SOILS FEKTILIZERS. 215 



"(2) Dissolve the teaspoonfnl of chlorid of lime in a cupful of water, making 

 sure that all lumps are thoroughly broken up, and to it, in any convenient 

 receptacle, add 3 more cupfuls of water. 



"(3) Stir up the mixture, allow to stand for a few seconds in order to 

 let any particles settle (this stock solution if kept in a tightly-stoppered 

 bottle m:iy be used for four or five days), and add 1 teaspoonful of this milky 

 stock solution to 2 gal. of the water to be purified in a pail or other i-eceptacle. 

 Stir thoroughly in order that the weak chloriu solution will come into contact 

 with all of the bacteria, and allow to stand for 10 minutes. This will give 

 approximately one-half part of free chlorln to a million parts of water, and will 

 effectually destroy all typhoid and colon bacilli, or other dysentery-producing 

 bacilli in the water. The water will be without taste or odor, and the trace of 

 free chlorin added rapidly disappears." 



Sewage disposal and treatment {Mo. Bui. Carnegie Libr., Pittsburgh, 15 

 {1910), No. 9, pp. 488-521). — This is a classified list of references to books 

 and periodical literature on this subject apiDearing up to November, 1910. 

 Numerous references to literature bearing on the agricultural use of sewage 

 are given, especially under the head of " broad irrigation." 



The ImhofE clarification tank, D. H. Thomson {Surveyor, //O {1911), No. 

 lOS.'t, pp. 548-551). — Tests of this method of sewage purification are reported 

 with descriptions of the character of the px'oducts obtained, particularly the 

 sludge. It is shown that the holding of the sludge in the tanks until thoroughly 

 decomposed, as is done in this process, greatly reduces the volume and water 

 content of the sludge, but improves its value as manure. 



SOILS— FERTILIZERS. 



Soils, E. Ramann {Bodenkunde. Berlin, 1911, 3. rev. ed., pp. XV+619, pis. 

 2, figs. 63). — In this, the third revised edition of this work, the more important 

 changes in the manner of treatment of the subject matter made necessary by 

 recent advances in the science of soils are as follows: 



(1) The subject of weathering of silicates is treated on the basis of hydraulic 

 processes, and the action of acids, particularly cai'bon dioxid, is given secondary 

 consideration; (2) the clearer understanding of colloids has led. to a recasting 

 of the sections relating to several weathering processes and to numerous other 

 soil reactions and to soil absorption; (3) the decomposition of organic matter 

 in soil is considered on a biological basis; (4) the position is taken that the 

 study of soil physics, especially the relation of the' soil to water, should be 

 made the subject of i-enewed and long continued study; (5) the biology of the 

 soil is given individual consideration for the first time and is treated as a new 

 branch of soil science, giving promise of fruitful results; (6) soils are grouped 

 in climatic provinces but the author has endeavored to give due consideration 

 to former systems of classification. 



The book is divided into six parts as follows: Soil formation, chemistry of 

 soils, physics of soils, biology of soils, physiography of soils, and distribution of 

 soils. A short section is devoted to soil surveying and soil maps. 



Practical soil investigation, E. Heine {Die praktische Bodenuntersucliung. 

 Berlin, 1911, pp. 162, figs. 25, chart 1; abs. in Wasser u. Abicasser, 4 {1911), 

 No. 10, pp. 423, 42-i). — This is the third volume of a so-called library of scien- 

 tific practice published in Berlin, and is stated to be designed particularly for 

 the practical man whose time is too limited for him to consult extensive books 

 of reference on soil investigation. Particular attention is given to the geologic- 

 agronomic relations of the soils of northern Germany, based on the results of 



