472 ON THE PHYSIOLOGICAL ACTION OF CASCA BARK. 



appearance of dangerous symptoms during tlie administration ol 

 digitalis is due to its stopping excretion by the kidney wliile 

 the drug is still taken by the mouth. The occurrence of 

 poisoning by digitalis would thus be completely analogous to 

 poisoning by cumre in an experiment of Herrmann's.* Curare 

 produces paralysis of motor nerves when quickly introduced 

 into the circulation by injection under the skin or into a vein, 

 but does not usually prove poisonous when taken into the 

 stomach. The reason of this is that it is excreted by the kidneys- 

 as quickly as it is absorbed from the stomach, so that tkere i3 

 never enough of it in the blood at any one time to be injurious. 

 When Herrmann tied the renal vessels, however, so as to prevent 

 excretion, curare taken into the stomach proved as certainly 

 fatal as when injected into a vein. In digitalis-poisoning tlie 

 drug itself causes contraction of the renal vessels, producing the 

 same effect as the ligature applied to them by Herrmann in the 

 case of curare, and the same would probably be the case with 

 casca. 



Action on Hespiration. — The respiration is generally quickened 

 by casca. This quickening appears to be due to a stimulating 

 action of the drug upon the pulmonary branches of the vagus> 

 as it was not observed when the vagi were divided before the 

 casca was administered. 



Action on Temperature. — Casca does not appear to have any 

 action either in lowering or raising the temperature of a healthy 

 animal. We have not yet tried what effect it will have \u 

 fever. 



Action on the Eye, — When applied to the eye it has no action 

 on the pupil, nor does it cause congestion of the conjunctiva or 

 lachrymation. 



Action on the Uterus. — Digitalis having been said to have a 

 powerful action upon the uterus, an action which has been found 

 by Dr. Dickinson to be useful in arresting menorrhagia by 

 causing contraction of the uterus, we administered casca to a 

 pregnant cat, but it did not produce abortion. 



* Du-Bois Heymond's und Heicl.erfs Arch'v, 1S67, p. 64. 



