TOBACCO IN RELATION TO HEALTH 67 



Thirdly, the presence of ammonia can be detected in small 

 quantity, and this gives to the smoke an alkaline reaction 

 that bites the tongue after long smoking ; it is the ammonia 

 that makes the tonsils and throat of the smoker so dry 

 and induces him to quaff as he smokes, and that partly 

 excites the salivary glands to secrete so freely. This 

 element also exerts an influence on the blood. Fourthly, 

 the test of lime-water applied to the leaf shows the 

 presence of carbonic acid. In the smoke the quantity 

 differs considerably in different kinds of tobacco ; to the 

 action of this constituent Sir B. W. Richardson traces the 

 sleepiness, lassitude, and headache which follow upon 

 prolonged indulgence of the pipe. Fifthly, the smoke of 

 tobacco yields a product having an oily appearance and 

 possessing poisonous properties ; this is commonly known 

 as nicotine, or oil of tobacco, which on further analysis is 

 found to contain three substances, namely, a fluid alkoloid 

 (the nicotine of the chemist), a volatile substance, having 

 an empyreumatic odour, and an extract of a dark resinous 

 character, of a bitter taste. From this comes the smell 

 peculiar to stale tobacco which hangs so long about the 

 clothing of habitual smokers if the smell be from good 

 Eastern-grown tobacco many persons think it wholesome. 

 It is nevertheless this extract which creates in those unac- 

 customed to its use a feeling akin to sea-sickness. Hence 

 it appears that the more common effects are due to the 

 carbonic acid and ammonia liberated in the process of 

 smoking, while the rarer and more severe symptoms are due 

 to the nicotine, the empyreumatic substance, and the resin. 

 As to the effects of tobacco-smoking upon the human 

 body Sir Benjamin Richardson would appear to see no 

 reason for thinking that it can produce any organic change, 

 though it may induce various functional disturbances if 



