SEA-FISHERIES LABORATORY. 459 



not done their utmost, with the object of minimising 

 the danger to the public health, to improve the condition 

 of the mussel-bearing areas, and to try and obtain power 

 to deal with this question. I think this activity, and 

 the expense to which this Committee has been put in 

 exercising it, has not been recognised as it ought to have 

 been. It is therefore natural to reply to the public 

 health people with a tu quoque in this matter. At any 

 rate, the remarks on " epidemiological " evidence 

 should be borne in mind in considering the conclusions 

 of the last Section of this Report. 



Standards. 



The same vagueness and " nebulosity " that has been 

 noted in regard to the question of the identification of 

 B. coli may be observed also in the utterances of some 

 public health bacteriologists. Houston (1904, p. 107) 

 thus attempts a classification of bacteriological 

 impurities in estuarine waters with respect to shell-fish 

 contamination. He divides such waters into various 

 classes : — 



(1) No evidence of objectionable contamination — 



no B. coli in 100 c.c. 



(2) Appreciable, though slight evidence— no B. coli 



in 10 c.c, B. coli in 100 c.c. 



(3) Definite signs of pollution. Suspicious — no 



B. coli in 1 c.c, B. coli in 10 c.c 



(4) Obvious signs of pollution. To be condemned — 



no B. coli in 0"1 c.c, B. coli in 1 c.c 

 Here, then, we have a standard. B. coli must not be 

 present in l/10th c.c; if so, the water is objectionably 

 polluted. But, this is only bacteriological condemna- 

 tion, not " necessarily administrative practical or 

 legislative condemnation." 



