THE MIDDLE LIAS OF NORTHAMPTONSHIRE. 
37 
It is a characteristic of these land springs that they vary 
considerably with the seasons, botli in quantity and quality, 
and in dry seasons frequently fail altogether, for the double 
reason that the accumulation of water is not large, and they 
are not without the influence of the evaporative power of the 
sun aided by capillarity and vegetation. The quality of the 
water from such springs is sometimes satisfactory, but much 
more often decidedly bad. In the particular case under 
consideration, this source of supply may be condemned for 
several reasons. (1.) The river gravel is either not at all, or 
only slightly, overlaid by impervious matter, and so the water 
is easily contaminated from the surface; besides this, one of the 
main sewers of the town passes through a portion of this bed, 
not very far from the situation once proposed for a pumping 
station, and so at any time the water might have become 
contaminated with the most dangerous of all impurities. 
(2.) The water is so near the surface and the bed so 
inconsiderable in thickness that it cannot itself vield water 
* _ «/' 
sufficiently well filtered for domestic use. The general 
character of the water will be seen from the following 
analvsis, which must be taken as a mean of several:— 
t / 7 
Solids 
Chlorine 
Nitrites 
Nitrogen in nitrates and nitrites ... 
Free ammonia 
Albuminoid ammonia 
72 grains per gallon. 
6*2 do. do. 
A little. 
2-5 do. . do. 
•31 parts per million. 
•18 do. do. 
The solid residue charred a little on being heated, and during 
the operation emitted the disagreeable odour characteristic 
of ignited organic matter. (3.) The water is not sufficient in 
quantity for a town supply. I know of one instance in which 
rather continuous pumping at one well drained another about 
a quarter of a mile away in a very short time—a day or two— 
and, of course, any contamination would be all the more 
injurious because of its comparatively small dilution. 
This water was for a time used for flushing purposes, and 
this was, of course, a very legitimate use for it when better 
water was very scarce. 
It may be said in favour of this water that it is well 
clarified, and rather bright and sparkling in appearance. 
The bed seems to offer considerable facilities for the oxidation 
of organic matter, owing to the fact that there is considerable 
variation in the water level with the season, and each time 
