SOILS FERTILIZEKS. 725 



jiiiy case it slioiild lu' well worked into the soil, that it may have as much mois- 

 ture as |iossil)!e. 



On the nitrification of calcium cyanamid in various types of soil, S. de 

 (Jkazia (Stdz. Spcr. Af/r. Itiil., '/I ilHOS), Xo. .7-6', /)/). .l'it-.i.')~i ; nh><. in Chrm. 

 /.(■'ithl.. I'.iiis. II. A o. 12. i>. lOtUI). — This is a report of pot exi)eriments on tiie 

 nitritication of calcium cyanamid compared with sulphate of ammonia in sandy, 

 clayey, huunis, and calcareous soils. The results obtained are summarized as 

 follows : 



The nitritication of calcium cyanamid differs from that of snl])hate of am- 

 monia chielly in the fact that until decomposition hej^ins the cyanamid has a 

 harmful eft'ect on the micro-organisms of the soil. This is shown less in slow- 

 ness of the action than in delay of its be^iinnin^. 



This specific behavior of calcium cyanamid can not bt> considered as inakinji 

 it inferior to sulphate of ammonia, since no harm can result when the fertilizer 

 is applied befoi'e the sowing. 



The nitrification of calcium cyanamid begins and is completed much more 

 rai)idly in .soils rich in organic material (nonacid) and in clayey soils than in 

 sandy and limy soils. 



Such marked influence of the nature of the soil probably depends on the 

 degi-ee of fermentation and especially on the absorptive capacity of each type 



nf soil. 



Absorption of calcium cyanamid in soil, II. Kaitkn {L<iiulic. Vrr.s-. Slat.. 

 (18 {1908). No. 5-6, pp. 301-331; abs. in Jour. Chcm. Soe. [London], 9', (1908), 

 \». .-,.-,(/. II. p. 7J8; Chcm. ZcntbL, 1!W8, II, No. 0, pp. 818, 819; Chrm. Abft.. 3 

 t 1909). .\». 3. p. 351). — From experiments with different kinds of soil the 

 author concludes that the absori)tive power of soils causes a decomiiosition 

 of calcium cyanamid ir.to lime, which is readily absorbed, and cyanamid. which 

 is less readily absorbed. Cyanamid is also produced by carbon dioxid, and 

 when these two agencies operate at the same time the production of free 

 cyanamid is very rapid. This pnMluction of cyanamid produces a favorable 

 f'ff«H-t on the growth of i)lants because the fi'ee cyanamid is more easily at- 

 tacked by bacteria than the alkaline calcium cyanamid. In soils of low absorp- 

 tive power tlie transformation of calcium cyanamid is slower and under these 

 conditions germination and growth of plants may be injuriously affected by the 

 und»H-omposed cyanamid conipoimds. The influence of absorption on the 

 pois<inous action of calcium cyanamid is then'fore indirect and due to the fact 

 that conditions favorable to the rapid conversion of poisonous coni]K)nnds info 

 hannless substances are thereby prtMlucetl. 



Experiments with calcium cyanamid and leucite as fertilizers for wheat 

 and beans, I. Hanuini (.1//i R. Avcad. Evnn. A{/r. (leonj. Fircmr. ■'>. ><<i:. 

 (1908), \o. 3. pp. 267-^75). — The I'esults of the plat experiments reportwl 

 --liow that the cyanamid was inferior to nitrate of soda as a fertilizer for 

 wIkmi. hi exiieriments with beans, leu«-ite coml)ined with mineral phosphate 

 gave a larger crop and gre.iter net reluiii th.-in pot.issinm clilorid s<i combined. 



On the causes that determine the liberation of potash in leucite in culti- 



ated soil. L. Hkrnakoi.m ( .s7'/~. Spn: Agr. ItaL. ',1 {1908). Xo. .',-i;. pp. 

 "I'l 320). — In central and southern Italy leucite occurs frequently and (piite 

 abundantly in .soils of volcanic origin, and this study was underl.iken to deter- 

 nuue the |»osKibility of utilizing leucite as a source of potash. 



The autlior found that leucite yields its imtash when shaken with solutions 

 of s(Hlium and .immonium salts. This action is a chemical phenomenon due to 

 .1 reaction between the insoluble unneral and the salt in solution resulting in 

 a double exchange of base's. This reaction in the case of ammonium salts is 

 of imiHjrtauce in relation to the process of ummouilicutiou of the organic sub- 



