634 BACTERIA IN WATER. 
Hydrant water, as supplied to cities, has received the attention 
of numerous investigators. The water supply of Berlin was ex- 
amined by Plagge and Proskauer at intervals of a week from June, 
1885, to April, 1886. Their tabulated results show considerable 
variations. We give the figures for a single day, June 30th, 1885: 
Stralauer works, water of the Spree, unfiltered 4,400, filtered 53 ; 
Tegeler works, water of the lake, unfiltered 880, filtered 44; high re- 
servoir at Charlottenberg, 71; 75 W. Wilhelmstrasse, 121 ; Fried- 
richstrasse, 41-42 8. W., 160; Schmidstrasse, 165 E., 51 ; Friedrich- 
strasse, 126 N., 151; Weinmeisterstrasse, 15 C., 63. 
Wells which are supplied by water from deep strata contain few 
bacteria, unless contaminated by surface water in which they are 
usually very abundant. Roth examined the water of sixteen surface 
wells in Belgard, which has a very porous subsoil, and found from 
4,500 to 5,000 bacteria in three, from 7,800 to 15,000 in six, from 
18,000 to 35,000 in six, and 130,000 per cubic centimetre in one. 
Forty-seven wells in Stettin, the water of which was examined by 
Link, gave the following results : Less than 100 in six, 100 to 500 in 
twenty-one, and in the remainder (sixteen) from 1,000 to 18,000. 
Sixty-four wells in Mainz examined by Egger, and 53 in Gotha 
by Becker, gave more favorable results ; the number of wells in the 
former city, in which less than 100 colonies developed from 1 cubic 
centimetre, was 34, and in the latter the same (34). Bolton examined 
the water of 13 wells in Gittingen, and found but 1 in which the 
number of colonies from 1 cubic centimetre was less than 100 ; in 12 
the number varied from 180 to 4,940. 
The water of deep wells and springs may be entirely free from 
bacteria, or nearly so. Egger found in the water of an artesian well 
at Mainz 4 bacteria per cubic centimetre, and the same number was 
found by Hueppe in the deep well at the Wiesbaden slaughter-house. 
The artesian well at the gasworks of Kiel was found by Brennig to 
contain from 6 to 30 bacteria per cubic centimetre. In a spring at 
Batiolettes, Fol and Dunant found 57 bacteria per cubic centimetre. 
Fiirbringer obtained from springs at Jena 156 from one, 51 from 
another, 32 from another, and 109 fromanother. The water supplied 
to Danzig from the Prangenaur Spring was found in several experi- 
ments to be free from bacteria (Freimuth). 
In a summary of results obtained in various German cities Tie- 
mann and Gartner find that ‘sixty-nine per cent of the wells from 
which samples of water were examined contained less than 500 bac- 
teria per cubic centimetre. 
The water of sewers is naturally rich in bacteria. Miquel found 
that at Clichy the sewer water contained 6,000,000 bacteria per cubic 
centimetre. Bischoff found in water from London sewers 7,500,000, 
