96 
FILTERED (STORAGE RESERVOIR) VL\TER. 
Percentage of samples showing B. coli and fermentation. 
Date. 
Number 
of 
samples. 
B. coli in— | 
Number 
of 
samples. 
Fermentation in 
lactose broth in— 
Ic. c. ! 
10 c. c. 
1 c. c. 
10 c. c. 
190 V. 
Per cent. 
Per cent. 
Per cent. 
Per cent. 
December 
25 1 
28.0 
76.0 
25 
28.0 
88.0 
190S. 
i 
January i 
26 ! 
15.3 
50.0 
26 
19.2 
80.8 
February 
22 
0.0 
18.2 
22 
0.0 
40.9 
March 
21 i 
0.0 
0.0 
24 
12.5 
41.6 
April 
25 
0.0 
i 4.0 
26 
3.8 
23.1 
May 
21 
0.0 
4.8 
21 
4.8 
i 9. 5 
June 
22 
0.0 
1 4.5 
! 24 
4.2 
20.8 
July ■ 
22 
0.0 
9.1 
24 
0.0 
25.0 
August 
25 
4.0 
8.7 
25 
1 4.0 
16-0 
September 
21 
0.0 
5.2 
; 21 
0.0 
19.0 
October 
26 
1 0.0 
7. 7 
26 
0.0 
11.5 
Noy ember 
24 
0.0 
o 
o 
1 24 
; 0.0 
1 
0.0 
LAFAYETTE SQUARE TAP WATER. 
Percentage of samples giving fermentation in lactose broth. 
Date. 
Number 
of 
samples. 
In 1 c. c. 
In 10 c. c. 
1908. 
June 
6 
Per cent. 
■0 
Per cent. 
33 
July 
14 
21 
50 
August 
25 
8 
40 
September 
18 
0 
38 
October 
4 
0 
25 
WASHINGTON CIRCLE TAP WATER. 
Percentage of samples giving fermentation in lactose broth. 
Date. 
Number 
of 
samples. 
! 1 
In 1 c. c. 
1908. 
June 
Per cent. ' 
July 
5 
23 
20 
4 
0 
13 
20 : 
0 ' 
August . 
September 
October 
In 10 e. c. 
Per cent. 
20 
17 
40 
50 
