ACTION OF DIBDIN CONTACT BEDS 69 
January 23rd. — An analysis of the sand of the bed was made. 
January 23rd, 1900 
per gram. 
B. coli 
B. enteritidis 
sporogenes 
Top ot" Bed 
34,000,000 
33.000 
Present in 0.0 1 gram. 
Middle 
2,000,000 
300 
Absent in 0.0 1 gram. 
Bottom 
*46,ooo,ooo 
700 
Absent in 0.01 gram. 
January 24th, 1900. — The surface of the filter was skimmed off. An 
analysis of the first filtration gave the following results : — 
January 24th, 1900 
Bacteria per c.c. 
B. coli 
B. enteritidis 
sporogenes 
First 10 minutes ... 
75,IOO 
6, IOO 
Absent in 0.8 c.c. 
(clot) 
After 1 hour 
63,500 
5,900 
Absent in 0.9 c.c. 
(clot) 
January 31st, 1900. — Samples of the effluent were taken after the bed had 
been working for a week. 
January 3 1 st, 1 900 
Bacteria per c.c. 
B. coli 
B. enteritidis 
sporogenes in 1 c.c. 
Average of Samples taken 
every \ hour for 3 hours. . . 
40,800 
6,733 
Present 
Last of effluent coming 
from bed 
30,300 
4,800 
Present 
Bacteriological Investigations of the Storm Water Filter Beds 
On January 22nd, 1900, during a period of heavy rainfall, bacteriological 
analyses were made of the effluents of the Storm Water Filter Beds. 
Source 
Bacteria per c.c. 
B. coli per c.c. 
B. enteritidis sporogenes 
Crude Sewage and Storm Water, 
W. outfall 
5,360,000 
31,400 
Present in 1 c.c. 
Crude Sewage and Storm Water, 
E. outfall 
946,700 
9,300 
Effluent from Burnt Ballast 
Filter 
1 49,600 
4,!33 
Absent in .01 c.c. 
Effluent from Cinder Bed Filter 
290,600 
733 
Absent in .01 c.c. 
One organism chiefly. 
