76 HUMAN BIOLOGY 



composition of protoplasm. During the whole period in 

 which the body is attaining its growth this living substance 

 is affected far more appreciably and seriously by the use 

 of stimulants and narcotics than is the case later in life. 



Tobacco is a narcotic in its effects; that is, it tends to 

 decrease activity and likewise growth. That such is its 

 effect during early life has been abundantly proved in 

 many ways. But perhaps the most conclusive facts are 

 those presented by actual measurements made in college 

 gymnasiums. Dr. Hitchcock, of Amherst College, who has 

 made careful measurements of college students for a good 

 many years, 'finds that those who do not smoke increase in 

 height during their college course 37 per cent more than those 

 who do smoke, and in chest girth this difference is 42 per cent, 

 or nearly one half as much again. Dr. Seaver of the Yale 

 Gymnasium finds, also, that in height and lung capacity 

 smokers are considerably inferior to those who do not use 

 tobacco. 



103. Effect of tobacco on mental development. Dr. 



George L. Meylan, Director of the gymnasium of Columbia 

 University, made a careful comparison during two years of 

 the relative physical measurements, rate of growth, and 

 scholarship of 115 college men who smoked and 108 men 

 in the same class who were non-smokers. 1 He found 

 (1) that the smokers were on the average eight months 

 older, which means that they had entered college this much 

 later ; and (2) that " the scholarship standing of smokers 

 was distinctly lower than that of the non-smokers," showing 

 " that the use of tobacco by college students is closely asso- 

 ciated with idleness, lack of ambition, lack of application, 

 and low scholarship." 



1 Popular Science Monthly, August, 1910. 



