68 



MAN THE ANIMAL 



that are not, in themselves, necessary to the maintenance of life 

 as is food. Is the smoking of tobacco associated statistically with 

 any impairment of the normal expectation of life, or with an 

 improvement of it, or is there no measurable association one 

 way or the other? This question, too, has excited controversy, 



loojaco 



dA(XV 



iS ^ 45 SH iS (a 6S 70 75 60 £} 



A^ in Years 



90 95 100 



Fig. 11. The number of surviving- males out of 100,000 starting together at age 



30, in three drinking categories: (a) abstainers (solid line), (b) moderate 



drinkers (dash line), and (c) heavy drinkers (dot line) 



though not so violent as that over alcohol. It is the intention to 

 present now a small part of the results of a statistical investiga- 

 tion of this problem. The data were collected at first hand. Their 

 accuracy as to the relative degree of habitual usage of tobacco, 

 and as to the ages of the living at risk, and of the dead at 

 death can be guaranteed. The figures to be presented deal only 

 with white males, and with the usage of tobacco by smoking. 



