WATER — SOILS. 385 



The effect of acidity on the development of nitrifying organ- 

 isms, E. K. EwELL and H. W, Wiley {Jour. Amcr. Chem. Hoc, 18 

 (7.s'.V6), So. 6, pp. 475-484). — A brief history of investigation on the 

 transformation of nitrogen in the soil and on the influence of the reac- 

 tion of media on the growth of organisms is given. One hundred cubic 

 centimeter portions of a solution, composed of ammonium sulphate 

 0.943 gm,, di-potassium hydrogen i)hosphate 1 gm., magnesium sulphate 

 0.5 gm,, calcium chlorid trace, and water 1,000 cc, were inoculated with 

 portions of 40 samples of soils from different parts of the United States, 

 and the amount of nitrogen nitrified during 2 mouths determined. 

 Before the addition of the ammonium salt the acidity of the culture 

 medium was such that 1 liter of it required 2.0 ec. of normal sodium 

 hydroxid solution to make it neutral to phenol phthalein. On an average 

 28 i^arts per million of nitrogen were nitrified during the 2 months, 

 but nitrification stopped "after the formation of an acidity equal to 3 

 to 4 cc. normal alkali. . . . The organisms coming from various parts 

 of the country seem to be very uniform in regard to their ability to 

 endure acidity." 



Similar results were obtained when the tests were repeated with pure 

 cultures of organisms isolated from the different soils. It was shown 

 that the nitric ferment was able to endure at least as much acidity as 

 the nitrous ferment. 



The presence of nitrites in the air, G. Defren ( Tech . Quart., (1S9G), No. 3 and S, 

 pp. 338-245). — It was found that water exposed, to the air of well-ventilated rooms 

 absorbed small quantities of nitrites, the amount increasing with time of exposure, 

 and depending upon the character of the work going on in the room. The burning 

 of illuminating gas results in the formation of some nitrites. The lowest amount 

 observed was 0.014 part per 10,000 of water, the highest 0.0707 part. If the air 

 was drawn through the water no reaction for nitrites was obtained, the same being 

 true when the breath was blown through distilled water. It is suggested that the 

 deleterious effect of air of overcrowded rooms may in part at least be accounted for 

 by the presence of nitrites which possess poisonous properties. 



Artesian >wells as a means of -water supply, W. G. Cox {Brishane: Capsford Jl' 

 Co.; Xew York: Van Nostrand Co.). 



Typhoid fever in Indiana and its possible connection Twith •water supplies, 

 S. BuRRAGE {Purdue UnirersUy Monographs, Puhllc Health Series, No. S and 4, pp. 

 3l-2'>). — The nature and dissemination of typhoid fever is discussed and precautions 

 to be observed to prevent contamination of water supply are explained. 



On the purification of -water supplies of cities and to-wns, S. Bukrage {Vnr- 

 dite I'niversilii Monograjjhs, Piihlic Health Series, No. 3 and 4, pp. 1-30, jigs. 4, p\. 1). — 

 This ia a i)opular discussion of the impurities commonly found in drinking waters, 

 and some of the latest methods for purilication of w.ater. 



A study of the vrater of different springs in the park in Grignon, .). Cruciie- 

 TKLi.E (Ann. Agron., 33 (ISOG), No. 10, pp. 4i:0-4S4, Jigs. ;?).— The aumuut of nitric 

 nitrogen carried off in the natural drainage is estimated. 



A study of the ^waters along the railw^ay from Sfax to Loued Seldja, E. Ber- 

 TAiNCHAUi) (Jiiil. Agr. et Commerce, 1 (1896), No. 1, pp. 30-41). 



Water analysis, .T. B. Lind.sey et al. (Massachusetts Hatch Sta. Rpt. 1805, pp. 

 233-325). — The method followed in water analysis is described, and instructions for 

 sending samples are given. Analyses have been made of 124 samples. Sample 

 analyses of difiterent waters are given. 



The absorptive povsrer of humus soil, M. Lacuaitd (Bui. Soc. Chim. Paris, ser. 3, 



