270 Mr. A. W. Blyth. [Nov. M, 



No. of colonies per gram 

 of the sewage 

 taken. 



Sewage containing 5*22 per cent, zinc chlo- 

 ride 6206 



Sewage containing 11*75 per cent, zinc chlo- 

 ride 5764 



Sewage containing 15*67 per cent, zinc chlo- 

 ride 1333 



Mercuric Chloride. — Equal volumes of a 0*1 per cent, solution of 

 mercuric chloride and sewage were mixed together and allowed to act 

 for twenty-four hours. 



To another portion of the sewage mercuric chloride was added so 

 as to be in the exact proportion of O'l per cent. ; this also was allowed 

 to act for twenty- four hours. 



The result was as follows : — 



Ko. of colonies per gram 

 of the sewage 

 taken. 



Sewage containing 0"1 per cent, of mer- 

 curic chloride 550 



Sewage containing 0'5 per cent, of mer- 

 curic chloride 77 



Sewage undisiufected 1,490,000 



Chloride of Lime. — A gram of chloride of lime of average quality 

 was added to 100 grams of sewage and placed in an incubator set at 

 37° ; after twenty-four hours weighed drops of the sewage were 

 cultivated. 



At the same time 2 grams of chloride of lime were added to 

 100 grams of the sewage and digested for twenty-four hours, at the 

 ordinary temperature, and cultivated side by side with the above. In 

 each the sewage had a very distinct odour of chlorine. 



The result of the cultivation was as follows : — 



'No. of colonies per gram 

 of the sewage 

 taken. 



Chloride of lime 1 gram, sewage 100 grams 



at 37° 46 



Chloride of lime 2 grams, sewage 100 grams 



at 17° 1638 



Aniline. — 1 gram of sewage was added to 99 grams of saturated 

 aniline water, allowed to stand at the ordinary temperature of the 

 atmosphere for twenty-four hours, and then drops weighed out and 

 cultivated. 



