51.4 ON THE PHYSIOLOGICAL ACTION OF CASCA BARK. 



strong, the pulsation in an artery being felt very powerfully 

 when the finger is laid upon it, and the rise of pressure during 

 it being very great, as shown by the oscillation of the mercurial 

 column of the manometer. 



In order to ascertain more exactly whether the inhibitory 

 cardiac ganglia were stimulated or not the following experiment 

 was tried : — 



Experiment XXXIX. 



A dog was chloroformed, and 7 c.c. of a concentrated watery 

 solution of casca were injected into the jugular vein. 



The pulse at the time of injection was 37 in ten seconds. 

 In ten seconds after the injection it sank to 20. After the 

 injection of 3 c.c. more the pulse rose to 37. After a further 

 injection of 26 c.c. more in divided doses it again sank to 16. 



This number was, however, uncertain, as the tracing was a 

 very imperfect one. 



The injection of 1 c.c. of liquor atropise, B.P., did not seem 

 to alter the number of the pulse, but the injection of | a c.c. 

 more seemed to cause it again to become quick. 



This seems to indicate that the slowing is due to an action of 

 the casca on the inhibitory ganglia. The imperfection of the 

 tracing renders the result somewhat uncertain ; but want of 

 time prohibited us from repeating the experiment, although we 

 greatly desired to do so. 



Experiments XL, XLI. — March 15. 



The effects on the capillaries of the frog's web were micro- 

 scopically observed in Experiment XL after an injection of 

 casca under the skin of the back, in Experiment XLI when 

 locally applied to the web. 



The capillaries were observed with oc. 2 obj. 4 of Hartnack. 

 In the first case, i.e., after the drug had been injected, the 

 results were purely negative. In the second, after application 

 of a drop of strong casca solution to the web, the results were 

 also indecisive. In the capillaries, and also in the larger trunks, 

 the current was at first slowed, and in some permanent stasis 

 occurred. When slowing only was produced, the partial arrest 



