SOILS. 19 



Report on the clays of Maryland, II. Ries {Maryland Geol. Survey, 4 {1902), 

 ]jp. M5-.505, pis. 51, Jigs. :]0). 



On the plasticity of clay, P. Rohland {Ztschr. Aituryan. Cliem., 31 {190:^), No. 

 1, pp. 158-160). — The plasticity of clay is ascril^ed to the constituents which form 

 colloidal solutions with water. 



Mineral in Jamaica soils, E. Leuscher {Ztschr. Oeffentl. Chem., 8 {1902), )>/). 

 28, 29). — An exauaination of black balls found in the clay soils and subsoils of 

 Jamaica are reported, which show them to contain 14.75 per cent of manganese 

 and 13.6 per cent of iron. 



The Jurassic region of Belgium, A. Henry {Jour. Soc. Cent. Ayr. Behj., 49 

 {1902) , Nos. 2, pp. 90, 91; 3, pp. 120-122). — This is a brief account of the geological, 

 soil, climatic, and agricultural conditions of this region. 



The nature, value, and utilization of alkali lands, E. W. Hilgard {Ayr. 

 Ledger, 1901, No. 4 {Min. and Met. Ser., No. 17), pp. 41-69). — This is a review of 

 California Station Bulletin 128 (E. S. R., 12, p. 221). 



The effect of lime on the insoluble phosphates of the soil, W. F. Sutherst 

 {Chem. News, 85 {1902), No. 2210, p. 157; Ayr. Gaz. ILondoii], 55 {1902), No. 1474, 

 p. 204)- — By mixing various iron and aluminium phosphates with twice their weight 

 of slaked lime in the presence of water the following results were obtained: Proto- 

 phosphate of iron, which originally contained only 2.47 per cent of phosphoric acid 

 soluble in citric acid by Dyer's method, showed 19.55 per cent soluble after 24 hours' 

 action of the lime, 22.15 per cent after 48 hours, and 22.26 i)er cent after 72 hours. 

 Perphosphate of iron, originally containing 2.75 per cent of pliosphoric acid soluble 

 in citric acid, showed 21.96 per cent soluble after 24 hours, 22.41 per cent after 48 

 hours, and 22.45 per cent after 72 hours. Aluminium phosphate, containing originally 

 3.2 per cent of phosphoric acid soluble in citric acid, showed 18.45 per cent soluble 

 after 24 hours, 19.88 per cent after 48 hours, and 20.65 per cent after 72 hours. "It 

 is essential that the lime should be in the form of hydrate, the carbonate being of no 

 value whatever." 



What is the minimum content of lime in soils which respond to liming? 

 LiLiENTHAL {Deut. Landw. I'resse, 29 {1902), Nos. 22, pjp. 183, 184; 23, i)p. 195, 196; 

 25, ]>p. 210, 211). — Comparative tests of lime, marl, etc., on a number of different 

 kinds of soil are re^jorted. 



What practical deductions can the agriculturist draw from a knowledge of 

 the calcium carbonate content of soils? M. Passon {Deut. Landw. Presse, 29 

 {1902), No. 39, pp. 336, 337). — The author reviews a large number of experiments 

 with fertilizers by different investigators to show that the action of different ferti- 

 lizing materials is very largely dependent upon the lime content, especially assimi- 

 lable lime, of the soil. 



Irish soils, including the peat, G. H. Kinahan {Farmers^ Gaz., 60 {1901), No. 

 51, pp. 922; 61 {1902), Nos. 4, ]>■ 51; 5, p. 69; 7, p. 101; 10, pp. 156, 157; 12, p. 196; 13, 

 p. 212). — A criticism of the publications of the Department of Agriculture and Tech- 

 nical Instruction of Ireland relating to soils, and a plea for the Geological Survey to 

 undertake the study and mapping of soils, with suggestions as to how this should be 

 done. The use of commercial fertilizers and of indigenous fertilizing materials, the 

 soil-forming agencies, and the occurrence and character of the peat bogs are dis- 

 cussed. 



Causes of sterility in peat soils, J. Dumont {Compt. Rend. Acad. Sci. Paris, 133 

 {1901), pp. 1243-1246; ahs. in Jour. Chem. Soc. [Loiidon], 82 {1902), No. 472, II, p. 

 169). — "Whilst the nitrogen present in a sample of peaty soil nitrified extremely 

 slowly, it was found that ammonium sulphate added to the same soil was quickly 

 nitrified, indicating that the soil is favorable to nitrification, but not to the produc- 

 tion of ammonia from organic nitrogen. Further exiieriments showed that the dif- 

 ferent samples of peaty soils examined contained very little potassium, and that the 

 addition of potassium carbonate to one of them gave rise to the production of 



