622 EXPERIMENT STATION RECORD, 



On dicyandiamid bacteria, K. rEKorri {Ventbl. Jialct. [eic], 2. Abt., 21 

 {W08), Xo. 7-8, PI). 200-231). — The literature of inAestigatious on this subject 

 is reviewed, and an account' is given of the author's investigations on the activ- 

 ity of bacteria in culture Tiiedia containing dicyandiamid, isolation and deter- 

 mination of species growing in such media, the changes which the species bring 

 about in the media, comparison ol dicyandiamid with other sources of nitrogen 

 food for the organisms, and growth of field crops on media containing dicy- 

 andiamid. 



In media containing grape sugar and dicyandiamid (not exceeding 1 to 2 

 parts per 1,000) as the only source of nitrogen, there was a vigorous and char- 

 acteristic growth of micro-organisms, including various bacteria and fungi, some 

 new, others common forms. Certain of the forms apparently found the condi- 

 tions in dicyandiamid media moi-e favorable than others, but there was great 

 Aariation in the morjihology and cultural relations of the organisms which 

 utilized dicyandiamid as a source of nitrogen to best advantage. Some of these 

 organisms utilized other sources of nitrogen, particularly amids, as well as 

 dicyandiamiil. The activity of the organisms resulted in a slight decrease in 

 the percentage of dicyandiamid without a corresponding increase of ammonia. 

 Contrary to the statement of ITlpiani, the dicyandiamid did not undergo fer- 

 mentative action. 



The general conclusion drawn from this work is that dicyandiamid is a very 

 good nitrogen food for many micro-organisms. Higher plants grow about as 

 well in sterile media containing dicyandiamid as in those inoculated with dicy- 

 andiamid bacteria. 



The article concludes with a bibliography of o.j references to the literatui'c of 

 the subject. 



A review of the bacteriology of ammonium compounds, P. EHKENfeERO 

 {FiihJing's Lanchc. Ztg., 57 (1908), JVo. IS, pp. .'/.}9-.'/.5.5 ) . — The relation of micro- 

 organisms to the transformation and fixation of ammonia in soils is briefly 

 discussed. It is stated that experiments made by the author suggest that the 

 greater effectiveness of anunonium salts in experiments in zinc ])ots than in 

 experiments in the field may be due to the action of the zinc in interfering witJi 

 the activity of organisms which fix ammonia in the soil and thus decrease its 

 efficiency, the beneficial action of the zinc in this respect overbalancing its 

 direct injurious effect on the growth of the crop. 



The fixation of ammoniacal nitrogen by zeolites in soils, T. Pfeiffee, A. 

 llEPNEE. and I.. P^RANK {.Uitt. LaiKlir. In.st. Brc.sknt,J, (1008). Xo. 3, pp. 321-330: 

 ahs. in Chem. Ztf/., 32 (1908), Xo. 5.'i, Rcpert., p. 3.53; Zcntbl. Agr. Ghem., 37 

 (1908), Xo. 11, pp. 722-72li; ZtKichr. Aiigcic. Chem., 22 (1909), Xo. 5. p. 207).— 

 This is a second report on this subject (E. S. R., 17, p. .53G). A study of the 

 loss of nitrogen from soils fertilized with blood meal and ammonium sulphate, 

 with the addition in one series of pots of calcium carbonate and in another of 

 calcium zeolite, showed that where the zeolite was used there was a considerable 

 reduction in the loss of nitrogen from the soil, but that in the case of oats the 

 nitrogen so fixed was not utilized until the second crop, indicating that the 

 ammonia was too firndy fixed by the zeolite to be available in the course of 

 the first season. 



The action of ammoniacal nitrog'en under the influence of applications of 

 lime, T. Pfeiffer, A. Hepner, and L. Frank (Mitt. Laiidw. Inst. Breslau, If 

 (1908), Xo. 3, pp. 331-339; ahn. in Chem. Ztg., 32 (1908), No. 5.',, Rcpert., p. 

 .153). — In pot experiments it was found that on peat soils an application of 

 lime ytromoted the atcion of ammonium suli)hate. On pure sandy soils the 

 application of very large amounts of lime exerted an injurious effect upon 



