84 SOIL SCIENCE [BoT. Absts., Vol. IX, 



544. JuRiTZ, C. F. Calcium cyanamide. Its agricultural use as a fertilizer. Jour. Dept. 

 Agric. Union of South Africa 1: 765-769. 1920. — A review of experiments with cyanamide is 

 given. Under certain conditions of storage, dicyanamide is formed which is harmful to plants ; 

 its poisonous action is discussed. From the experiments cited the productive value of cyana- 

 mide is lower than that of nitrate of soda or sulphate of ammonia. — J . J . Skinner. , 



545. Kellet, W. p., and A. B. Cummins. Chemical effect of salts on soils. Soil Sci. 

 11: 139-159. Fig. 1-7. 1921. — A comparison was made between the analyses of the filtrate 

 from a given soil after being treated with distilled water or with solutions of various salts. 

 Chemically equivalent solutions of the chlorides, sulphates, and nitrates of a given base pro- 

 duced substantially equivalent chemical reactions in the soils studied. An exchange of bases 

 took place with the result that a portion of the base of the added salt passed out of solution 

 and a chemically equivalent amount of other bases was set free from the soil silicates; calcium 

 is the base most easily replaced in the soils used. Considerable amounts of phosphate were 

 precipitated by the soils. The reactions between neutral salts and soils are dependent upon 

 the concentration and apparently obey the principle of mass action. — W . J . Bobbins. 



546. LiPMAN, J. G. New Jersey's experience with fertilizers. Potato Mag. 3^: 7, 28, 30. 

 1 fig. 1921. 



547. LiPMAN, J. G., A. W. Blair, W. H. Martin, and C. S. Beckwith. Inoculated sul- 

 fur as a plant-food solvent. Soil Sci. 11 : 87-92. 1921. — The crop yields on field plots to which 

 inoculated or uninoculated sulphur alone or with greensand marl or rock phosphate were 

 added indicate that inoculated sulphur is more effective in rendering inert mineral plant food 

 accessible to growing crops than uninoculated sulphur. — W. J. Robbins. 



548. Marchand, B. de C. Representative Transvaal soils. The Koedoespoort red loam. 

 I. Jour. Dept. Agric. Union of South Africa 1: 722-727. 1920. — Fertilizer experiments show 

 that this soil is improved by the addition of phosphates, especially basic slag. Potash and 

 nitrogen do not increase the productivity of the soil. Chemical analyses of a number of samp- 

 les are given and show the soil to be rich in iron and alummum. — J. J. Skinnei . 



549. Maschhaupt, J. G. De invloed van grondsoort en bemesting op het gehalte onzer 

 landbouwgewassen aan stikstof en aschbestanddeelen VII. [The influence of kind of soil 

 and fertilizer upon nitrogen and ash content of agricultural crops VII.] Verslag. Landbouwk. 

 Onderzoek. Rijkslandbouwproefsta. 23:40-56. 1919. 



550. Osbon, C. C. Peat in the Dismal Swamp, Virginia and North Carolina. U. S. Geol. 

 Surv. Bull. 7ir: 41-59. S pi. 1919. — The Dismal Swamp covers approximately 2,200 square 

 miles, of which a little more then 700 have been drained to a depth of 3 feet or more by the 

 Dismal Swamp Canal and smaller ditches. Much of the drained land is farmed. In the 

 remaining 1500 square miles peat deposits ranging in depth from 1 to 20 feet are found. The 

 thickest beds lie in the region east and northeast of Lake Drummond, where peat 18 feet 

 deep was exposed by comparatively recent excavations. The peat in this area is black and 

 low in inorganic impurities and is probably the best in the swamp. In general, the depth 

 of the peat gradually decreases toward the edge of the swamp, where the peat finally merges 

 into the sands of the adjoining areas. It is estimated that the average thickness of the peat 

 is 7 feet and the total available peat in the Dismal Swamp 672,000,000 tons. The peat deposits 

 lie in shallow basins that originated in an extensive depression of the Columbia group of 

 formations. — J. J. Skinner. 



551. Scheringa, K. Is chemische denitrificatie van belang voor den landbouw en voor 

 het water onderzoek? [Is chemical denitrification important for agriculture and the examina- 

 tion of water?] Pharm. Weekbl. 57: 1481-1483. 1920.— Some nitrogenous substances, such 

 as the diazo compounds, easily give off nitrogen on account of the indifferent properties of 

 the latter. Some years ago Marpmann claimed that nitrogen can be liberated from nitroge- 



