120 TRANSACTIONS LIVERPOOL BIOLOGICAL SOCIETY. 



have not general application. Other conditions, varying in 

 every channel and estuary, must be considered. The nature 

 of the foreshore, and the facilities for transport to and from 

 the cleansing grounds are important factors, and they determine 

 whether or not this method of cleansing is practicable. 



About the same time the Conway Corporation made 

 proposals for cleansing the mussels taken from the grounds 

 under their control by treatment with sterilised sea- water. 

 There were many practical objections to the proposal for 

 relaying the mussels on the part of the foreshore where I had 

 made my experiments, and at no other place could unpolluted 

 sea-water be obtained. The Corporation suggested, therefore, 

 to pump sea-water into large tanks, and then to sterilise this 

 water by adding chlorine solution. After removal of the 

 chlorine the sterile water was to be made to flow over the 

 mussels in the cleansing tanks. The Chairman also requested 

 me to test this process on a small scale so as to obtain some 

 indications of the minimal proportion of chlorine necessary 

 to destroy the sewage bacteria, and the maximal proportion 

 which the mussels could stand without injury to their normal 

 functioning. The length of time required for cleansing, and 

 some other points, were also to be investigated. Accordingly 

 Mr. A. Scott and I made some experiments at Piel during last 

 April and May, and I repeated these experiments, with some 

 others, at Liverpool later in the year. 



Only a few direct experiments were, however, made. It was 

 soon seen that it was theoretically possible to cleanse mussels 

 by means of sea- water rendered practically sterile by dosage 

 with chlorine. This knowledge, however, goes only a little 

 way, and it does not seem possible to anticipate, merely by 

 laboratory experiments, the difficulties that are sure to be 

 encountered in working the process on the commercial scale. 

 Some time afterwards, the Conway Corporation obtained a 

 grant from the Development Commissioners to make this 



