THE STORY OF AN ENTOMOLOGIST 



excreta were dangerous. Further that typhoid must be carried 

 frequently to food suppUes by the flies that swarmed upon these 

 droppings. I made it as strong as I could. 



To my surprise, Dr. Biggs asked Dr. Nuttall if he had any- 

 thing more to say. Nuttall got up in his quiet way and said, 

 as I remember it, "I have studied the housefly and its bacterial 

 flora and content taken in the classrooms at Cambridge and in 

 the college bakehouses and have isolated typhoid organisms 

 from all of them. After these studies, which have been pro- 

 longed, / consider that a single contaminated housefly is a greater 

 source of danger than many gallons of polluted water. What 

 we need in considering this question is not mathematics but 

 common sense!" 



This finished the discussion, and I feel sure that the impres- 

 sion made upon the minds of the large audience was not the one 

 desired by Dr. Chapin. I have often told this story since in 

 lectures, and once, I remember, at one of Graham Bell's Wednes- 

 day Evenings, when Dr. Simmons, long-time secretary of the 

 American Medical Association, and other medical men, were 

 present. I am sure that Nuttall's words have had due weight 

 in the minds of many important men. 



In fact, they often come up in my mind when I am reading 

 some of the rather laborious and possibly far-fetched adaptations 

 of mathematics to other branches of biological science. 



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