94 



MlCr.O-ORGANISMS IN WATER 



various samples tliat Oberbaumbrlicke, Janowitzbrllcke, 

 Friedrichsbrucke, Ebertsbrticke, Marschallbrlicke, 

 Moltkebrucke, Moabiterbrllcke, are all within Berlin 

 and in the main-flow of the Spree. Hafenplatz and 

 Lichtensteinbrlicke are on the middle and lower end of 

 the Landwehr canal, which is largely polluted with 

 sewage ; whilst below Berlin are the Euhlebener 

 Schleuse, situated 1^ mile from the centre of the 

 town ; Spandau, half a mile further down and below the 

 junction of the rivers Spree and Havel ; Pichelsdorf, at 

 the head of the Havel Lake ; Gatow and Cladow, farther 

 on; whilst Sacrow lies at the foot of the lake. As re- 

 gards the bacterial contents of the Spree above Berlin 

 we must refer to Proskauer's experiments, the spot 

 selected being the intake of the waterworks. 



Biver Spree, abstracted at the Intake of the Berlin Waterworks 



(Proskauer) 



Ice. 



These experiments of Proskaner's show that already 

 at the waterworks' intake the Spree contains a large 

 number of micro-organisms, and that in its flow through 

 Berlin these numbers, according to Frank, constantly 



