70 Dr. Edivard FranUand [Feb. 21, 



upwards from the Burface of the comparatively clear water. It cannot, 

 therefore, excite surprise that the effect of sunshine upon bacterial 

 life in the great mass of Thames water should be nearly if not 

 quite imperceptible. We have thus ascertained that sunlight can 

 only^kill the germs or microbes near the surface of the water, whilst 

 those at any depth for the most part escape destruction. 



On the other hand the enormous effect of floods in augmenting 

 the number of microbes can hardly surprise us; for when a great 

 body of water has flowed over the banks of the river, which are at 

 other times dry and exposed, carrying along with it countless im- 

 purities — an effect common both to the main stream and its tributaries 

 — the Thames basin is, as it were, on every such occasion, thoroughly 

 washed out, and it is only to be expected that the number of microbes 

 in the water should be enormously increased, as is found to be the 



The Water Supply of the Future, 



In view of the rapid increase of the population of London, fears 

 have, from time to time, been entertained that the water supply from 

 the Thames basin, that is to say, from the rivers Thames and Lea 

 supplemented by water from springs and deep wells within the basin 

 itself, would soon be insufficient in quantity ; whilst the quality of 

 the water taken from the rivers has, up to a comparatively recent 

 date, been considered unsatisfactory. On these grounds various 

 schemes have, from time to time, been brought forward for the 

 supply of the metropolis from other river basins — from the Wye, the 

 8evern, the river basins of North Wales, and of the lake districts 

 of Cumberland and Westmoreland. It is worthy of note, however, 

 that all the Koyal Commissions have arrived unanimously at the 

 conclusion, that the quantity of water obtainable from the Thames 

 basin is so ample as to render the necessity of going elsewhere a 

 very remote contingency. 



I shall now endeavour to put very shortly before you the facts 

 which, in my opinion, prove that, both as regards quantity and 

 quality, the Thames basin will, for a very long time to come, afford 

 an abundant supply for the metropolis. There is, indeed, no river 

 basin in Great Britain which aftbrds such an abundant supply of 

 excellent water as that available in the Thames basin. 



Besides that which flows directly into the river, this water is 

 contained in the chalk, oolite and lower greensand, which are the 

 best water-bearing strata in the kingdom. From these strata it 

 issues in copious springs of unsurpassed organic purity. I have 

 personally inspected every spring of importance in the Thames basin, 

 and have analysed samples of the water. The results, in a very 

 condensed form, are recorded in the following table : — 



