78 CONSCIOUS NERVOUS OPERATIONS 



or entered upon indifferently and listlessly is found to 

 have little or no invigorating power. 



103. Effect of Alcohol and Other Stimulants and Narcotics 

 upon Muscular Action. The most serious effects of the 

 excessive use of alcoholic drinks, tobacco, opium, chloral, 

 and other narcotic drugs are felt by the nervous system 

 and will be most fully treated when we come to the special 

 study of that part of the human organism. But it is well 

 to notice here how those substances influence the organs 

 of motion. 



No one who has ever seen a drunken man in the stage pre- 

 ceding that of stupor can have failed to observe the uncer- 

 tainty of his muscular movements : the shaking hand, the 

 staggering gait, the thick, indistinct utterance. These 

 effects are due to what is called the excessive use of alco- 

 holic drinks, and no one doubts that in large quantities 

 they act injuriously upon the system. Alcohol deranges 

 the action of the muscles by its influence upon the nervous 

 system, causing defective regulation of the supply of nerv- 

 ous force to the several muscles. As to whether it is pos- 

 sible to use alcohol in small amounts without impairing 

 the perfection and vigor of muscular action, there is one 

 very significant fact: that men in training for severe mus- 

 cular exertion in athletic contests are strictly forbidden 

 the use of alcohol in any form and in any quantity, 

 whether or not they have been previously accustomed to 

 such indulgence. As. the rules for such training are the 

 result of long and wide experience and most careful study, 

 it is safe to conclude that alcohol at least does not promote 

 strength, endurance, or precision of muscular movement. 



It is very common for a person accustomed to a moder 

 ate use of alcoholic beverages to suffer from tremor of the 

 hands, due to lack of control over the muscles, so that 



