1876.] Action of the Bark of Erytliroplileum guinense. 173 



becomes irregularly contracted, leaving pouches over the surface, and 

 finally is arrested in systole ; the auricles contract for some time longer. 



14. In cats the yentricle also becomes irregularly contracted before 

 finally stopping. 



15. In frogs it causes no rise of the blood-pressure in the aorta, but 

 raises the oscillation of the mercurial column connected with the vessel 

 to three times its pre^dous height. 



16. In cats and dogs moderate doses injected into the jugular vein 

 first raise the blood-pressure without altering the rate of cardiac pulsa- 

 tion or the extent of oscillation at each beat ; they then slow the heart 

 by stimulating the roots of the vagus. The tension rises, notwith- 

 standing the slowness of the heart's beats. An additional dose paralyzes 

 the ends of the vagus in the heart, and quickens its pulsations ; the 

 pressure rises slightly. A further dose again slows the heart by acting 

 on its ganglionic apparatus, and the beats sometimes fall as low as three 

 per minute, three or four respirations occurring during each cardiac 

 diastole. Notwithstanding the very slow action of the heart, the pres- 

 sure may remain as high as 165 millimetres of mercury, a fact which 

 indicates that the arterioles are in a state of extreme contraction. After 

 the heart has ceased, the pressure falls very slowly. Slight pulsations of 

 the ventricle occasionally occur when the thorax is opened. 



17. Small doses do not seem to increase the excitabihty of the peri- 

 pheral ends of the vagi to electrical stimuli ; moderate and large doses 

 paralyze these nerves. 



18. After injection of casca into the veins of an animal completely 

 narcotized by chloroform, electrical irritation of the central end of the 

 divided vagus of one side, the other remaining intact, is followed after a 

 short interval by marked slowing of the pulse, fall of blood-pressure, and 

 increased oscillation. 



19. When injected into the veins of a cat after division of the spinal 

 cord opposite the second cerA^cal vertebra, the blood-pressure rises to a 

 greater height than is attained under other conditions. 



20. "WTien in the rabbit the sympathetic has been divided in the neck 

 on one side, subsequent injection of casca into the jugular vein produces 

 pallor of the recently congested ear of the side on which the division had 

 been made. 



21. When locally applied to the web of a frog's foot temporary slowing 

 of the circulation was observed, but no alteration in the diameter of the 

 blood-vessels. 



"When injected beneath the skin of the back of a frog it produces no 

 visible effect on the vessels of the web. 



22. It does not appear to possess any special action on reflex excitability. 



23. In moderate doses it increases the secretion of urine at the same 

 time that it raises the blood-pressure. Further doses diminish the se- 

 cretion, while they raise the pressure yet more ; and at the time \\"hen 

 the pressure reaches its maximum the secretion of urine is entirely 



