PAPERS ON MEDICINE AND PUBLIC HEALTH 461 



warns against repeated doses of bacteriophage since 

 these make animals hyper-susceptible and a greatly re- 

 duced amount of infection is required to produce death. 

 Bacteriophage is interesting from a public health 

 standpoint. ^Vhile it is not permissible to theorize on a 

 subject which can be settled only by scientific research, 

 yet there are some matters of particular interest to which 

 I wish to call attention. Do persons become ill because 

 of lack of bacteriophage and recover when this principle 

 is activated or when it is supplied artificially, as by in- 

 gestion? Is the higher mortality among the primitive 

 races accounted for, in tuberculosis for instance, be- 

 cause of the lack of bacteriophage against tuberculosis? 

 And is the greater resistance of the so-called civilized 

 races to tuberculosis due to the fact that the population 

 in general has imbibed more or less freely from each 

 other of bacteriophage principles? In the self puri- 

 fication of streams polluted by sewage, does bacterio- 

 phage have any part in destroying the intestinal organ- 

 isms? From the observations of Hankin in India, it 

 would appear that this is so. These are only a few of the 

 problems of public health which are before us to be 

 worked out. 



