416 EXPERIMENT STATION RECOED. 



cal Survey for the purpose of determiuiu^' the discharge of streams throughout 

 the State." 



The bacteriological investigation of drinking water, E. KoHN {Centbl. 

 Bald. [c/f,]. 2. Aht., 23 {1909), No. 1-5, pp. 126-lJ,Jf; abs. in Ghem. Zentbh, 

 1909, I, No. 19, p. i605).— Tests of the iufluence of the character of the culture 

 medium, its chemical reaction, and varying temperatures in the determination 

 of the bacterial content of water are reported. 



Studies on tbe purification of sewage by means of peat beds, A. Muntz 

 and E. Laine {Ann. Inst. Nat. Agron., 2. sen, S {1909), No. 1, pp. 15-59, figs. 3, 

 dgms. 3).— This article describes at length investigations, briefer accounts of 

 which have already been noted (E. S. R., 19, pp. 524, 1014; 21, p. 115). 



SOILS— FERTILIZERS. 



The soil and soil preparation, E. A. Mitscherlich {Fiihling's Landw. Ztg., 

 58 {1909), No. 11, pp. 387-397).— This article, assuming that physically the 

 soil is a mixture of solid particles, water, and air, discusses the influence of 

 physical properties (size of particles, structure, etc.), and the conditions which 

 affect them, for example, depth and time of plowing, upon the productiveness 

 of soils. 



Investigations on the suspension and fiocculation of fine particles in water 

 suspensions, H. Puchner {Landw. Vers. Stat., 10 {1909), No. 3-Jf, pp. 2J,9-261 ; 

 abs. in Chem. Abs., 3 {1909), No. 13, p. J.566).— This article reviews studies of 

 (1) soil particles which are not soluble in water and which are not flocculated 

 by salt solutions; (2) particles which are not entirely insoluble and are there- 

 fore self-flocculating; and (3) particles which are somewhat soluble in water 

 and have thereby lost the power of flocculation even when salt solutions are 

 added. The retai'ding effect of organic substances on the flocculation of sus- 

 pensions is emphasized. Flocculation is promoted by frequent stirring and by 

 a marked decrease in soluble substances. 



Do we possess a practical method of bacteriological soil investigation? 

 H. Fischer {Centbl. Bakt. [etc.], 2. Abt., 23 {1909), Nos. 1-5, pp. 'lU-159; abs. 

 in Chem. Zentbh, 1909, I, No. 19, p. 1605). — As a result of a critical review of 

 the literature of the subject, the author concludes that we do not now possess 

 a method of bacteriological examination of soils which is of practical value. 



The nitrogen cycle and soil organisms, S. F. Ashby {Bnl. Dept. Agr. 

 Jamaica, n. ser., 1 {1909), No. 1, pp. 2-10, i)?s. 2). — An account is given of the 

 processes by which free nitrogen of the air is fixed, nitrogenous matter broken 

 down, and nitrification and denitriflcation brought about. Reference is made 

 to the author's work in isolating a nitrogen-fixing organism from a Jamaican 

 cane soil, as well as from English, Egyptian, East African, and South African 

 soils, the African soils producing " a blue and finally golden yellow diffusible 

 pigment." 



The Jamaican cane soil organism is quite similar to the English type, with 

 similar nitrogen-fixing properties. " It has been impossible, however, up to the 

 present, to find this organism in old pasture and old meadow land showing an 

 acid reaction, but it is always abundant in cultivated soil containing carbonate 

 of lime," A method for isolating and studying the nitrogen-fixing power of 

 this organism which proved satisfactory in the author's investigations is 

 described. 



Previous investigations of the author are referred to as showing " that, under 

 English conditions, nitrification is nearly as active at a depth of 8 in. as at 4 

 in., but only about half as active at a depth of 12 in. from the surface." See 

 also previous notes (E. S. R., IS, pp. 721, 722). 



