BACTERIA AND HEALTH 



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see the interdependence of people, living it may be at considerable 

 distances from each other or in different states. 



Because there is not yet any adequate control over the habits of 

 those who dwell in the country, in the matter of disposing of house 

 soil, garbage, etc., it is important for those who dwell in cities that 

 their water supply be properly guarded, if not at the source, then 

 through suitable filtration or sterilization. All these activities, and 

 many others, suggest how human life is constantly influenced and 

 modified by the activities of these minute yet significant organisms. 



1905 



1906 



1907 



1908 



1909 



1910 



1911 



1912 



1913 



1914 



1915 



1916 



1917 



' FIG. 204. The reduction of infant mortality in New York City 



This diagram shows, month by month, for a period of thirteen years, the proportion of 

 infants (under one year old) who died to the infants born. There is a variation from 

 month to month, with a very striking increase in the number of deaths during the 

 summer months. When the records showed this big jump in 1905, physicians and 

 nurses and sanitary experts at once took steps to discover the causes and to devise 

 preventive measures. Year by year we can see a steady improvement. So much effort 

 has been made to protect the children for the bad month of July, that in recent years 

 this month has showed off rather better than the others, and August and September 

 have become the bad months. With increased knowledge, and especially with wider 

 application of the knowledge we already have, the high points on these black spots will 

 be cut down, and the general level of the spots will be considerably lowered. This is but 

 another way of showing that applied biology saves hundreds of thousands of lives 



