This note covers the application of I.C.I. chemicals in sewage disposal. They are liquid chlorine, bleaching powder, sodium hypochlorite, Chloros, ferric chloride, lime, o-dichlorbenzene, and sulphuric acid. Insert: The value of Chlorine in sewage disposal, reprinted from "The Surveyor and Municipal and Country Engineer" April 13, 1934. "The prevention of ponding on sewage filters by means of chlorine treatment" reprinted from the Journal of the Society of Chemical Industry, April 7, 1933, Vol. LII, No. 14, "Chemical Industry," pp. 297-299. The Chlorination of sewage for prevention of Septicity by J. Haworth. Reprinted from the Journal of the Society of Chemical Industry, September 15, 1933, Vol. LII, No. 37, pp. 293-296. Chemical control of sewage chlorination, the use and value of the O-Tolidine test by C. Lea, reprinted from the Journal of the Society of Chemical Industry, Aug. 11, 1933, Vol. LII., No. 32, pp. 245-250.