214 EXPEEIMENT STATION EECOED. 



from houses supplied by wells are clogged aud made impervious by tliis greater 

 amount. 



"Further, the danger to wells from the infiltration of cesspools is more feared, 

 and it is understood as never before that in order to maintain the highest 

 degree of health in a family the drinking water used must be above suspicion 

 and not subject to contaminating influences in the vicinity. 



"Again, communities are being aroused to the intrinsic value of maintaining 

 streams in a pure condition — partly because of the value of fish and ice coming 

 from the streams themselves, and partly on the broad ground that water courses 

 belong to the country as a whole, and must be kept pure for the sake of suc- 

 ceeding generations, not spoiled for them on account of the selfishness of a few 

 at the present time. 



"Thus it is that to-day the problem of sewage disposal, while arousing gen- 

 ei-al interest, is recognized as one which requires more than the common sense 

 of an average person, that the force and principles involved are understood to 

 be not those in common use, aud that, for successful disposal of sewage, special 

 knowledge and judgment are required." 



The book divides sewage purification into two processes, (1) preliminary 

 sedimentation, as for example, by means of the Imhoff or Ems tank, and (2) 

 final disposal by subirrigation, sand filter, contact bed, or sprinkling filter. The 

 sprinkling filter system is considered more complicated, and less suitable for 

 this reason, than the others. 



The merits and faults of broad irrigation as a method of disposing of sewage 

 are quite fully set forth. With suitable soil and slope, and proper care, this 

 method is deemed efficient and productive of increased crops, but it requires 

 watchful care and much labor to prevent offense and danger to health. 



The design, construction, and cost of the sewage systems are presented in 

 text, tables, and sketches. 



SOILS— FERTILIZERS. 



Present problems in soil physics as related to plant activities, B. E. 

 Livingston (Amcr. Nat., J/G {1912), Xo. 5J{5, pp. 29.'t-301). — In this paper, 

 which was presented in the symposium on problems of the soil at the Washing- 

 ton meeting of the American Association for the Advancement of Science, the 

 author considers the soil moisture relations of the underground parts of the 

 plant to plant activities. The following summary is given: 



"The soil water relation is of fundamental importance if we are some time 

 to know about and be able to predict aud control i)lant processes. The moisture 

 of the soil, as well as its other features, is most profitably to be studied as 

 plant environment, the relations which obtain between plant activity and soil 

 phenomena comprising a fundamental and primary requirement for the scien- 

 tific advance of our knowledge. The physical nature of the subterranean en- 

 vironment of terrestrial plants is effective in controlling plant activities, mainly 

 with regard to the possible rate of deli^'ery of water by the soil to unit area of 

 absorbing roots. It is highly desirable to study this power of water delivery 

 with reference not only to the growth of plants, but also to other soil charac- 

 teristics, some of which are already commonly measured. The whole problem 

 of the physics of the subterranean surroundings of rooted plants awaits the 

 development of an instrumentation which will not necessitate the preliminary 

 destruction of some of the most important soil properties before the soil can 

 really be studied." 



The temperature of the soil under different conditions, W. R. Dunlop (Agr. 

 News [Barbados], 11 (1912), No. 261, p. 135). — Observations on temperature of 



