iOO THAXSACTIOXS LiVERroOL BIOLOGICAL SOCIETY, 



Bacteriological Analyses. 



(1) Mussels from the beds near the docks (2 analyses). 



(2) Mussels from the beds at Wardley's. 



(3) Estuarine water from the channel near the docks. 



(4) Water from the channel adjacent to the Wardley's 



h'erry Slip. 



(5) Effluents from the fish oil and fish meal works. 



Methods. 



I give an outline of the methods of analj'sis; 

 obviously the comparative value of such analyses 

 depends on the methods employed. Griinbaum's 

 neutral-red, bile-salt, lactose agar medium was employed 

 for the isolation of the bacteria regarded as significant 

 of faecal pollution. 



Five mussels formed a sample. The soft parts were 

 removed from the shells and cut up finely with scissors, 

 then ground up in a mortar, and made up to a volume 

 of 250 c.c. with sterile water. One c.c. of this emulsion, 

 containing l/50th part of a single mussel, was then 

 plated in the agar medium mentioned ; five such plates 

 were made in each analysis. 



One c.c. of tlie water was similarly plated. 



In the case of the manufacturing effluents dilutions 

 were made so that 1 c.c. of each corresponded to 01, 

 001, O'OOl of the original liquid. 1 c.c. of the original 

 Ii(jui(l, and 1 c.c. of each diluent, were plated as in the 

 case of tlie water. In all cases the usual precautioDS to 

 obtain sicrilify of tlie api)aratus and materials used were 

 taken; and control plates to test the vsterility (to the agar 

 medium employed) of the water used for dilution, the 

 air of the laboratory, aiid the hands of the operator, 

 were made. The icsults ol' the analyses were as follows: 



(1) Mussels Fioni 1 he beds near the docks. — 

 (a) Taken at low water of a neaj) tide : The average 



