WATER SOILS. 761 



In oonchision the author cites numerous authorities for the conchisions that (1) 

 magnesia salts and calcined magnesia in certain amounts at-t injuriously on plants; 

 (2) a moderate liming is ])eneticial to many soils, but excessive liming may reduce 

 the yield; (3) calcium salts reduce the injurious effect of an excess of magnesia, and 

 in j)resence of a suthcient amount of lime the magnesia may play an important role 

 as plant food. The majority of the experiments which have heretofore been made 

 have indicated that for cereals as a rule the best ratio of lime and magnesia is 1 to 1. 

 For other plants, and esj)ecially leafy plants, the amount of lime should be two or 

 three times as great as that of magnesia. 



Examination of soils, R. II. Loucuikidge, E. W. HiLCiARi), et al. {California 

 Sta. llpt. 1'jO,.'-.^, [ip. ..'o-37). — This includes descriptions and analyses of samples of 

 soils from the northeastern lava bed region and the coast range region of California, 

 Si'.cramento Valley, and southern (California, with a discussion of the humus content 

 of the soils of the humid and arid regions of Oregon. The analyses of the Oregon 

 soils show that those of the arid region of that State contain a low percentage of 

 humus, which is rich in nitrogen, while those from the humid region contain a high 

 percentage of hunuis })oor in nitrogen. 



The chemical nature of the soils of Ne-w South Wales, with special refer- 

 ence to irrigation, F. B. Guthrie {Agr. Gaz. New South lla/cs, 14 (190.3), No. 11, 

 pp. 107S-10S7). — Mechanical and chemical analyses of typical soils of the semiarid 

 {)arts of New South Wales are reported and discussed with reference to their adapta- 

 l)ility to irrigation. The average composition of 19 such soils is as follows: Capacity 

 for water, 40 jier cent; volatile matter, 5.7 per cent; nitrogen, 0.08 percent; lime, 

 0.44 per cent; potash, 0.33 per cent; phosphoric acid, 0.21 per cent. These averages 

 are compared with those of a large number of analyses of soils from different ])arts 

 of the world. "From the chemical point of view discussed in this paper there is no 

 room for doubt that the soils of our arid districts are admirably adapted for cultiva- 

 tion by means of irrigation, al)undance of water, properly applied, being the only 

 .tiling necessary to render them extraordinarily fertile." 



Two years' field work of the chemical branch, F. J. Howell [Jour. Ikpt. 

 A(/r. Victoriii, 2 {1903), Nox. 1, p}>. 5-14; '■-, pp. 117-186, pi. 1). — A discussion of the 

 soil rc(juirenients of the different districts of Victoria. 



"Bleisand" and "Orstein," A. Mayer {Landw. Vers. Stat., 58 {1903), No. 3-4, 

 pp. 161-192; abs. in Centhl. Agr. Chem., 32 {1903), No. 12, pp. 798, 795).— These two 

 sul)stances, which are found associated with each other in humus soils, are defined 

 and described. The first is a metallic-gray sand impregnated with humic acid, the 

 second is a slightly coherent chocolate-brown sand strongly impregnated with humates 

 of iron and aluminum mixed with more or less clay. The conditions essential to the 

 formati(jn of the two substances are exj>lained. 



On the influence of the assimilable nitric nitrogen in cultivated soils on 

 the action of tubercle bacteria, F. Nobbe and L. Richter {Landw. Vers. Stat., 59 

 {1903), pp. 167-174; (lbs. in C/iem. Ztg., 28 {1904), No. 3, Reperl. No. 1, p. 6').— Pot 

 experiment during 1895, 1897, and 1898, on the influence of an abundance of nitric 

 nitrogen in the soil on the activity of tubercle bacteria of hairy vetch are reported. 

 The results show that the inoculated soils produced much larger crops, which were 

 richer in nitrogen than the uninoculated soils. The nitrogen assimilation of the 

 inoculated over the uninoculated soil increased as the nitric nitrogen in the soil 

 declined, i. e., it was least the first year (1895) following applications of potassium 

 nitrate (500 and 1,000 mg. of nitrogen to each 4.5 liter pots of soil which already 

 contained 0.4 per cent of nitrogen); greater the second year (1897) when no nitrate, 

 but a large amount of gtirden soil was added, which increased the soil nitrogen to 0.59 

 percent; and still greater the third year (1898) when no fertilizing m^jt^jrial was 

 added and the soil nitrogen was only 0.38 per cent. 



