736 



A MANUAL OF BACTERIOLOGY 



Examination of Sewage and Effluents. 



EFFLUENTS ONLY. 



8. Incubate some of the effluent in beakers at 22 C. and 37 C. for some 



days. A good effluent should yield little or no unpleasant odour (an 

 unpleasant odour indicates the presence of decomposable organic 

 matter, and such an effluent might give rise to a nuisance). 



9. Place a gold-fish or two in a bowl of the effluent. The fish \vill live in, 



and be unaffected by, a satisfactory effluent. (This may be done 

 only by a licensee under the Vivisection Act.) 



in the udder, 1 as delivered to the consumer may contain 

 an appalling number of bacteria. In milk as ordinarily 

 supplied there are from one to five million bacteria per 

 cubic centimetre, and it frequently contains ten to fifteen 



1 The " fore " milk may contain organisms which have lodged in the 

 milk-ducts, and it is extremely difficult to obtain completely sterile milk. 





