THE PREVENTION OF INFECTIOUS DISEASE. 423 



are able now in every case to close the well 

 before the child has fallen in ; we need not delay 

 action until an epidemic makes its appearance. 

 In 1892 Hamburg was scourged with cholera 

 for its negligence about water-supply, yet that 

 harmful consequences were likely to flow from 

 this neglect had long been predicted by all 

 physicians and technologists capable of judg- 

 ing in the matter. Applied correctly and sen- 

 sibly bacteriology is certainly able to assist our 

 insight into such questions and a science of 

 hygiene minus bacteriology is simply impossi- 

 ble. In our estimation of external conditions 

 according to their ability to spread infectious 

 disease, bacteriology has afforded great service, 

 and our former inability to judge of these rela- 

 tions from the standpoint of the possibility or 

 impossibility of infection has already given way 

 to a true advance in the direction of a prac- 

 tical preventive hygiene. To be sure, little 

 legislative attention has yet been paid to 

 this point, and the legal regulation of the water 

 question which was urged by me at the inter- 

 national congress of hygiene in Vienna in 

 1887 still remains unaccomplished in spite of 

 the fact that I brought up the matter anew in 

 London in 1891 and in Budapesth in 1894, 

 and again proved that such regulation could 

 be enforced. The sentiment that attaches 



