SEA-FISHERIES LABORATORY. 353 



pyocyaneus (the microbe of green pus) were added to the 

 sewage flowing into the septic tanks. The liquid in these 

 was examined three hours after the inoculation and the 

 microbe was then found. The effluent from the contact 

 beds was then examined, and it was found that Bacillus 

 pyocyaneus was present in it immediately after the first 

 emptying of the beds. Therefore, the Cameron method 

 of treating sewage did not eliminate these particular 

 microbes. It ought, however, to be remembered that they 

 were present in the original sewage to a relatively 

 enormous extent, and that results obtained from their use 

 do not necessarily apply to the typhoid bacillus. 



The conclusion of the Royal Commissioners on 

 Sewage Disposal (Report 4, Vol. I (cd. 1883), 1904, p. xx) 

 on this question may usefully be quoted here. " The 

 treatment of sewage," they say, " according to methods 

 at present in use, cannot be relied upon so to alter its 

 character as to allow of its discharge in the immediate 

 neighbourhood of shellfish layings without incurring 

 considerable risks of disease being communicated by the 

 consumption of shellfish taken from such layings. In 

 such cases the sewer outfall must be removed or the layings 

 closed. In other cases where {e.g.) the layings are at a 

 considerable distance from the outfall, and the sewage 

 would be largely diluted before reaching them, treatment 

 of the sewage might be of value in diminishing risk." 



In the case of the Morecambe mussel beds we have 

 seen that this latter condition is satisfied in so far as the 

 main sewer outfall is concerned. Given good administra- 

 tion, and supposing that the taking of shellfish from the 

 immediate neighbourhood of the outfall is not practised, 

 then it appears that this enormous dilution of the effluent 

 does take place. Danger (if such exists) is to be appre- 

 hended from the continued existence of the discharge of 



Y 



