1020 EXPERIMENT STATION EECORD. 



aiiiiiKiniuni siilpliale, blood, niul roasted leather are reported, showing that 

 takiui,' the rate of nit.rilicalioii of sulphate of ammonia during 5 months as 100, 

 that of calcium cyanamid was 88, dried blood GG, and roasted leatlier 26. When 

 as in these experiments the cyanamid was employed in amounts 10 to 20 times 

 greater than those ordinarily used in practice, the nitrifying organisms were 

 paralyzed at first and even a small amount of denitriticatiou occurred, but in a 

 sliort time the organisms ai)parently adapted tliemselves to the medium and 

 normal uitriticatiou was restored. This retardation is due to the cyanamid 

 and not to the excess of caustic lime present. Amounts of the material fur- 

 nishing 35.7 lbs. of nitrogen per acre may be applied without any retardation of 

 nitrification. Very large amounts may be applied to humus soils in a very 

 active state of uitrilication without retarding this process, and still larger 

 amounts may be used ((iO times that employed in intensive culture) if added in 

 successive applicati»)ns extending over a considerable period (4 uumths). 



Comparative held tests on different kinds of soil confirm in general the la'jor- 

 atory results. In only one case were unfavoi-able results obtain.e<l in the ai)pli- 

 cation of the cyanamid at the time of planting. Nevertheless, as a precautionary 

 measure it is advised to apply the material shortly in advance of planting. The 

 cysmaniid was applied in amounts furnishing 35.7 lbs. of nitrogen per acre in 

 March and April on wheat and oats, and in amounts furnishing 41.05 lbs. of 

 nitrogen per acre on grapes and natural grass lands. In damp weather there 

 was no injury from such application. In dry weather the grain and grass were 

 slightly burned, but soon recovered from the bad effects and the linal yield was 

 not reduced. The authors advise, however, that the cyanamid should not be 

 {'.pplied as a top-dressing except in wet weather. 



The genei-al conclusion from these investigations is that calcium cyanamid 

 is substantially analogous to sulphate of ammonia as a fertilizer. 



On the decomposition of lime nitrogen in soils, H. Imjiendokff {t'lion. Zt<i., 

 32 (W08), jS'o. 80, ijp. 071, D72; Umschau, 12 {1908), Ao. //-J, pi). 87Jf-876; Osterr. 

 Chem. Ztff., 11 (1908), No. 23, pp. 315, 316). — Investigations on this sub.1ect are 

 reviewed. 



Physiolog'ical action of dicyandiamid, O. Loew {Chcm. Ztg., 32 (1908), 

 Ao. .57, pp. 676, 677; abs. in Jour. Chem. Sac. [London], 9Jf {1908), Ao. 551, II, 

 p. 775; Chem. Abs., 3 {1909), No.'2, p. 221). — Observations are reported which 

 led to the conclusion that dicyandiamid is not a good source of nitrogen for 

 many kinds of soil bacteria, the growth being much less rapid in media con- 

 taining small amounts of this substance than in those containing ammouiTuu 

 sulphate. 



When young barley plants were placed in a 5 per cent solution of the sub- 

 stance an injurious effect was noticed after 2 days. Lathyrus plants withstood 

 the injurious action of dicyandiamid somewhat longer. With 0.05 to 0.1 per 

 cent solutions only the points of the leaves were affected. Twigs of Trades- 

 cantia in 0.1 per cent solution and Elodea in 0.2 per cent solution showed no 

 injurious effects, and Elodea apparently utilized the dicyandiamid as a source 

 of nitrogen. Threads of Si)irogyra remained intact for several days in 1 per 

 cent solutions of dicyandiamid, and worms lived for more than 4 days in 0.5 

 per centx solution. Bacteria were not injured in the least in broth containing 

 0.5 per cent of the substance. 



The structural fornnila of the dicyandiamid is discussed. 



The ipiportance of nitrogen, H. Steinmetz {Bcr. Xaturw. Ter. Regensburg, 

 1905-6, Ao. 11, pp. 108-119). — The importance of nitrogen in relation to industry 

 and plant and animal life, and the possibilities of developing the manufacture of 



