172 THE POPULAR SCIENCE MONTHLY 
The effect of nicotine on the growth is very measurable, and the following 
figures are presented as a fairly satisfactory demonstration of the extent of the 
interference with growth that may be expected in boys from sixteen to twenty- 
five years of age, when they are believed to have reached full maturity. For 
purposes of comparison the men composing a class in Yale have been divided 
into three groups. The first is made up of those who do not use tobacco in any 
form; the second consists of those who have used tobacco regularly for at least 
a year of the college course; the third group includes the irregular users. 
A compilation of the anthropometric data on this basis shows that during the 
period of undergraduate life, which is essentially three and a half years, the 
first group grows in weight 10.4 per cent. more than the second, and 6.6 per 
than the second, and 11 per cent. more than the third; in girth of chest the 
first group grows 26.7 per cent. more than the second, and 22 per cent. more 
than the third; in capacity of lungs the first group gains 77 per cent. more 
than the second, and 49.5 per cent. more than the third. 
These figures have been widely quoted, and generally considered as 
affording positive proof that college students who do not use tobacco 
make far greater progress in physical development than is the case 
with smokers. Without actual figures of increment in measurements, 
these percentages signify little or nothing. For instance, the difference 
of 24 per cent. in stature increment reported might mean that the 
smokers increased 17 millimeters and the non-smokers 21 millimeters, 
but no one would attach any significance to a difference of 4 millimeters 
in stature measurement. 
A recent study by E. L. Clarke, published in the Clark College 
Record for July, 1909, shows that 46.3 per cent. of 201 students smoke. 
The smokers exceed the non-smokers a little in strength and lung- 
capacity, and 26 per cent. of the smokers won athletic insignia against 
16 per cent. of the non-smokers. But in the matter of scholarship, 
68.5 per cent. of the non-smokers won honors as against only 18.3 per 
cent. of the smokers. Mr. Clarke concludes: 
1. As a rule the non-smoker is mentally superior to both the occasional 
and the habitual smoker. : 
29. As a rule the non-smoker is equal, and probably slightly superior, phys- 
ically, to all members of the smoking classes except the athletes. It may well 
be queried as to whether the smoking athlete does not make his gain at too 
high a mental cost to make it pay. No one would contend for a moment that 
smoking is the sole cause of these differences. There are numerous other factors 
that are inseparably linked with it. 
The question may be approached from the physiologic, the moral 
or the economic view-point. In this article, the chief aim will be to 
determine if smoking exerts any influence upon the physical and mental 
characteristics of college students; the moral question involved will be 
considered only incidentally; no attempt will be made to present the 
economic view-point. ‘The writer, with the cooperation of his assistant, 
Mr. Hyman Cohen, A.M.., made a detailed study of 223 college students 
from two classes, including all for whom records could be obtained. 
