284 INOEGANIC AGENTS 



walls of the stomach and perverts the normal secretion into a 

 mucous discharge. Alcohol is slightly astringent in the di- 

 gestive tract, and may relieve pain by its local anaesthetic 

 action upon the stomach, and spasm, by stimulating the 

 nervous mechanism controlling the stomach and bowels, and 

 so co-ordinating the peristaltic movements. 



Circulation. — A tremendous change in the position and 

 practice of the profession in regard to the stimulant action 

 of alcohol has been wrought by the accumulating evidence 

 of experimenters. It is no longer regarded as a heart stim- 

 ulant from a physiological standpoint although in disease 

 it has not altogether lost its reputation in this respect. At 

 present it is impossible to explain this contradictory condi- 

 tion. 



The reason for the supposition that alcohol is a heart 

 stimulant was based on its action in increasing the pulse 

 rate in man. In animals diluted alcohol does not affect 

 either the rate or force of the heart, except in poisonous 

 closes, when the pulse is slowed and weakened owing to 

 weakening of the cardiac systole and dilatation of the heart 

 cavities. In man the increased pulse rate is attributable to 

 muscular and mental activity produced by alcohol. 



The blood pressure is not materially altered by medic- 

 inal _doses of alcohol. There is, however, marked dilatation 

 of peripheral vessels following the use of alcohol, as seen 

 in the ilushing of the face in man. 



Whether this is due to action on the central or periph- 

 eral vasoinotor system is unknown. The dilatation of vessels 

 is certainly not general or blood pressure would be lowered. 

 But there is a redistribution of blood occasioned by alcohol,, 

 which appears to be of signal value in certain morbid con- 

 ditions as chills. In fever the slowing of the pulse, some- 

 times produced by alcohol, is thought to be due to its quieting 

 effect on the central nervous system. 



There is a transient stimulation of the heart induced 

 by the ingestion of strong alcoholic solutions in acting re- 

 flexly on the circulatory centres through irritation of the 

 upper alimentary mucous membrane. 



Large doses of alcohol depress and paralyze the vaso- 

 constrictor centres and heart muscle. 



Digitized by Microsoft® 



