Emetics are divided commonly into two classes: (a) Those which irritate certain nerve endings in the gastric mucous membrane; (b) those which stimulate the vomiting center in the medulla directly.
Hatcher and Eggleston1 showed that emesis follows the intravenous injection of any one of the several digitalis bodies in dogs, even after the removal of the gastro-intestinal tract, and while they considered it possible that vomiting is due to a reflex arising in some peripheral structure, such as the esophagus, they came to the conclusion that all the evidence available points to the vomiting center as the seat of the emetic action of all of the digitalis bodies.
The fact that these bodies differ so widely in their chemical composition directed our attention to the coincidence that every member of the group shows a greater or less parallelism between its cardiac and emetic activities, though the several members of the
HATCHER RA, WEISS S. THE SEAT OF THE EMETIC ACTION OF THE DIGITALIS BODIES. Arch Intern Med (Chic). 1922;29(5):690-704. doi:10.1001/archinte.1922.00110050140009