86 



MICRO-ORGANISMS IN WATER 



Numerous other investigations of the ice supplied to 

 Berlin are recorded, and in some instances as many as 

 25,000 micro-organisms per c.c. were discovered, whilst, 

 on the contrary, in artificial ice, for the preparation of 

 which distilled water was used, organisms were almost 

 completely absent. 



Still more recently Heyroth l has published a series 

 of investigations on ice as obtained from various places 

 in the neighbourhood of Berlin, and supplied by different 

 companies for public consumption. The following table 

 shows the places from which the ice was collected, as 

 well as the number of bacteria contained in 1 c.c. of the 

 ice-water. 



Bacterial Contents of Ice (Heyroth) 



Day of Investigation Origin of the Ice 



19. 9.85 Plotzen Lake . 

 5.10.85 . 



12.10.85 



Number of bacteria 

 in 1 c.c. 



490 



. 4,900 

 121 



1 ' Ueber den Reinlichkeitszustand des natiirlichen und kiinstlichen 

 Eises,' Arbeitcn a. d. Ttaiserliclien Gesundheitsamte, vol. iv., 1888, p. 1. 



