November 18, 1004.] 



SCIENCE. 



663 



in the tissues of those individuals able to 

 live an outdoor life. 



It is evident that in the case of tubercu- 

 losis the forces of civilization are on the 

 whole vs^orking- for its extinction rather 

 than for its perpetuation. The available 

 statistics demonstrate that before the mod- 

 ern movement for the suppression of the 

 disease began, and, in fact, even before the 

 discovery of the tubercle bacillus, con- 

 sumption was already on the decline in 

 widely separated parts of the world — in 

 London, in Boston and in Chicago. It is, 

 perhaps, significant that consumption is 

 now one of the tenement house problems 

 and that as such it occupies a strictly de- 

 limited field. As yet the campaign against 

 tuberculosis has been a desultory one, 

 waged by a few enthusiasts without ade- 

 quate material or moral support on the 

 part of the community at large, but signs 

 are multiplying that this condition will 

 be a transient phase. The comparative 

 absence of intelligent, systematic endeavor 

 for the suppression of disease is certainly a 

 curious phenomenon in an age of other- 

 wise extensive coordination and organized 

 action. The executive talents and re.stless 

 energy lavished on commercial, industrial 

 and engineering projects may some day be 

 turned to devising and carrying out hy- 

 gienic measures. If it were necessary to 

 find an argument in the economic value of 

 human life it would be readily forthcom- 

 ing. The recent movements for the study 

 and suppression of tiiberculosis mark one 

 of the first attempts to apply bacteriolog- 

 ical knowledge in a determined and radical 

 way to a problem of public hygiene. As 

 regards the ultimate extinction of tuber- 

 culosis, there may be more or less groping 

 after ways and means, but there need be no 

 misconception as to the scope of the 

 problem. 



There are other fields where a similar 

 mode of procedure based on ascertained 



bacteriological facts and principles has 

 been indicated and is being at least in part 

 carried out. In typhoid fever the evidence 

 from epidemiology has long pointed unmis- 

 takably to drinking water as being the 

 chief vehicle of infection, and the first step 

 towards suppression of this disease has 

 been already taken in most civilized coun- 

 tries. The last half of the nineteenth 

 century witnessed an improvement in the 

 sanitary quality of public water-supplies 

 which has diminished perceptibly the death 

 rate from typhoid fever. This change has 

 been in part effected by the introduction of 

 water from unpolluted sources, in part by 

 the installation of sand filters. To cite a 

 few well-known cases. For five years before 

 the introduction of a filtered water the 

 annual typhoid fever death rate in Zi;rich, 

 Switzerland, averaged 76 ; in the five years 

 following the change it averaged 10. In 

 Hamburg, Germany, for a corresponding 

 period before filtration, the typhoid death 

 rate was 47 ; after the change it fell to 7. 

 In Lawrence, Massachusetts, under similar 

 conditions the typhoid rate M'as reduced 

 from 121 to 26, and in Albany, N. T., from 

 104 to 38. A similar effect has been no- 

 ticed where an impure water has been re- 

 placed by water from unpolluted sources. 

 In Vienna, Austria, the abandonment of 

 the River Danube as a source of supply in 

 favor of a ground water diminished the 

 typhoid fever death rate from over 100 

 to about 6. In the United States, the city 

 of Lowell not long ago exchanged the pol- 

 luted water of the Merrimae River for a 

 ground water supply, with the result that 

 the typhoid fever death rate was reduced 

 from 97 to 21. In spite of the remarkable 

 facts there has been a lethargic slowness 

 in profiting by the lessons that they teach. 

 Many communities have remained to this 

 day imobservant and negligent, and, es- 

 pecially in the United States, the condi- 

 tion of the average public water supply 



