BACTERIOLOGY AND WATER 101 



taken, and indeed required by the Royal Com- 

 missioners of 1893 on the London water-supply, 

 indicates clearly enough the change which has 

 taken place in the public estimation of the value 

 of these methods ; and it is highly significant that 

 in their report the Commissioners lay stress upon 

 the importance of extensive storage and efficient 

 filtration, two factors the meaning and worth of 

 which rest almost entirely on the results of 

 bacteriological research. 



Cholera is not, however, the only water-carried 

 disease which has borne eloquent testimony to 

 the services rendered by the efficient purification 

 of public water - supplies. The experience of 

 the State of Massachusetts in America, in regard 

 to typhoid fever and drinking-water, is also ex- 

 ceedingly instructive. 



Massachusetts has, by creating a Board of 

 Health, and affording the same every facility 

 for the prosecution of hygienic investigations of 

 the greatest importance, laid the whole scientific 

 world under a deep obligation. The reports 

 issued have a very wide circulation, and embrace 

 a variety of subjects, but second to none in 

 interest and importance is the account of the 

 experimental work carried out by the officials of 

 the Board on the purification of water and sewage. 

 These experiments have become classical, and 



