320 APPLIED PHYSIOLOGY 



sucking smoke through a pipe. In fact, smokers often 

 cannot tell by the taste alone, whether the pipe or cigar is 

 alight or not; but they unconsciously judge mainly by see- 

 ing the smoke. Since tobacco weakens the heart, less 

 blood will flow through the body when tobacco in any 

 form is used, and this fact will tend to make the mind act 

 less strongly than before. The nicotine is also a direct 

 nerve poison. 



586. Drug habits. Opium, cocaine, and other narcotic 

 drugs whose use may become a habit, affect the mind in 

 the same way as alcohol. Every one who habitually uses 

 any of these drugs will surely become a mental as well as 

 a physical wreck. Opium, especially, seems to have a 

 fiendish effect in destroying the morality of its users. 

 They begin by lying and cheating in order to obtain the 

 drug without the knowledge of their friends, and they 

 finally end by becoming dishonest in all things. But the 

 drug produces a weak mind and body which soon end in 

 death. Most of these drugs are far more dangerous than 

 tobacco or alcohol. 



587. Ether and chloroform anaesthesia. Ether and chloro- 

 form are both substances manufactured from alcohol. When they are 

 breathed into the lungs they produce effects which resemble a rapid 

 state of drunkenness carried to its last stage. For a brief time, the 

 brain is excited and then its faculties disappear one after another. In 

 from five to fifteen minutes the brain and spinal cord are completely 

 overcome, and only the medulla continues in action to carry on respira- 

 tion and the circulation of blood. A person may be safely kept in this 

 condition for two or three hours. Upon stopping the inhalation the 

 effects pass off in reverse order, until in from ten minutes to an hour 

 one has the full use of his brain again. The thought regions are over- 

 come long before the motor regions, and so a person taking ether may 

 struggle and cry out in apparent agony long after he has become com- 

 pletely unconscious. The struggling is reflex and takes place while a 

 person is insensible to suffering. 



