620 EXPERIMENT STATION RECORD. 



is reiKlered difficult by the water-carriage system of sewage disposal in geueral 

 use. 



The use of large quantities of dilute sewage on laud tends to make the soil 

 cold and to retard nitritication. A further difficulty is the tendency of the 

 fatty and soapy matters in the sewage to clog the soil. These difficulties have 

 led to the adoption of processes of removing the suspended and precipitable 

 matter in the form of sludge. The author is of the opinion that the fertilizing 

 value of this sludge has been exaggerated, and that " the manurial value of 

 sewage as it is now generally met with, and whether it be in the form of crude 

 sewage, of sewage deprived of its solid matters, or of sewage sludge, is but 

 very small." The nitrogen in sewage sludge is considered as " not nearly so 

 available as in artificial manures, and richness in nitrogen is not a test of 

 the comparative value of sludges." 



On the whole, the author is of the opinion that the agricultural results with 

 sewage are of secondary importance as compared with the need for speedy 

 and effective sewage disposal. 



SOILS— FERTILIZERS. 



Investigations on the relation of the physical properties of soils to one 

 another and to mechanical analysis, A. Frankau {Untcrsiiclnnujen iibcr 

 (lie Bczichungrn dcr pliysikaliscJini Bo(Jeneigciis;cJi(iftcn zueinandrr mxl ziir 

 meclianischcn BodenanaJyse. Diss. K. Tech. Hochschule Miinchcn, 190D, pi). 

 Ji6; rev. in Zentbl. Agr. Cttem., 39 {1910), No. 6, pp. 359, 360).— This is a review 

 of a dissertation dealing with investigations on water capacity, permeability, 

 cohesion, hygroscopicity. heat generated on moistening, and other phj-sical 

 properties, as well as mechanical soil analysis, in their interrelations on quartz 

 sand, calcareous sand, humus sand, loam sand, marl, loam, and clay.. The 

 author concludes that, in general, there was a definite relation between the 

 physical properties of the sands and sandy soils, the loam and the clay, and the 

 mechanical analysis as made by the Kiihn and Schone methods. Tliere was, 

 however, no such relation in the case of the humus sand and the marls because 

 both humus and lime have a specific influence uiK)n the physical properties of 

 soils. The reviewer questions whether the conclusions drawn by the author are 

 borne out by the data which he reports. 



On shrinkage of mud i" gyttja ") and peat on drying, E. Haglund 

 (Svcnska Mosskiiltiirfor. Tidski:. 21, {1910), No. 1, pp. i-6').— A method for 

 determining the percentage shrinkage on air-drying of soils rich in organic 

 matter is described, and the results obtained with 22 different soil samples are 

 given. 



The nature and importance of soil maps, C. Eberhart (Naturw. Ztschr. 

 Potest u. Landw., 8 { 1910), No. 4-5, pp. 193-211). — This article discusses the kind 

 of data which should be included in soil maps and their preparation and use. 



Soils of Nova Scotia, M. Cumming {Ann. Rpt. Sec. Agr. Nova Scotia, 1909, 

 pt. 2, pp. 3-10, map 1). — It is stated that no thorough survey of the soils of 

 Nova Scotia has been made, but that arrangements had been completed for such 

 a survey to begin in the summer of 1910. This article deals with general obser- 

 vations, describing the geological formations from which the soils are derived 

 and the principal classes of soils which occur. 



Agrologic study of the soils of Brittany, L. Fourton and F. Gandon {Etude 

 Agrologique des Sols de Bretagne. Rennes, 1909, pp. 23; rev. in Bui. Soc. Nat. 

 Agr. France, 70 {1910). No. 11, pp. 16 J,- 1 67). —The soils of Brittany are of very 

 diverse origin, but as a rule are poor in lime and phosi)horic acid. The 68 

 analyses reported show that while certain of the soils derivetl from gneiss, 



