1920] SOILS — FERTILIZERS. 519 



67 {l'JJ9), Xo. 3, pp. 171-17(1 flfj. 1). — Kxpcrlniental results aro roi)orto(l, and 

 an intricate niatlieniatioal discussion is ^iven in an aiM'ii'-ently uns\iccesslul 

 effort to establisii a defnute law showing the relation between the content of 

 the oats plant in phosphoric acid and fertilization as a means for determining 

 the absolute phosphate requirement of soil. 



Field tests on tlie action of fertilizers on soil aldehydes, J. J. Skinneu 

 and ('. F. Xoi.r, {rcnnsiilyiniia Sta. Ix'pl. 1U1G, pp. 69-85, pis. 8, fig. i).— This 

 arliclo has h(>en prevlnusly uoIimI from another source (E. S. R., 30, p. 424). 



Separation of dust from lime nitrogen, N. Cabo {CJicm. Ztfj-, ^i^f (1920), No. 

 8, pp. JJ-.-76"; (ilhs. in -lour. t<0(: Vhcm. Indus., 39 {1920), Xo. 5, pp. 200A, 201 A).— 

 Different methods for reducing the dustiness of lime nitrogen to a mininmm 

 are discussed, it being concluded that treatment with a neutral oil has given 

 the best results. On account of the high cost of such treatment and the fact 

 tiiat the causticity of the lime nitrogen is not affected, it is considered desirable 

 tolind .«;ome treatment which will neutralize the caustic action without reducing 

 the fertilizing value of the lime nitrogen. 



Improvement of lime nitrogen, J. Baumann (Chcm. Ztfl., J^'t {1920), No. 

 23. pp. 1,')8, 159). — Some of the disadvantages of crude calcium cyanamid as a 

 f(Mtilizer are reviewed, anrl it is proposed to obtain the nitrogen of this fer- 

 tilizer in a more suitable form liy combining the cyanamid and amnumia-soda 

 processes. The anunonia for the process is to be obtained from calcium cyana- 

 mid, and the liquors from the sodium bicarlx>nate, which contain ammonium 

 ciilorid and sodium chlorid, are to ^e evaporated to crystallize out the am- 

 monium chlorid. The ammonia is thus recovered as chlorid for use as a fer- 

 tilizer, and the lime which would have been used for regeneration of the 

 anunoHKi is used for the manufacture of cyanamid. It is estimated that con- 

 siderable sjiving can be effected by the proposed combination of the two 

 processes. Alternate processes are also suggested. 



Lime nitrogen as a top-dressing, J. Kuhn (Deut. Landic. Prcsse, 47 {1920), 

 Kos. 5, p. 35; 6, pp. 42, Jf3 ; 7, pp. 50, 51). — Experiments to determine the possi- 

 bility of using lim'e nitrogen as a top-dressing are reviewed and summarized. 



The largest practical applications were relatively small. Frequently larger 

 applications were found not to be injurious, but a warning is sounded against 

 such applications in practice because there was considerable variation in the 

 Injurious action of the lime nitrogen in individual cases. Such injurious action 

 was closely related to the content of dicyandiamid. 



The national aspects of the case for increasing the supplies of basic 

 slag, T. MiDULETON {Jour. Min. Agr. [London], 27 {1920), No. 3, pp. 2.}i-2//.9).— 

 The value of basic slag as a means of. improving pastures, thus increasing 

 meat production and at the same time making it possible to increase the tilled 

 area in case of a national emergency, is especially emphasized in this article. 



The separation of feldspar for the technical production of potash, B. 

 Nkumann and F. Dkaisbach {Ztschr. Angev. Chrni., 29 {1916), Nos. 65, 

 Auf.mtz., pp. 313. 319; 67, pp. 326-331, figs. 3).— The authors describe the dif- 

 ferent American sources of potash and give a list of proce.s.ses for the separation 

 of potash front feldspar. 



> Tests of a number of the different processes are reported, leading to the 

 conclusion that better results are produced by roasting than by treatment in the 

 autoclave. In the roasting experiments the best results were obtained by the 

 use of lime and magnesium chlorid or calcium chlorid. The latter treatment 

 especially resulted in a complete separation of the potash from the feldspar. 



The use of lime on the soil, E. O. Fippin {Cornell Reading Course for the 

 Farm No. U8 {1919), pp. 31-92, figs. .?6).— This is a popular bulletin based on 



BW York conditions, the main purposes of which are " to explain some of the 



JiSYI 



