SOILS FERTILIZERS. 417 



disease is treated and routine methods of bacteriological work are described in 

 detail. Methods of collecting and labeling samples, registering results, and 

 decimally diluting samples are first treated, and a chapter is devoted to a 

 detailed description of the exact method followed in the examination of a 

 sample of raw river water. Full accounts are included of each day's work, and 

 the composition of the culture media used for the different tests is also given. 



The utilization of sewage in agriculture, J. Grossmann (Rpt. Brit. Axsoc. 

 Adv. ScL. 1913, pp. 771, 772; ahs. in }fcirk Lane Express, 110 {1913), No. Jf277, 

 p. 383; Chem. Ztg., 38 {191J,), No. 34, p. 373).— Abstracts are given of a paper 

 presented at the Birmingham meeting of the British Association, 1913, describ- 

 ing more particularly the system installed by the author at Oldham for the recov- 

 ery of grease and the preparation of fertilizer from sewage sludge (E. S. R., 

 30, p. 19). 



Sewage disposal, G. J. Fowlek {Times [London], 1914, Mar. 11, English 

 Sup.; ahs. in Jour. Soc. Chem. Indus., 33 {1914), No. 7, p. 372).— The extent to 

 which sewage sludge is used as fertilizer in the British Isle.s is discusse<i. 



It is stated that "at Manchester the '.slurry' from the washing of the con- 

 tact beds is being dried, powdered, and sold to Canada at a price which covers 

 cost. At Bradford the crude sewage is ' cracked ' with sulphuric acid, the result- 

 ing sludge hot pressed, the grease recovered and sold nt a profit, and the 

 residual sludge cake sent to northern France for intensive gardening. At Old- 

 ham the sludge is distilled and the residue sold. At Dublin the sludge is fer- 

 mented by yeast, which causes a separation of water; the solid sludge is dried 

 and the resulting powder sold for 50 shillings a ton. An organism has been 

 isolated from the water of an old collierj' which has the property of precipitat- 

 ing iron in presence of organic matter. When this organism was added to an 

 effluent together with a salt of iron and then air blown in, complete clarifica- 

 tion was obtained ; the deposit produced had a high nitrogen content." 



Sewage irrigation and disease organisms, Ciocalteu {Compt. Rend. Soc. 

 Biol. [Paris], 7^ {1913), No. 24, pp. 1411-1413).—A study of the question 

 whether disease organisms applied to the soil in sewage are able to gain entrance 

 into the interior of plants grown on the soil is reported. The results indicate 

 that where there is no injury to the underground parts of the plants the germs 

 do not enter the plant, but that a very slight injury is sufficient to allow the 

 germs to gain entrance. 



SOILS— FERTILIZERS. 



Report of the meeting of the international commission for the mechanical 

 and physical examination of soil, F. Schtjcht {Internat. Mitt. Bodenk., 4 

 {1914), No. 1, pp. 1-31, fig. 1; ahs. in Rev. Sci. [Paris], 52 {1914), I, No. 14, p. 

 439). — This commission of fourteen delegates, representing Germany, Sweden, 

 Brazil, Holland, Hungary, and the United States, discussed methods of me- 

 chanical and physical analysis of soils and agreed upon the following : 



(1) Group soil particles according to Atterberg's classification : Grains greater 

 in size than 20 mm. — pebbles; those from 20 to 2 mm. — gravel; 2 to 0.2 mm. — 

 coarse sand ; 0.2 to 0.02 mm. — fine sand ; 0.02 to 0.002 mm. — dust ; and grains 

 smaller than 0.002 microns — colloidal particles and raw clay. 



(2) Subdivision of groups to be left to the judgment of the analyst. 



(3) Preparation of samples for mechanical analysis by sifting through a 2 

 mm. mesh sieve, soil to be still moist. This applies only to soils rich in humus. 



(4) For sedimentation use apparatus similar to Atterberg's in which all 

 particles up to J mm. in size are separated by sifting, and then levigate samples 

 into a graduated flask. 



