IPECACUANHA. 77 



CLASS VIII. — EMETICS. 



"Medicines which, as an ordinary result, produce vomiting." 

 The effect of an emetic is not immediate; usually from 10 to 20 

 minutes elapse before vomiting occurs. Emesis is partly the act of 

 the stomach, and partly of the brain and spinal marrow : if the 

 brain be stupefied by narcotics, the stomach becomes very insus- 

 ceptible to the action of emetics. Some emetics act only if imrae- 

 diately applied to the stomach ; others produce their effect no matter 

 how introduced into the system. The act of vomiting is chiefly 

 reflex. If the eighth pair of nerves be cut, no vomiting is produced 

 by emetics. The susceptibility to their influence is increased by 

 irritation or inflammation of the stomach, and by fever; it is les- 

 sened by nervous disorders, and by narcotic poisons. 



Emetics are useful to remove improper matters from the stomach, 

 as poisons or ingesta ; to deplete from the system ; to promote the 

 secretions ; to produce muscular relaxation ; to give a shock to the 

 system, and thus break up morbid associations ; to cause pressure on 

 the surrounding viscera; to reduce arterial action ; and to cause re- 

 vulsion to the stomach. They should be avoided, if possible, in 

 congestion of the brain, hernia, the advanced stages of pregnancy, 

 and in inflammation of the stomach and surrounding parts. 



Ipecacuanha, U. S. 



Root of the Cephaelis ipecacuanha, a perennial plant, growing in 

 Brazil ; about 5 or 6 inches high. The roots, as met with in the 



Fig. 15. 



