1118 KXPKHIMKNT STATION JJKCOHI). 



liiiii of lime nitroficii, tlio fornuitioii and dt'c-oniijosilioii of dk-yaiuliauiid, and 

 the relation of bacteria to the doconiposition of lime nitrogen. 



The authors conclude from their investigations that the decomposition of 

 lime nitrogen in the soil takes place in the following way: Ky solution the 

 calciuin cyananiid is converted into calcium dicyandiainid K'N.NII )i..C'a. On 

 standing of the solution, or more quickly under the influence of heat or the 

 absorptive power of the soil iiarticles, the lime of the cyananiid is set free. The 

 cyanamid under the action of weak acids (carbon dioxid) or heating in the 

 jiresence of basic substances (caustic lime) is converted into ammonium cyanate 

 and finally into urea, the latter being converted into ammonium carbonate by 

 the action of bacteria. 



As Ulpiani found, there is no direct bacterial action on cyanamid. Bacteria 

 do not attack dicyandiamid either in dilute or concentrated solution. In ex- 

 periments on the decomposition of lime nitrogen in which soil is used it makes 

 no difference whether the solution is heated or not. 



Is dicyandiamid a poison for field crops? O. Loew (Chcm. Ztg., 33 {1909). 

 No. 3, pp. 21, 22; ahs. in Jour. Chem. Soc. [London], 96 (1909), No. 556, II, 

 p. 177; Chcm. Zentbl. 1909, I, No. 9, p. 785; Chem. Abs., 3 {1909), No. 10, 

 p. 1197). — ^Pot experiments with barley on humus garden soil, comparing dicy- 

 andiamid (0.75 gm. to 3.5 kg. of soil) on sterilized and unsterilized soil, am- 

 monium sulphate, and no nitrogenous fertilizer, are reported. 



The results showed that on sterilized soil dicyandiamid gave the same yield 

 as ammonium sulphate. On unsterilized soil the growth of the plants was seri- 

 ously interfered with as a result, in the autlior's opinion, of the formation of 

 injurious compounds from the dicyandiamid through the action of the bacteria. 

 It was noticed in the case both of sterilized and unsterilized soil that the use of 

 dicyandiamid resulted in a drying up of the tips of the leaves of the barley, a 

 result attributed to the excessive accumulation of the dicyandiamid in that part 

 of the plant. 



The structural formula of the dicyandiamid is discussed. 



An observation on calcium, cyanamid, J. Aebv (Chcm. Ztg., 33 {1909), No. 

 17, p. l-',5; fl&.s. in Ztschr. Angcio. Chcm.. 22 (1909). No. 15, p. 687).— It is re- 

 ported that a loss of 1.1 per cent due to the formation of acetylene was observed 

 in a lot of calcium cj'anamid left exposed to damp air on the wharves at 

 Antwerp. This is attributed to excess of calcium carbid in the material result- 

 ing from imperfect methods of manufacture, and it is suggested that a guaranty 

 of the content of this substance should be required in case of calcium cyanamid 

 intended for extended transportation. 



The assimilation of potash, by plants, AY. IvRiTGER {Ztschr. Vcr. Dcut. 

 Zuckcrindiis., 1908, No. 631. II, p/). 739-750; Jahrb. Dent. Landic. GchcU., 23 

 (1908), No. -',, pp. 633-649; abs. in Chcm. Abs., 3 {1909), No. 3, p. 350).— Fer- 

 tilizer experiments with sugar beets, rye grass, chicory, barley, rye, peas, pota- 

 toes, and other plants are reported, and the factors influencing the assimilation 

 of potash are discussed. These are variety of plant, character and quality of 

 soil, fertilizer, weather, etc., and the micro-organisms of the soil. Attention 

 is called to the importance of the return of fertilizing constituents from the 

 plant to the soil during the period of growth. The effect of good fertilization 

 in offsetting injury from nematodes is emphasized. Lack of potash in the cul- 

 ture of sugai' beets was not shown until the reserve of potash in the root had 

 been consumed, when further development was chec-ked. 



Phonolith, so-called potash silicate, as a fertilizer, P. Wagner (Mitt. Deut. 

 Landiv. Gesell., 2.'f {1909), No. 2. pp. 19, 20). — Comparative tests of this ma- 

 terial and of sulphate of potash on grass and tomatoes on sandy soils are re- 

 ported, the results showing that the rock meal furnished so little assimilable 



