BACTERIOLOGY AND WATER 103 



respect of typhoid - mortality being coincident 

 with the improvement made during the last 

 twenty years in providing public water-supplies. 

 In the words of one of the State reports, " The 

 death-rate from typhoid fever has generally fallen 

 as the per cent, of the population supplied with 

 public water has risen, for the reason that the 

 majority of the deaths from this disease have 

 occurred among communities and portions of 

 communities not supplied with public water? 



That this improvement is being maintained is 

 seen from the fact that in the four-year period 

 1896-99 the deaths from typhoid fever in Massa- 

 chusetts were further reduced to 2'6 per 10,000. 



It is, however, in the city of Lawrence that the 

 most striking insight is obtained as to the manner 

 in which typhoid fever may be controlled by 

 conditions surrounding the water-supply to the 

 community. Thus, whereas the death-rate from 

 typhoid fever reached a mean of 11*2 per 10,000 

 in 1886-90, it fell to 77 in 1891-95 and to 2-5 

 in 1896-99. It was in the autumn of the year 

 1893 tnat the raw river- water supplied to the 

 city from the Merrimac River was first begun 

 to be filtered, and since that time the sand- 

 filters have been subjected to systematic and 

 most elaborate bacterial supervision, and im- 

 provements have been constantly introduced so as 



