BACTERIOLOGICAL INVESTIGATIONS 117 
Monthly Analyses Average number of 
bacteria per c.c. 
Vyrnwy Water. — Samples taken at Prescot ... ,.. ... ... ... 38 
Rivington JVater. — Samples taken at Prescot ... ... ... ... ... 34 
Dudlow Lane JVeh ... ... ... ... ... ... ... ... 48 
Green Lane JVcll (excluding temporary increase througli disturbance by 
workmen) ... ... ... ... ... ... 95 
Whuhor IV ell ••• ... 57 
SPECIAL INVESTIGATIONS 
Rivington 
The unfiltered water going on 'the filtered water-beds contained 100 bacteria per c.c. 
The average in the filtered water was 30 per c.c. 
Lake Vyrnwy and Oswestry 
Samples taken from various parts of the lake and from various depths gave an average 
number of 31 bacteria per c.c. Samples from the principal feeders of the lake gave an average 
of 91 bacteria per c.c. An examination of the water at several points along the course of the 
pipe-line, from Vyrnwy to Oswestry, showed the number of bacteria per c.c. to be at Hirnant, 42 ; 
at Parcuchaf, 28 ; and at Cynynion, 34. 
The number of bacteria in the unfiltered water at Oswestry varied very greatly. Samples 
were collected from various places in the filters above the sand-beds, and it was found, as might be 
expected, that the number of bacteria was far greater in the corners than near the point of entry. 
The highest number of bacteria varied from 700 to 800 per c.c, and probably an average of 50 
per c.c. would be correct. The water in the pipe-line supplying the Oswestry filter-beds 
contained, on an average, 40 per c.c, and it is therefore highly probable that an increase takes place 
in the water standing upon the filter-beds during the filtration process. The average of the 
filtered water as examined at Oswestry was 30 per c.c 
Well W^ai er 
During the year 1898 and 1899 opportunity was taken, when the Green Lane and 
Windsor Wells were emptied, to make a thorough examination of the water issuing from the 
numerous fissures in the side and vault of the wells, and also of the water issuing from the 
bore-holes. 
The examination proved of very great interest. It was found that the number of bacteria 
varied very greatly in the water issuing from the fissures. The highest number was 800 per c.c, 
whilst some samples were sterile. The average for all samples for the Green Lane Well was 134 
per c.c, and that for the Windsor Well 73 per c.c The sand on the bottom of the well was 
subject to a bacteriological analysis and the B. enteriditis sporogenes was found. 
