Al 
the river along the banks. The main point which is demon- 
strated by practically all these samples is that in rainy weather, 
when the river is muddy and contamination gross, the class 
glucose ~ lactose + is extremely common, and 4 months later, 
in February, when the river is clear, the reverse is the case. 
Particular attention is drawn to the comparison between the 
3 filtered waters of Pulta, Tallah and Wellington Square in 
the months of November and December. Note the great pre- 
valence of the class glucose + lactose + in Wellington Square, 
as compared with the Pulta and Tallah samples. The explan- 
ation of this fact is that highly polluted subsoil water was 
making its way into the Wellington Square reservoir during 
this period. This was proved by other bacteriological evidence, 
and by inspection of the reservoir. As the level of the subsoil 
water sank, the pollution ceased, so the relation between these 
two classes of organisms (glucose + lactose +, and glucose + lac- 
tose—) assumes what may be called the normal during the 
months of January and February. 
TABLE VI(c). 
After Houston. 
Number of typical B. coli per 100 coli-like mucrobes of all sorts. 





| . 
THAMES. LEE. | Xe NEW RIVER 
1908-9. a 
(ae SE ae ites ee ee a 
Month. | Raw. | Filtered.| Raw. | Filtered, en Raw. | Filtered. 
| 0/ O/ O/ | iY) oO 
| /O Oo } /O O Oo 
Averages, 1907-8 | 80'5 54°9 84°2 45°7 ay 79°4 54°6 
April, 1908 : | 81°8 Ages S7°2 25°O 72°9 26°3 
| (1 out of 4) ol 
May Sater Saat 30°6 79°7 20°0 Saga! 25°97 
| atte 
June md | Gene 30°7 73°6; | 51°60 OO Le hy 2374 
July ‘ 69°38 |! 37°9 88°5 | 29'0 TO" eh) B56 
| | 
August ee |) | Berar | eats 79°5 14°3 7e°5 y, ' 30% 
September ue 71°4 26°2 83°1 | 30°0 74°6 60°0 

