SOILS FERTILIZERS. 525 



sodium clilorid aud sodium sulphate, only dissolves the nitrate. When the 

 insoluble matter has subsided, the clear liquor is run into wooden vats, and on 

 cooling deposits a good deal of potassium nitrate, that only requires to be 

 drained and slightly washed to be ready for market. The insoluble material 

 still contains some potassium nitrate, and is thrown out on to the factory heap 

 of niter earth, from which more nitrate is subsequently again extracted as 

 before. The mother liquor can not be used indefinitely for the purification of 

 the crude saltpeter, but it is not wasted. When it becomes too impure for 

 further use, it is concentrated to deposit some of the sodium chlorid, and the 

 final liquor is simply thrown on to the factory heap again. While the extrac- 

 tion process is remarkably efficient, considering that it has been evolved by the 

 natives themselves without outside help, the refinery process is admittedly 

 wasteful." 



A product containing as high as 96 per cent of potassium nitrate is obtained 

 by the processes described, the principal impurities being sodium and potassium 

 chlorids and sulphates. The principal by-product is common salt. 



Anim.onia evaporation and transformation in soils, J. von Wlodeck (Diss. 

 Berlin, 1911, pp. 88; ais. in Zenthl. Agr. Chem., 40 (1911), No. 11, pp. 729-734; 

 CcntU. Bakt. [etc.], 2. AM., 82 {1912), No. 6-12, p. 270; Jour. Chem. Soc. 

 [London], 102 (1912), No. 591, II, pp. 85, 86).— The lower fertilizing efficiency 

 of ammonium sulphate as compared with sodium nitrate has been ascribed to 

 various causes including slowness of nitrification, fixation of nitrogen in or- 

 ganic forms, and evaporation of ammonia. The author reviews work of other 

 investigators on the subject, and reports experiments on soils in sunken cylin- 

 ders to determine the loss and transformation of ammonia from soils contain- 

 ing varying amounts of lime, silt, and clay, and with vai-yiog applications of 

 ammonium sulphate, either alone or in combination with superphosphate. 



The loss of ammonia by evaporation, when the ammonium sulphate was used 

 under conditions as nearly natural as possible, was very small. With a high 

 lime content of the soil and heavy applications of ammonium sulphate the loss 

 was larger. There was little or no loss when a mixture of ammonium sulphate 

 and superphosphate was used. Deep applications of the ammonium sulphate 

 greatly reduced loss of ammonia. 



The results of observations on fixation of the ammonia in organic forms were 

 not entirely conclusive, but indicated that fixation in case of a loam soil was 

 practically the same whether the ammonium sulphate was used alone or mixed 

 with superphosphate. On a light soil, however, the superphosphate appeared 

 to increase nitrogen fixation. The addition of supeiT)bosphate apparently did 

 not affect nitrification. 



Lime nitrogen and lime niter as nitrogenous fertilizers, B. Heinze (Jahres- 

 ber. Ver. Angew. Bot., 8 (1910), pp. 79-94, ZZ-ZZ//).— This article briefly de- 

 scribes the preparation and properties of calcium cyanamid and calcium ni- 

 trate, and discusses their value and behavior as nitrogenous fertilizers (E. S. It.. 

 22, p. 621). Pot experiments with these materials in comparison with other 

 nitrogenous substances are referred to, the most important new conclusions 

 reached being that while ammonia is quickly formed from calcium cyanamid 

 in the soil it is slowly converted into nitrates, and that "the ammonia is formed, 

 in part at least, by purely chemical processes. 



The hygroscopicity of certain new nitrogenous fertilizers, H. von Feilitzen 

 and I. Lugner (Chem. Ztg., 35 (1911), No. 108, pp. 985, 986, figs. 2).— These 

 investigations have already been noted from another source (E. S. E., 25, p. 

 727). 



[Experiments with potash fertilizers in Pas-de-Calais], L. Malpeaux 

 (Jour. Agr. Prat., n. scr., 22 (1911), No. 50, pp. 754-757). — In experiments car- 



