Sewage and Sewage Effluents. 



193 



REDUCTION OF BACTERIA AT COLUMBUS, OHIO. 



(JOHNSON, 1905.) 



Thumm and Pritzkow (1903), at the Berlin Experi- 

 ment Station obtained the results tabulated below. 



BACTERIA IN SEWAGE, CONTACT EFFLUENT, AND SAND 

 EFFLUENT AT BERLIN. 



At the experiment station of La Madeleine, in Lille, 

 Calmette (1907) reports 5,000,000 bacteria per c.c. in 

 the crude sewage, 2,900,000 in the second contact effluent 

 and 800,000 in the effluent from the trickling bed. Of 

 20,000 B. coli per c.c. applied to the niters, the contact 

 system delivered 4000 and the trickling bed 3000 per c.c. 

 The average results of examinations made three times 



