THE QUAETEKLY 



JOURNAL OF SCIENCE 



JULY, 1867. 



I. THE WATEE SUPPLY OF LONDON, AND THE 

 CHOLEEA. 



By E. Frankland, F.E.S., Professor of Chemistry in the Eoyal 

 Institution of Great Britain and in the Eoyal School of Mines. 



The growth of nearly every large town has involved a succession of 

 struggles for the supply of its -inhabitants with pure water. Even 

 the aggregation of a few houses forming a village not unfrequently 

 causes a sensible pollution of the water supply, if the wells be suffi- 

 ciently shallow. As the village develops into a town, the water 

 from such sources not only becomes dangerous from impurity, but 

 also totally insufficient in quantity for the increasing population. 

 Eecourse is then had to a neighbouring stream for a purer and 

 more copious supply ; but greater abundance of the useful liquid 

 determines the production of a larger volume of sewage, part of 

 which, as the town extends itself along the banks of the stream, 

 begins to be discharged above the point at which the water supply 

 is withdrawn. Contamination again ensues, and the place of with- 

 drawal is removed higher up the river. Belief is thus obtained, 

 but it is only temporary ; villages nearer the source of the stream 

 grow into small towns, and the struggle is only terminated by 

 seizing upon and impounding the very sources of the stream itself, 

 by which alone a permanently wholesome and untainted beverage 

 can be secured. Such is the history of water supply in most large 

 towns, and such is, or must be, its history in the English capital. 

 Another visitation of the most terrible epidemic to which modern 

 London is still subject hss once more called earnest attention to the 

 serious defects of the metropolitan water supply. It will require 

 much acute observation and laborious experimental research before 

 the origin and spread of cholera will be thoroughly understood ; but 

 there are certain prominent features in the character of this epidemic 

 which at once arrest attention and at least suggest the direction in 



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