116 THE HUMAN BODY. 



temperature of about a hundred degrees. Stomachs, how- 

 ever, differ in their ability to withstand cold as much as 

 the outer parts of the body. 



8. Irregularity in eating. The digestive apparatus is 

 subject to habit, like the rest of the system. At the ac- 

 customed meal-time, the saliva and the other digestive 

 fluids will flow, though no food is taken. When that time 

 is passed, they do not start so readily. 



9. Lack of exercise. In a sluggish condition of the body, 

 the digestive juices flow slowly. The alimentary canal 

 does not contract vigorously to knead the food. 



10. In applying these principles, it is to be remembered 

 that one person can do without harm, and sometimes with 

 advantage, what is injurious to another. Men differ very 

 widely in their habits. Each should understand the 

 facts and principles of physiology, and apply them, with 

 the aid of experience, to his own case. 



EFFECTS OF ALCOHOL ON DIGESTION. 



SECTION V. 1. Alcohol irritates the mucous mem- 

 branes. You could not hold it in your mouth; and, if 

 you should swallow any of it clear, your stomach would 

 seem burned. When mixed with much water, as it 

 is in wines and liquors, it is less fiery, and the sensa- 

 tions produced in the mouth and stomach may be agree- 

 able. 



2. It is by this irritant quality that it injures the 

 stomach. In the famous case of St. Martin, the inside of 

 whose stomach could be observed through a wound, Dr. 

 Beaumont found that " the free use of ardent spirits, wine, 

 beer, or any of the intoxicating liquors, when continued 



