424 BIOLOGY AND HUMAN LIFE 



ought to be tolerated, but it is just as well for us to know what it is that 

 yields the enjoyment. Generally speaking, then, it is not the effect of 

 the nicotin. Very often, especially with young people, it is the feeling 

 that they are doing something wonderful — like grown folks ! In many 

 cases it is the sight of the curling smoke ; this has its fascination no 

 matter what the source of the smoke may be, and many experienced 

 smokers assert that they cannot enjoy a smoke in the dark. In many 

 cases the satisfaction really comes from the handling of the cigar or pipe, 

 working it about with the muscles of the lips and tongue, and so on ; 



many a smoker has enjoyed 



I 05 Non-smokers t$j>^ hls smoke vcry much until 



he suddenly discovered that 



, — -— ,^ ^^■ ■ ,^^vvvvsv^^«AV-v.vv>k.^s^- r -^' V v^.^ 0^1 he had forgotten to light the 



1 10 >on. smokers t>>:s^fxStAyMQ^Sm;oke^g^?^<y.^^^y-^^^^ ° ° 



tobacco. Here the tobacco 

 Fig. 175. Smoking and scholarship flight just as well have 



Showing the proportion of smokers (shaded been replaced with a Stick 

 space) and of non-smokers (white space) among of chewing gum or the 

 the students of highest rank (first bar) and u u ' -f. 



among students of ordinary rank (second bar) at DaDy S pacmer. 

 Yale University. In several colleges records show On the other hand, it 



that in any given graduating class the smokers ^lUSt be said that, for those 

 are on the average older than the non-smokers. u j i. 1 i.i- j 



This may show the extent to which smoking ^^'^0 do not smoke, the odor 

 — perhaps in association with other unhygienic of the smoke and the spoil- 

 habits — retards a young person in his progress jng of the air are real impo- 

 sitions. As David Starr 

 Jordan said, ''We ask a free passage through the world, with pure air 

 all the way.'" Of all the fires in this country, more are caused by the 

 careless smoker than by any other one thing. As for the smoker himself, 

 there is evidence of (i) interference with digestion, (2) chronic irrita- 

 tion of the linings of the air passages and lungs, (3) disturbed heart 

 action, (4) bad effects upon the nerves, (5) stunted growth (Fig. 173), 

 and (6) disturbances of the eyes. These effects of smoking need not all 

 appear in any one person ; and it is quite possible that they are not 

 always due to the nicotin, of which only a very small portion, at the 

 worst, enters the system. Poor scholarship among high-school students 

 (Fig. 174) and college students (Fig. 175) may involve other factors 

 besides smoking. 



In many parts of the world the natives make use of various 

 materials containing some alkaloid to help them forget their 

 troubles or, as they suppose, to increase their joys. In many 

 cases these substances tend to break down the control which 



