Emetic Action of Tartar Emetic. 



387 



that either the normal pacemaker or some ectopic source is enabled 

 to reassert its rhythmic function and thus interrupt the circus 

 movement. 



In conclusion it should be remembered that the hypothesis 

 here given is different from, but not contradictory to the hypothe- 

 sis of Lewis. Both hypotheses are valid. In fact it is probable 

 that both mechanisms take place and so explain the two different 

 ways in which atrial fibrillation returns to normal rhythm. We 

 refer to the sequence with quinidin — i.e., fibrillation, flutter, nor- 

 mal rhythm, and the sequence under digitalis of flutter, brief fi- 

 brillation, and normal rhythm. 



188 (1935) 



The emetic action of antimony and potassium tartrate (tartar 



emetic). 



By SOMA WEISS and ROBERT A. HATCHER. 



[From the Department of Pharmacology, Cornell Medical College, 



New York City.} 



Tartar emetic (antimony and potassium tartrate) induces 

 vomiting reflexly through local irritation after its introduction 

 into the stomach or duodenum. The portion of the duodenum 

 lying immediately below the pylorus is more sensitive than the 

 stomach. Concentrated solutions are more active than dilute 

 solutions in inducing this reflex. 



Tartar emetic does not cause emesis in the cat or dog, when it 

 is applied directly to the vomiting center decribed by Thumas, and 

 which lies in the floor of the fourth ventricle. 



Intravenous injections of tartar emetic induce vomiting after 

 varying intervals of time, largely dependent on the size of the dose. 

 This emesis is not prevented by the removal of the gastrointes- 

 tinal tract, or by the removal of the celiac plexus and simultane- 

 ous cutting of the vagi below the diaphragm, but it is profoundly 

 influenced by cutting the vagi in the neck, or paralyzing the 

 vagus endings with atropin; it is apparently abolished by sever- 

 ing all nervous connection between the heart and centers by 



