THIS report contains an account of the experiments carried out by the London County Council during the years 1902 and 1903. The main conclusions arrived at by Prof. Clowes in the first part (chemical and general) of the report are that coke is a suitable material for bacterial beds and does not disintegrate during use, that the bacterial effluent of settled sewage from such beds does not undergo offensive putrefaction and supports fish life, and that the use of chemicals is unnecessary when this mode of treatment is adopted. In the second part Dr. Houston deals with the bacteriological portion of the experimental work. His results seem to show that though the number of bacteria in the effluent from coke beds is less than in the corresponding crude sewage the reduction is not well marked, and while the bacterial effluent is chemically satisfactory, the bacteriological results are usually quite the reverse, because the microbes pass through the coke-beds. There seems to be small ground for belief that the typhoid bacillus would be destroyed in the beds; an important conclusion. The Experimental Bacterial Treatment of London Sewage. (London County Council.) By Prof. Frank Clowes, and A. C. Houston. Pp. xii + 242. (London: P. S. King and Co.) Price 10s.