208 



" Twelve acres of first contact bacteria beds have been cons- 

 tructed at Leicester for this purpose. 



" After bacterial clarification, a much greater volume can be 

 efficiently purified per acre of land, and even where complete 

 bacterial purification is adopted, and where the levels of bacteria 

 beds and adjoining land are favourable, the effluent could in some 

 cases with great advantage and some profit be used for irrigating 

 ordinary agricultural land, especially in dry seasons, the organic 

 matter of the sewage having been largely converted into inorganic 

 substances in the best form and condition for the nutriment of 

 crops without fouling them. 



" Other advantages of preliminary clarification are the avoidance 

 of large areas of uncropped land for receiving crude sewage; the 

 saving in cultivation expenses; increased income from cropped 

 land; and the avoidance of slimy sludge accumulating on the surface 

 of grass or vegetable crops. 



" The extra income derived from the greater produce of sewage- 

 irrigated land is not commensurate with the working expenses, the 

 rent of land and the capital outlay on the sewage disposal works ; 

 but it provides a very considerable asset, and in some cases the 

 working expenses are more than covered; consequently, land uti- 

 lisation of clarified sewage under favourable conditions minimises 

 the cost to communities of the necessary provision of sewage dis- 

 posal works." 



A. H. VALENTINE. The Distillation of Sewage Sludge. Jour- 

 nal of the Society of Chemical Industry., March 15, 1910, 

 p. 244. 



The author describes certain laboratory experiments which he 

 had made with the sludge from the Sewage Works at Oldham., 

 with the object ot determining: a) the character of the products of 

 distillation ; b) the character of the residuum ; and c) the conditions 

 for obtaining the most economical results. 



The sludge was acidified, roughly dried by evaporation, and 

 broken into pieces of about one inch diameter. These were placed 

 in a flat-bottomed cylindrical steam-jacketed copper vessel with a 

 perforated false bottom; the vessel was capable of holding about 

 12 lb., the depth of material in the vessel being about one foot. 

 Attached to the coverhead of the vessel was a long referee's gas 

 tube dipping at the bent end into a large vessel of hot water. Su- 



