156 
J. HOPKINSON-WATER AND WATER-SUPPLY 
upon this vast extent of country, the inhabitants of which are to he 
sacrificed to the presumed needs of this over-grown city. It will, 
I think, come within the province of the geologist to point out not 
only where spring-water of good quality is to he obtained, but also 
what will be the effect of its abstraction upon the districts where it 
now exists in sufficient abundance to overflow into the streams. It 
will be for him to show what will be the effect of producing ‘ a void 
below the level at which the drainage of the country naturally 
escapes; ’ how what are now fertile and even irrigated meadows 
will be converted into arid wastes ; how watercress-beds, now of 
fabulous value, will be brought to the resemblance of newly-mended 
turnpike-roads; how in such a district all existing wells, many of 
them already some hundreds of feet in depth, will be dried, and 
even the canals and navigable rivers become liable to sink and be 
lost in their beds. And these results would, if the scheme were 
carried out, not be confined to some single spot, but would extend 
over hundreds of square miles.” * 
The recommendation of the Commissioners, so strongly deprecated 
by Dr. Evans, it need scarcely be said, has not been acted upon, 
and after the lapse of 20 years we are still drawing the bulk of 
our supply from the rivers which they regarded as in a hopeless 
state of pollution. But are we safe in taking this polluted water ? 
Let us see what our water analysts, William Crookes and Profs. 
Odling and Meymott Tidy, say with regard to the composition and 
quality of daily samples of the water supplied to London by the 
seven water companies taking their supplies from these rivers. Take, 
for example, the Deport to the official Water Examiner for March 
last: in it they say:—“Throughout the month . . . the condition 
of the water furnished to the metropolis by the companies taking 
their supply from the Thames and Lea has continued to be un¬ 
exceptionable.” In that for September, again, they speak of the 
results of their analyses as showing “ an unbroken purity of supply, 
even under the severe conditions consequent on flood and an almost 
unprecedented rainfall. The marked uniformity in the composition 
of the various waters .... is specially noteworthy. Further, the 
complete freedom of the numerous samples examined from any trace 
of suspended matter is to be remarked.” These are fair samples of 
their reports, each of which contains a full analysis of the water 
supplied by all the companies deriving their supply from the Thames 
and Lea.f We are as yet, however, unable to detect the living 
germs of disease by either chemical or microscopical analysis,—at 
least in the stage in which they occur in water,—and we have no 
means of preventing their access to the water of these rivers or 
to the underground reservoir in the Chalk. 
There is little probability now of any proposition being brought 
forward to abandon the Thames and Lea as sources of water-supply ; 
but, as the present supply from all sources is insufficient, under 
the existing methods of distribution, for the constantly-in creasing 
* ‘ Quart. Journ. Geol. Soc.,’ vol. xxxii, (Proc.) p. 116. 
f The Reports were commenced in December, I860. 
