28 BACTERIOLOGICAL EXAMINATION OF WATER. 



least number of micro-organisms during the months of June, 

 July, and August. 



Frankel and Dietrich examined the water at Marburg both 

 chemically and bacteriologically. The first specimen was taken 

 above the town, the second and third specimens from a place 

 where many drains existed, the fourth one kilometre below the 

 town, and the fifth 7'5 kilometres below the town. The results 

 are shown in the following table : 



Rosenburg studied the Main above and below Wurzburg : 



Above the town, Below the town, 



bacteria per c.c. bacteria per c.c, 



February 520 15,500 



355 2,950 



680 16,000 



780 6,600 



640 6,400 



720 18,000 



565 17,200 



1,020 14.000 



680 22,000 



The River Ure was examined by Frankland ; a specimen taken 

 above Ripon yielded 1800 bacteria per c.c., but a second speci- 

 men taken below the town was found to contain 33,400 bacteria 

 per c.c. In a report to the Corporation of Aberdeen, Frank- 

 land stated that the River Dee above Braemar contained only 

 88 bacteria per c.c., but below Old Mar Castle, having received 

 sewage from Braemar, it contained 2829 bacteria per c.c. 



Lakes. Water from lakes usually contains fewer micro- 

 organisms than river water. Cramer examined fifty specimens 

 of water obtained from Lake Zurich during October and 

 December 1884, and January 1885. During this period the 

 average count was 184 organisms per c.c. From the 13th to 

 the 24th of June 1885, he examined forty-two specimens, and 

 obtained an average result of only 71 organisms per c.c. 



