BY THE HON. W. F. TAYLOR, M.L.C. 29 



The process has been in operation at Acton for the last three 

 or four years, and appears to be a very simple one, and requiring 

 only a small area of land. Three tanks are used, the ferozone 

 being mixed with the sewage before the latter is admitted into 

 them ; and after precipitation of tlie suspended matters, the 

 effluent is made to pass through the small filters composed of 

 polarite and stind. The filter has four inches of coarse gravel 

 at the bottom through which run 4 -inch pipes. Upon this pea 

 gravel is laid to the depth of four inches, then six inches of sand, 

 five inches of polarite mixed with five inches of sand, and, 

 finally, nine inches of sand. The effluent passes downwards on 

 the intermittent principle. Dr. Arthur iVngell, Ph.D., F.I.C., 

 says, respecting it : — •' The ferruginous effluent from the tanks 

 is poured through a filter composed of polarite mixed with sand, 

 which will filter sewage effluents at the rate of 1000 gallons per 

 square yard per twenty-four hours with better results than can 

 be obtained by land, wIulIi filters about 1^ gallons per square 

 yard per twenty-four hours ; or, in other words, one acre of 

 filtering area containing a layer of polarites will do more efficient 

 work than G6G acres of land." The value of this discovery can 

 scarcely be overestimated, as by the use of these small but 

 powerfully-active filter-beds it is entirely unnecessary to acquire 

 large areas of bind for sewage farms : the polarite in these beds 

 never requires to be changed, or to be removed — -a slight rest of 

 a few hours occasionally being all that is needed to effect re- 

 vivification, and to admit of the top of tlie filter Ijeing cleansed. 



" The action of the polarite is entirely independent of any 

 property inherent to the polarite itself, which remains the same 

 in weight and hulk after an indefinite amount of oxidising work 

 has been done. Polarite is simply a carrier of oxygen and a 

 means of bringing about a contact between that element and the 

 foul matter in the filtering bed. It derives its oxygen from the 

 air and also from the tank fluid, and as these sources are in- 

 exhaustible, so also is the life and power of the filter-bed." 



Sir H. Roscoe says : — ■" As the sewage at Acton is received in 

 the fresh state, the li(|uiil has not yet lost ils dissolved oxygen, 

 nor has the greater part of the organic matter been broken up 

 infco soluble and therefore non-hurtful product^. The larger 



