No. 3, July, 1921] SOIL SCIENCE 325 



3, Entry 854).] Bot. Gaz. 69: 94-95. 1920. — This is regarded as "a very critical and exhaustive 

 piece of work." The "results are valuable in elucidating the effects of sterilizing soils by 

 heat."—//. C. Conies. 



2207. Dacknowski, Alfred P. Peat deposits in the United States and their classifica- 

 tion. Soil Sci. 10: 453— 465. 1920. — A review of literature dealing with the extent and systems 

 of classifying peat deposits. — W. J. Robbins. 



2208. Fraps, G. S. Composition of the soils of Archer, Franklin and Harris counties. 

 Texas Agric. Exp. Sta. Bull. 244. 78 p. 1919.— The area of each soil type occurring in the 3 

 counties is given together with the amount of plant food each contains. Each soil is described 

 and its needs suggested. The results of pot experiments on the various soils are given and 

 methods of maintaining soil fertilitj' discussed. — L. Pace. 



2209. Fraps, G. S. The needs of Texas soils for lime. Texas Agric. Exp. Sta. Bull. 

 243. 18 p. 1919. — A general discussion of the effects of lime in which it is pointed out that 

 lime affects the physical character of the soil, aids in the retention of water, and makes phos- 

 phoric acid more available. Experiments are cited which show that it does not render potash 

 more available. Lime aids in making the nitrogen content of the soil more available, result- 

 ing in more rapid impoverishment of soils. As a rule, lime should not be used on alkali soils 

 as the carbonates formed are more injurious than the alkali. Sources of lime for agricultural 

 uses are discussed and methods of applying are described. — The distribution of acid soils 

 in Texas is given. — L. Pace. 



2210. Hasenbatjmer, J. Einfiuss der Bodenreaktion auf die Diingung und Fruchtbarkeit 

 der Kulturboden. [Influence of the soil reaction on fertilizing and on the productivity of the 

 soil.] Mitteil. Deutsch. Landw. Ges. 36:80. 1921. — The author calls attention to the damage 

 to plants from an acid soil and suggests the following method for determining the relative 

 acidity of soils. Thirty grams of soil are shaken for 1 hour with 100 cc. 7.5 per cent solution 

 of KCl. To 10 cc. of the filtrate 4-5 drops methyl red are added. After violent shaking the 

 color will be lilac if the reaction is very strongly acid, carmine if strongly acid, cinnabar red 

 if acid, orange if weakly acid, and yellow if neutral or alkaline. In the last case 10 cc. of 

 filtrate should be used with 5 drops of Azolieuim. If the solution becomes pure blue without 

 a trace of violet or red the soil is strongly alkaline. — A. J. Pieters. 



2211. Hermann. [Rev. of: Loew, Oskar. Ueber die Bedeutung des Kalkes fiir die 

 Ernahrung der Pfianzen, Tiere und Menschen. (The significance of lime in the nourishment 

 of plants, animals, and man.) Naturwiss. Zeitschr. Forst- u. Landw. 16: 309. 1918.] Forst. 

 Rundschau 20: 27-28. 1919. 



2212. JuRiTz, Chas. F. The agricultural soils of the Union. A summary of existing 

 knowledge. South African Jour. Indust. 4: 76-84. 1921. 



2213. Leach, B. R. A study of the behavior of carbon disulfide when injected into the 

 soil and its value as a control for the root form of the woolly apple aphis. Soil Sci. 10:421^51. 

 PL 1-2, fig. 1-8. 1920. — By using buried pieces of roots infected with woolly aphis it was 

 found that the moisture content of the soil limits the effective diffusion of CS2. It cannot 

 be applied effectively when conditions are favorable for killing the aphis without injuring 

 the roots. — W . J . Robbins. 



2214. Lemmermann, O., und L. Wichers. Uber den periodischen Einfluss der Jahreszeit 

 auf den Verlauf der Nitrifikation. [Seasonal influence on the rate of nitrification.] Centralbl. 

 Bakt. II Abt. 50: 33-43. 1920. — An experiment is described in which parallel analyses for 

 nitrates were made monthly for 12 months of samples of soil from the field, and from a quan- 

 tity of similar soil kept in the laboratory under constant temperature and moisture conditions. 

 The curves for the 2 series of tests practically coincide, exhibiting maxima in April and July. — 

 M. A. Raines. 



