SOILS FERTILIZERS. 725 



Chem. Indus., 31 (1912), No. 20, p. 1000).— In continuation of previous experi- 

 ments (E. S. R., 26, p. 425) the author made comparative tests ou a variety of 

 crops of nepheline, muscovite, biotite, leucite, apophjilite. phillipsite, sauidine, 

 microcline, elaolith, and mica schist. 



The results show in general that while some of the alumino-silicates are 

 tolerably good sources of potash, others are worthless for this purpose. The 

 feldspar group is a poor source of potash for plants. The minerals tested ap- 

 peared to stand in the following order as regards availability of potash: Nephe- 

 line, mica, biotite, phillipsite, muscovite, eliiolith, leucite. apophyllite, sauidine, 

 orthoclase, microcline. This was practically the order indicated by the solu- 

 bility of the potash of the minerals in neutral salts (ammonium and barium 

 chlorids). 



To what extent can the potash of fine-ground feldspar be utilized by- 

 plants on moor soils? 11. von Feilitzen (Ernahr. Pflanzc, 8 (1012), A'o. 19, 

 PI). 225-232, figs. 6). — The results of the exi)eriments here reported, which ex- 

 tended over a series of years, indicated as a rule very little effect from the 

 potash of feldspar as compared with that of potash salts. 



Comparative tests of phonolite, 40 per cent potassium salts, and kainit, 

 M. Ohme (Deut. Landw. Prvssr, 39 (1912), No. 6',, pp. 7',0, 7^/i).— Plat experi- 

 ments on moor meadows during 1910 and 1911 indicated no beneficial results 

 from applications of phonolite, whereas the 40 per cent potassium salts and 

 kainit gave excellent returns. 



Thomas phosphate meal, I). J. IIissink (CuUitra, 2'f (1912), No. 288, pp. 

 315-317). — The requirements of the fertilizer law, as regards the composition, 

 solubility, and physical constitution of Tliomas meal as sold on the market in 

 the Netherlands, are stated and briefly exi)lained. 



The agricultural value of electric slag, M. de Molinari and O. Ligot (Ann. 

 Oembloiw, 22 (1912), No. 10, pp. 567-572, figs. 2; abs. in Engrais, 27 (1912), 

 No. Ifl, pp. 1138, 1139). — A brief account is given of pot experiments with oats 

 on sand and soil to determine the relative fertilizing value of ordinary Thomas 

 slag and slag made by a new electric process. The Thomas slag used con- 

 tained 21. SI per cent of phosphoric acid soluble in mineral acids and 20.94 per 

 cent soluble in 2 per cent citric acid. The two electric slags used contained, 

 respectively, 5.12 and G.76 per cent of phosphoric acid soluble in mineral acids 

 and 1.56 and 1.3S per cent soluble in 2 per cent citric acid. 



The results showed that on tlie basis of total phosphoric acid the electric slag 

 gave results inferior to those obtained with Thomas slag. On the basis of 

 phosphoric acid soluble in 2 per cent citric acid the results were about the same. 



The assimilation of phosphatic fertilizers in the course of a rotation, 

 A. MuNTz and H. Gaudixhon (Compt. Rend. Acad. Sci. [Paris], 155 (1912), 

 No. Ji, pp. 257-260; abs. in Rev. 8ci. [Paris], 50 (1912), II, No. 5, p. 156; Rev. 

 O^n. Agron., n. ser., 7 (1912), No. 8, pp. 289-292; Chem-. Zentbl., 1912, II, No. 

 15. p. 1307).— The general conclusion reached from these investigations is that 

 It is not advisable to apply large amounts of readily assimilable phosphatic 

 fertilizers, with the expectation that the effect of such fertilizers will be 

 extended over several years. On the contrary, the amount of such fertilizers 

 should be in proportion to the needs of the crops during each season. 



The assimilation of phosphoric acid by plants, A. MiJNTz and H. Gaudechon 

 (Ann. Sci. Agron., J,, ser., 1 (1912), II, No. 3, pp. 200-216; abs. in Jour. Soc. 

 Chem. Indus., SI (1912), No. 16, p. 787).— The rate of assimilation of phosphoric 

 acid by maize, wheat, barley, rape, turnips, mustard, beans, peas, and lupines 

 was determined in pot experiments with monocalcium phosphate (supei-phos- 

 phate), dicalcium phosphate (precipitated phosphate), and tricalcium phosphate. 



