714 EXPERIMENT STATION RECOED. 



disruption by meclianical measures the processes of agglutination and subse- 

 quent sedimentation account for tbe negative bacterial content of water stored 

 in glass vessels at laboratory temperature. 



The importance of the quantitative determination of chlorids in the 

 examination and judgment of drinking water, F. Malmejac {Compt. Rend. 

 Acad. Sci. [Paris'\, 158 {1914), No. 9, pp. 650-652; abs. in Rev. Sci. lPans'\, 

 52 (1914), I^ No. 11, p. 348). — The author maintains that any notable increase 

 in the chlorin content of a drinking water is an indication of contamination. 

 The determination of chlorin, therefore, furnishes a simple means of detecting 

 possible contamination. The indication of contamination afforded by a marked 

 Increase of chlorin should, however, be confirmed by complete analysis. 



The taste of hard water, A. Feiedmann {Ztschr. Hyg. u. Infektionskrank., 

 77 {1914), No. 1, pp. 125-142). — Experiments are reported which show that the 

 presence of carbon dioxid, even in very small amounts, imparts a distinct taste 

 to water and that this furnishes a means of rough classification of waters with 

 reference to hardness. 



A list of references to articles bearing on this subject is given. 



The influence of waste iiquors from potassium chlorid factories on the 

 biological purification of water supplies, A. Muller and L. R. Fresenius 

 {Arb. K. Gsndhtsamt., 45 {1913), No. 4, PP- 491-521, fig. l).—lt was found that 

 3,000 parts of chlorin per million of the raw water did not injure the biological 

 properties of the water for domestic and industrial purposes, but that 6,000 

 parts per million and over caused a marked injury. Oversalting with waste 

 liquors retarded and, in some cases, prevented putrefaction. The increased 

 specific gravity of the oversalted water hindered sedimentation. 



SOILS— FERTinZERS. 



Humus in California soils, R. H. Loughridge {California 8ta. Bui. 242 

 {1914), pp. 49-92). — This bulletin discusses the nature and value of humus as 

 a soil constituent and presents in detail results of a systematic study of the 

 distribution and composition of humus in each agricultural district of Cali- 

 fornia. 



It was found that humus was distributed in California soils to a depth of 12 

 ft. or more. On account of this wide distribution the percentage is smaller 

 although the total amount is larger than in soils of humid regions. In the 

 first 3 ft., which is considered the soil proper, the California soils contain more 

 humus than soils of humid regions, and the amount in the soils to a depth of 

 12 ft. is more than double that found in humid soils. The surface soils of 

 California contain on an average 1.28 per cent of humus. The upper 3 ft. of 

 soil proper show an average of 1.06 per cent of humus per foot. The tule 

 swamps have the highest percentage of humus; the deserts the least. The 

 amount of humus is less in close, compact adobe clays than in lighter loam and 

 sandy soils. The soils of the Coast Range valleys in the western part of the 

 State have a higher percentage of humus than those of any other agricultural 

 region of the State, probably because of the greater humidity and denser vege- 

 tation of that region. 



Attention is called to the fact that the black color of the soil is not always 

 due to a high humus content, since many black soils examined showed a smaller 

 percentage of humus than soils of a gray color, and some contained no humus 

 at all. The humus content was sometimes less in the first foot than in the 

 second as a result of the destruction of organic matter by cultivation and 

 summer fallowing. 



