 part of ore to 12 parts of soil, to 1 part of 

 ore to 48 parts of soil, and to tall nasturtiums at rates of from 1 : 14 to 1 : 2,240 

 parts of soil. The radium residue was added to nasturtiums at the same rates 

 as the ore. Black oxid was added to the flowering annuals at the rate of 1 

 part to 2,000 parts of soil. 



The results obtained " afford some evidence that radium emanations possess 

 the property of developing and increasing growth. Many of the radish, lettuce, 



