724 EXPERIMENT STATION RECORD, 



Peculiar plant physiological action of an ammonium fertilization, H. O. 

 SoDERBAUM {Meddcl. CentralanM. Forsoksv. Jordbruksomn^fict, No. 125 {1915), 

 pp. 13, figs. 2). — Pot experiments with barley on a sand soil are reported, in 

 which superphosphate, Thomas slag, and bone meal were used in different ex- 

 periments to supply phosphoric acid, while nitrogen was supplied as ammonium 

 chlorid and ammonium sulphate. The experiments were conducted with and 

 without additions of the sulphate or carbonate of magnesium. 



Two or three weeks after germination the plants in pots receiving super- 

 phosphate or bone meal and an ammonium salt, but no magnesium carbonate, 

 showed evidences of sickness and stunted growth. This was especially marked 

 in the pots receiving superphosphate. This effect was not observed in the pots 

 receiving Thomas slag, and additions of magnesium carbonate apparently re- 

 moved the condition. After such treatment the affected plants recovered and 

 rapidly reached normal development. 



These results are taken to indicate that the bad effect produced on the plants 

 is due less to the production of a physiologically acid reaction in the soil than 

 to a direct toxic action of the ammonium salts. The favorable action of mag- 

 nesium carbonate is explained on the grounds that the transformation of the 

 ammonia into nitrates is accelerated. 



Some observations on the storing of calcium cyanamid, A. H, Burgess and 

 I). K. Ki)Waki)Es-Kkk (Jour. Southcosf. Af/r. Col. Myc. No. 22 (WIS), pp. 363- 

 367; ahs. in Intcnwt. In-sit. Ar/r. [Rome], i[o. Bui. Agr. Intel, and Plant Z)i.<i- 

 cases, 6 (1915), No. 5. pp. 675, 676). — From the re.<;ults of a series of experi- 

 ments the authors conclude that loss of nitrogen from calcium cyanamid ex- 

 posed freely to the atmosphere is apparently not caused either by moisture or 

 carbon dioxid or by both acting together. When stored in air-tight containers 

 there is no loss of nitrogen and, therefore, the loss noted when exposed to 

 the air is probably caused by some atmospheric agent. A fall in the percentage 

 of nitrogen, owing to the increase of weight, is caused by the absorption of 

 Avater, but water does not cause any real loss of nitrogen. 



The world's supply of potash (London: The Imperinl Institute, 1915, pp. ^7; 

 ahs. in Ndturr. [London], 96 (1915), No. 239^, pp. 60. 61). — This pamphlet con- 

 tains an account of the more important sources of potash in the world, including 

 the Stassfurt deposits in Germany. 



It is stated that besides the Stassfurt deposits, the only extensive deposit of 

 carnallite known is that at Catalonia, in Spain. "All plants contain more or 

 less potash, and the utilization of the ash of wood, the ash of seaweed, of beet- 

 root residues, and similar by-products of industries in which vegetable materials 

 are employed, is of importance, . . . especially at a time of scarcity." The ashes 

 of seaweed, waste wood, hedge trlnunings, and vegetable refuse, and the waste 

 water from the wool-scoiu'ing process are also discussed as promising sources 

 of potash. 



The origin, mining, and preparation of phosphate rock. E. H. Sellakds 

 (Trans. Amer. Inst. Mining Kngin., 50 (1914), pp. 901-916. figs. .9).— This is a 

 summary of information on the subject, referring especially to the Florida and 

 Tennessee phosphate deposits. 



Tennessee phosphate practice, J. A. Barb (Trans. Atner. Inst. Mining Engin., 

 ,'iO (1914), pp. 917-933, figs. 12). — This article briefly describes the geology and 

 mineralogy of the Tennessee phosphate deposits and the methods employed in 

 prospecting, valuation, mining, and treatment, and in the manufacture of 

 acid phosphate.. 



Sensitiveness of lupines to calcium, T. Pf-etffeb and E. Bi.anck (Mitt. 

 Landio. Inst. Brestau, 7 (1914), No. 2, pp. 201-233: abs. in ZenthJ. Agr. Chem., 

 U (1915), No. 1, pp. 22-25; Jour. Chctn. ^oc. [London]. lOS (1915). No. 630, I, 



