254 ELEMENTARY BIOLOGY 



are by no means a fair indication of what he is actually 

 accomplishing. 



It is well known that in larger quantities alcohol has a de- 

 pressing effect upon the nervous system, lowering the acuteness 

 of the senses, weakening the attention, deranging the judgment, 

 and leading to sleepiness. It is only the feeling of elation and 

 alertness, which comes shortly after taking the small quantity 

 of alcohol, that deceives the drinker ; for the after-effect of a 

 small quantity is of exactly the same kind as the earlier effect of 

 a large quantity. This is the chief danger in the use of alcohol. 

 Like the rabbit that has been taking arsenic, the person who 

 drinks alcohol produces in himself two peculiar results : 



1. He must have more and more, as time goes on, to pro- 

 duce the same effect that a small quantity was sufficient to 

 produce at first. 



2. He gets to the point where he feels that he cannot live 

 without the alcohol : and, indeed, there are many people who 

 really suffer a great deal from the lack of alcohol, no matter 

 how much more they suffer when they have it. 



It was formerly quite a common thing for physicians to apply 

 alcohol in cases that required a heart stimulus for a short time, and 

 in other cases. But since careful measurements have shown that the 

 advantageous effects of the stimulant are largely offset by the re- 

 action, and since it has been found that much of the stimulation is 

 only apparent, and not real, physicians are coming to use alcohol 

 as a medicine less and less. And in some hospitals it is never used 

 internally, except where necessary for the administration of some 

 other drug. 



307. Coffee and tea. Next to food drinks and intoxicating 

 drinks the most common beverages are tea and coffee. These 

 drinks are prepared for the aromatic flavor and for the slightly 

 stimulating effects produced by an alkaloid which they contain. 



The leaves of tea and the seeds of coffee contain the same 

 alkaloid, caffein. In a pure state this is poison, even when 

 taken in small amounts. In the small quantities taken with 



