76 Physiology. 



the sympathetic nerves on the muscles in the walls of the 

 arteries. If there is more blood in the skin, there must be 

 less somewhere else at the same time. Now this is what 

 makes a mustard plaster useful. When there is congestion 

 or inflammation in some internal organ, a mustard plaster 

 applied to the outside draws away some of the blood and 

 thus affords relief to the congested part. 



The Hot Foot Bath. When one has a cold, a hot foot 

 bath relaxes the arteries of the feet. This is a good means 

 of drawing the blood away from internal organs, and often 

 saves the person from serious or even fatal results from 

 a bad cold. 



Effect of Alcohol on Circulation in the Skin. The warm 

 and flushed condition of the skin which follows the drink- 

 ing of alcoholic fluids is due to interference with the nerve 

 center that has control of the muscles in the walls of the 

 arteries leading to the skin : the' circular muscles are no 

 longer made to shorten, and the artery dilates, thus allow- 

 ing more blood to flow into it. We may thus account for 

 the flushing of the face, which in many individuals quickly 

 betrays indulgence in alcoholic drink. If this flushing is 

 too often repeated, the arteries gradually "lose tone," and 

 the condition becomes permanent. The circulation in 

 the whites of the eyes may be affected, making them 

 "bloodshot." 



General Effect of Alcohol on Circulation. The general 

 effect of alcohol on the circulation is well illustrated by 

 the effect on the skin. The muscles in the walls of the 

 arteries relax because of the paralyzing effect of alcohol 

 on the nerve centers controlling these muscles. Every- 

 where in the body alcohol tends to cause a flushed con- 

 dition. To tell all about this would be to take up digestion, 



