588 EXPERIMENT STATION RECORD. [Vol.41 



to be better than the tight-vault privy or the biological privy in that its con- 

 tents can be more easily and safely disposed of. The biological privy is con- 

 sidered of little use under Maine conditions. 



Bural drainage, T. J. LAFRENifeRE {Bui. Sanit. Quebec, 18 (1918), No. 1, pp. 

 110-183, figs. 7). — This report deals briefly with sewage disposal on farms and 

 in rural communities in the Province of Quebec, and gives drawings and brief 

 specifications for sanitary privies and disposal systems consisting of sedimenta- 

 tion tanks and tile absorption areas. 



The treatment of sewage from single houses and small communities, E. B. 

 Phelps (Pith. Health Rpts. [U. S.], 34 {1919), No. 7. pp. 271-276, pis. 2, figs. 2).— 

 Experiments on tlie disposal of residental and institutional sewage are re- 

 ported. The institutional sewage flow was 100 gal. per capita, and in parts 

 per million contained 7.9 parts ammoniacal nitrogen, 20.4 parts organic nitro- 

 gen, and 981 parts total solids, and had an oxygen demand for 24 hours at 20* 

 C. (68° F.) of 121 parts per million. The residental-sewage flow was 21 gal. 

 per capita, and contained 48 parts ammoniacal nitrogen, 65 parts organic nitro- 

 gen, and 1,360 parts total solids per million, and had an oxygen demand of 268 

 parts per million. 



Experiments with preliminary tank treatment were confined to the biolytic 

 tank and the Imhoff tank. The latter was found particularly well adapted to 

 the existing requirements. An average removal of 91 per cent of the settleable 

 solids was obtained with the residental sewage and 97 per cent with the weaker 

 institutional sewage. 



Experiments with sand filters showed that with moderately course sand 

 having an effective size of 0.35 mm. the area required varied with the dilution 

 of the sewage. About 30 sq. ft. of superficial sand area per capita was required 

 for the residental sewage and 45 sq. ft. for the institutional sewage. Sand 

 layers 24 in. in depth were satisfactory. 



Experiments with trickling filters comprised studies of distribution and filter 

 materials. It was found that the lath filter with tipping distributor possessed 

 advantages over all other types tested. This filter is described in detail and 

 illustrated. 



•' The filter proper ... is built up of layers of ordinary laths, the laths of ad- 

 jacent layers lying at right angles to one another and those of each layer being 

 parallel and spaced with clear openings of 3 in. Closer spacing down to f in. 

 yielded less satisfactory results. The laths of each layer are also so spaced 

 that they come over the center of the open space in the second layer below. A 

 filter depth of 6 ft. yields an effluent of high degree of oxidation, and one of 

 3.5 ft. yields an effluent sufficiently oxidized to satisfy the requirements of most 

 situations. A total filter volume of 8 cu. ft. per capita is required." 



" The performance of this filter is much superior to that of a good trickling 

 filter of stone, and in 6 ft. depths, with sul^sequent sedimentation, is approxi- 

 mately equal to that of a well-operated sand filter 2 ft. in depth." 



Sewage disposal, E. D. Rich and F. G. Legg {Mich. State Bd. Health Engin. 

 Bui. 11 {1917), pp. 24, figs. 14). — This is a nontechnical discussion of the sub- 

 ject of the treatment and removal of liquid wastes, prepared for the guidance 

 of the governing bodies of the smaller communities. 



Sewage disposal, L. P. Kinnicutt, C. E. A. Winslow, and R. W. Pratt {New 

 York: John Wiley & Sons, 1919, 2. ed., pp. XVII+547, figs. I4I).— This is a sec- 

 ond edition and complete revision of this work (E. S. R., 24. p. 616) in which 

 the authors have attempted to introduce new data and recent viewpoints in 

 connection with all the topics treated. 



In particular the chapters on screening, sludge disposal, and chemical pre- 

 cipitation have been entirely reconstructed and much enlarged. A discussion 



