TOBACCO 299 



Presence of carbon monoxide (CO). In smoking, 

 there are added to the effect of the drug itself the fumes 

 from the ingredients of the tobacco other than the nico- 

 tin, and these are also absorbed into the system. It 

 is supposed that one of these, carbon monoxide, gener- 

 ated because of the low temperature at which the to- 

 bacco is burned, is responsible, in part at least, for the 

 great weakness and deranged heart action which con- 

 firmed smokers, especially of cigarettes, experience. 



Extent of use. The extent to which tobacco is used 

 is much more important from the standpoint of health 

 than the mode of its use. As in other narcotics, the 

 habit grows fast with repetition. As the habit strength- 

 ens, the size of the dose required to satisfy the desire 

 tends to increase. Owing to the adaptation of the body 

 to its influence, a dose which in the beginning would 

 cause nausea, headache, dizziness, prostration and even 

 death, is often required after a year or two of use to 

 satisfy the daily craving for it. Although the bad 

 effects of its use have thus become less apparent, it 

 cannot be said that they have ceased. Irritation of the 

 mucous membrane lining the throat and mouth, more 

 or less dyspepsia, increased nervous irritability and im- 

 pairment of the heart action are very apt to accompany 

 its persistent use, especially in young persons. 



Individual susceptibility. The injury which the use 

 of tobacco causes varies greatly with individuals, some 

 being much more susceptible to its use than others. This 

 holds true, however, only of those who have passed the 

 developing period. During youth, all are highly sus- 

 ceptible to it. The poison of tobacco is especially injuri- 

 ous to the developing nervous system, the heart and 

 blood-vessels, the lungs and stomach. It not only inter- 

 feres with their growth but even tends to exert first 



