SOILS FERTILIZEES. 7 17 



The agricultural use of sewage water, A. Muntz and E. Lain:^ {Vie Agr. et 

 Rurale, 1912, No. 10, pp. 2-'il, 2.J2). — This is a summary account of investigations 

 more fully reported in the article abstracted above. 



Sewage sludge (New York and London, 1912, pp. XI +272, figs. 42). — This 

 book contains translations of articles on Treatment and Utilization of Sludge, 

 by A. Eisner (E. S. R., 25, p. 213) ; The Drying of Sludge, by F. Spillner (E. S. 

 R., 26, p. 118) ; and Operation of Mechanical Sewage Plants, by Spillner and 

 Blunk; as well as an article on Sludge Treatment in the United States, by 

 K. Allen. 



The last article summarizes what has been done by various cities and towns 

 in the United States in the treatment and utilization of sludge. It is shown that 

 up to the present time this subject has received little attention in America as 

 compared with Germany or England, but it is believed that it is becoming in- 

 creasingly important and will therefore command more attention. It is pointed 

 out that European methods can not be applied in this country without modifica- 

 tion on account of the highly dilute character of the average sewage in America. 

 Numerous analyses are given of typical domestic and manufacturing city sewage, 

 as well as of sludge obtained from various city sewage works. The method 

 employed by the city of Baltimore in disposing of night soil on farms near the 

 city is described, and the general subject of land application of sludge is briefly 

 discussed. The general conclusion on this point is that the economical use of 

 sludge as a fertilizer is exceptional and therefore the laud disposal of this 

 material is reduced to either drying or burying. 



SOILS— FERTILIZERS. 



The theory and practice of soil management, F. K. Cameron (Rpt. Mich. 

 Acad. Sci., 13 {1911), pp. 55-63). — The author discusses the different soil factors 

 of crop production, stating that the practice of soil management " is rapidly 

 becoming a highly developed art which needs for its best application a compre- 

 hensive coordination of the labors of the physicist, chemist, biologist, and other 

 Investigators, and a clearer understanding between the layman and the expert 

 as to how they may be mutually helpful." See also a previous note (E. S. R., 

 26, p. 422). 



Soil and soil problems from the standpoint of the physicist, J. A. Jeffery 

 {Rpt. Mich. Acad. Sci., IS {1911). pp. 36^39, fig. i).— As one of the factors of 

 crop production on Michigan soils, attention is being given to the study of soil 

 temperature. Some of the questions to be determined are the normal tempera- 

 ture of the different soil types, the variations of any individual of a type below 

 normal, the practicability of raising the temperature toward or above normal 

 by proper practice, and the effect of such rise in soil temperature on crop 

 production. 



Experiments at the Michigan Station " show that an application of 10 tons 

 of manure per acre, worked to a depth of 6 in. into the soil when apparently 

 no other influences are at work, results in a temperature rise of about 0.15° F. 

 In sunshiny weather the temperature of the soil receiving this 10 tons of manure 

 per acre is raised over 2°, apparently because of the increased capacity of the 

 soil to absorb the sun's heat." 



Soil and soil problems from the standpoint of the chemist, A. J. Patten 

 {Rpt. Mich. Acad. Sci., 13 {1911). pp. J/O-'fS). — In this discussion the author 

 emphasizes the fact that investigations on the chemistry of the soil must take 

 account not only of the inorganic plant food constituents but of the organic 

 compounds as well. In his opinion none of the methods proposed for determin- 

 ing the availability of the inorganic plant food has a sound, scientific basis, but 



