29 
In the following tables are given the results of the bacteriologic 
examinations of samples of the raw river water and of the filtered 
water : 
THE RAW RIVER WATER. 
Table showing the number of bacteria and presence of colon bacilli found in samples taken 
from the inlet of Dalecarlia Reservoir. 
[Daily examinations made by the (a) Laboratory of the Filtration Plant; (6) Bureau of Plant Indus- 
try of Agricultural Department; (c) Hygienic Laboratory, Public Health and Marine-Hospital 
Service.] 
MAY. 
Date. 
1907. 
May 15 . 
16. 
17- 
18. 
19. 
20. 
21 . 
22 . 
23. 
24. 
25. 
26. 
27- 
28. 
29. 
Number of bacteria 
per cubic centime- 
B. coU in- 
(a) 
Filtra- 
tion 
plant. 
(&) 
Agri- 
cultural 
Depart- 
ment. 
(c) 
Hygi- 
enic 
Labor- 
atory. 
0.1 c. c. 
900 410 1, 700 
800 I 240 1,800 
460 I 515 1,080 
210 I no '520 
i- 
1 c. c. 
+ (c)(a).... 
+ (c) 
+ (c) 
+ (a)(6)(c) 
10 c. c. 
Fermentation in sugar 
broth (c). 
0.1 c. c. 
+ (a)(6)(c) 
+ (a)(6)(c) 
+ (a)(6)(c) 
+ (a)(6)(c) 
1 c. c. 
10 c. c. 
850 
1,300 
850 
300 
280 
550 
122 
372 
188 
240 
340 
175 
1,000 
1,720 
1,850 
460 
580 
280 
-t-(a) (c). 
P(a) (c)... 
+ (c)- 
+ (a) (c)... 
+ (a) 
-f(a) (6)... 
+ (a) (c) . . 
+ (a) (6)(c) 
+ (a)(6) (c) 
+ (a)(6)(c) 
-I- (a) (6)(c) 
-(a)(6)(c) 
550' 
700 
750 
268 
184 
84 
290 
470 
580 
+ (c) 
+ (a) (c)... 
+ (a) (c)... 
+ (6) (c) - 
+ (a) (6) . 
P (a) (c) . 
- ! 
650 
Average 
653+ 
195 
+ (a) (c). 
+ (a)(6)(c) 
245 + 
913+ 
