352 TRANSACTIONS LIVERPOOL BIOLOGICAL SOCIETY. 



conclusions may be given in his own words : — " The fluids 

 experimented on are inimical to the growth of the Bacillus 

 typhosus, and if these pathogenic bacteria find their way 

 into a bacteriological system of treatment they meet with 

 conditions hostile to their multiplication. We know that 

 typhoid bacilli must find their way into the sewage from 

 the excreta of persons suffering from typhoid fever, but 

 they cannot be present in large numbers, and in the 

 various samples of crude sewage which we have examined 

 we have not found any. Therefore it may be concluded 

 that, allowing that these bacilli reach biological beds or 

 septic tanks, they are present in such small numbers, and 

 the conditions are so adverse to their existence, that they 

 will not survive the treatment." 



(3) Boyce, MacConkey, Griinbaum and Hill (Report 

 Royal Commission Sewage Disposal 2 (cd. 1178, 1902), 

 p. 87, determined the rate at which the bacilli present in 

 the effluents from various septic processes disappeared 

 when the liquid was filtered through sand or earth. The 

 effluent from a Dibdin bed was passed through four feet 

 of earth, and while flowing on to this filter great numbers 

 of typhoid bacilli were added to it, so that the liquid 

 contained much greater quantities than could possibly 

 have been the case in nature. Twenty-four hours after 

 being added to the filter the typhoid germs could not be 

 detected in the liquid flowing from the former. 



(4) These experiments are, however, rather artificial 

 ones and perhaps greater weight is to be attached to an 

 experiment made by Houston (Report Royal Commission 

 Sewage Disposal, 4, Vol. 3 (cd. 1885), 1904, p. 77) with 

 the object of determining to what extent pathogenic 

 bacteria pass through septic tanks and filters. A Cameron 

 tank and contact beds at Leeds were employed in 

 these experiments. Enormous quantities of Bacillus 



