46 APPLIED PHYSIOLOGY 



result of using tobacco. The worst effects are that it 

 sometimes causes weakness of the heart and poor sight, or 

 even blindness. These effects will be studied later. 



All these bad effects can be produced in those who 

 breathe the smoke in a room. Babies can easily be made 

 sick by tobacco smoke in a room with them. The young 

 are far more easily poisoned by tobacco than older per- 

 sons. In the young the weakness caused by tobacco is 

 often so great as to hinder the growth of the body. . Boys 

 who wish to grow to be large men had better not use 

 tobacco. In a crowd of boys it is often possible to pick 

 out those who smoke by their smaller size, the thinness of 

 their flesh, and their pale, pasty complexion. 



85. Smoking. Tobacco is used either by smoking, 

 chewing, or as snuff. All tobacco smoke is poisonous, but 

 the stronger the tobacco, the more poisonous it is. The 

 burning also makes poisonous gases, one of which is a 

 dangerous gas like that used in lighting houses. The 

 poisons stay in the stem of a pipe which has been smoked 

 for some time until so much collects that it makes even an 

 old smoker sick. The smoke of a pipe contains more 

 poisons than the smoke of a cigar, for the cigar is more 

 completely burned up. 



86. Cigarettes. Cigarettes are made from mild tobacco 

 and contain less nicotine, yet the danger from using them 

 is still greater, for the smoke is easily drawn deeply into 

 the mouth and often into the lungs, and so more of the 

 poison is apt to reach the cells of the body. 



87. Chewing. Chewing tobacco is a dirty habit which 

 has no excuse beyond the pleasure men learn to take in it. 

 No man who prides himself upon the good looks of his 

 teeth and lips will chew tobacco. It is the most poisonous 

 of all the forms in which tobacco can be used. 



