62 PUBLIC HEALTH 



longed life in, and ready conveyance by, public water-supplies, 

 and (2) as a promising possibility, that as the result of the greater 

 purity of the water-supply the physiological resistance of the con- 

 sumers of pure water-supplies is enhanced, in some manner as yet 

 unknown; the net result being that the general death-rate is lowered 

 to such an extent as to lead to a rapid increase of population in 

 communities previously stationary or multiplying far less rapidly. 

 In the case of the city of Lawrence, Massachusetts, for example, 

 I have recently had the privilege of examining the results of studies 

 by the distinguished hydraulic and sanitary engineer, Mr. Hiram F. 

 Mills, which show that since the introduction of a municipal filter, 

 which purifies the water of the Merrimac River supplying water 

 to the citizens of Lawrence, while the population has increased 

 nearly seventy per cent, the total number of deaths remains about 

 the same as it was ten years ago. Mr. Mills concludes from the 

 results of his studies and I see no escape from his conclusions 

 that the introduction of the municipal filter has not only saved 

 the lives of thousands of citizens, but has also caused the popula- 

 tion to increase to a point much beyond any which it would have 

 reached had the city continued to use, unpurified, the sewage- 

 polluted water of the Merrimac River. A demonstration of this 

 sort shows how easily the diminishing increase of population under 

 .a lower birth-rate may sometimes be counteracted without resort 

 to that fish-like spawning which seems to be the only remedy of 

 those who are terrified by "race suicide," so called. Moreover, it 

 is hardly necessary to point out that such a diminishing death-rate 

 means a far more rapidly diminishing morbidity rate in other 

 words, it means a heightened working efficiency of the population 

 as a whole, and it must not be forgotten that for most of the re- 

 sults obtained in the scientific purification of water-supplies we are 

 indebted to the science of engineering. 



On the other hand, we must observe that engineering science, so 

 far as Avater purification is concerned, is as yet only in its infancy 

 and by no means thus far altogether satisfactory. In the United 

 States, for example, in the last two or three years a number of epi- 

 demics of typhoid fever have resulted from the defective operation 

 or construction of municipal filters, and while much has been done, 

 it is clear that much still remains to do. In this connection it should 

 be said that public health science in the United States suffers con- 

 stantly and severely from an unsatisfactorjr condition of the science 

 and art of administration or government in many American cities. 

 Public health works are too often neglected, delayed, mismanaged, 

 or built at extravagant cost, to the sanitary and economic damage 

 of the people as a whole, and the tendency is far too common to 

 place the care andToperation of costly devices or systems in incom- 



