ALCOHOL. 215 



stimulant, but always a narcotic. The effect on the capil- 

 laries is explained as follows : In ordinary conditions of 

 circulation, when only a moderate amount of blood is 

 needed in any given organ, the circular muscle fibers in the 

 walls of the arteries leading to that part are kept shortened 

 by nervous impulses sent to them from the nerve centers 

 which control them, hence a moderate supply of blood. A 

 narcotic has a paralyzing effect on these nerve centers ; 

 hence the usual impulses which would have been sent are 

 no longer sent, the muscle fibers relax, the artery widens, 

 and the part becomes flushed. 



In regard to the effect on the action of the heart, it must 

 be remembered that in the first place there are ganglia 

 imbedded in the walls of the heart, and that the heart 

 tends to beat rhythmically ; second, that there are two sets 

 of nerve fibers reaching the heart from without, the sym- 

 pathetic, which bring impulses which quicken the activity 

 of the heart, and the vagus nerves, which slow its action. 

 The sympathetic fibers are accelerators, while the vagus 

 fibers retard ; the vagus nerves exert an inhibitory effect, 

 i.e. they act as a brake on the heart's action. If they were 

 strongly stimulated, the heart would stop. If impulses are 

 not continually sent to the heart along these fibers, the 

 heart begins to beat faster, just as a wagon going down 

 hill begins to go faster when the brake is taken off. 



The action of the narcotic is to paralyze the nerve center 

 from which the restraining impulses normally are sent to 

 control the heart. Hence the rapid beat. As to the force 

 of its beat there is difference of opinion ; many maintain 

 that it has less force than before. 



Under the influence of alcohol the person says and does 

 foolish things; he violates confidence; he proposes, and 

 engages in, rash undertakings ; his higher nerve centers in 



