194 TRANSACTIONS LIVERPOOL BIOLOGICAL SOCIETY. 



substance, and the smell disappeared completely after 

 two days. They were very slightly turbid, but no more 

 so than ordinary river water. 



In February, 1908, a sample of one of these 

 effluents was sent to me for examination. It was highly 

 septic, containing (in nutrient agar cultures), over 

 100,000 and less than 1,000,000 bacteria per c.c. It 

 contained no antiseptic substances, and when dosed with 

 sugar an abundant growth of bacteria and infusoria 

 appeared. It had the same offensive smell possessed by 

 the effluents examined this year. It was subjected to 

 chemical analysis at the County Laboratories, and gave 

 the following results : — 



In parts per 100,000. 



Total solid matter in solution... ... 1633'2 



Oxygen required to oxidise in 



(1) 15 minutes ... ... ... 3*7 



(2) 4 hours 11-8 



Ammonia ... ... ... ... 12'5 



Ammonia (from organic matter by dis- 

 tillation with alkaline permanganate) 5'4 



Sulphuretted hydrogen ... ... 036 



Mixed with tap water (10 per cent, effluent and 

 90 per cent, water) and allowed to stand three hours, the 

 mixture lost five-sixths of its total dissolved oxygen; 

 and allowed to stand twenty hours it lost twelve- 

 thirteenths of its dissolved oxygen. The Analyst 

 reported that " Fish would be suffocated for want of air 

 in such a mixture of effluent and water, or even with a 

 smaller proportion of effluent." 



I did not collect this sample myself, and am 

 therefore unable to say whether or not the effluent may 

 have been accidentally contaminated by bacteria 

 during collection. 



