OF THE BARK OF ERYTHROPHLEUM GUINENSE. 
641 
When the heart of a frog is exposed, but not removed from the body, and a solution 
of casca is injected beneath the skin, the heart’s action is slowed, and is eventually 
stopped in systole ; previous to its stopping, however, pouch-like dilatations are formed ; 
in this respect the action of casca is similar to that of digitalis and other cardiac poisons. 
Experiment XXXI. — April 27. 
A cat was chloroformed ; a cannula placed in the left jugular vein and one in the 
trachea. Artificial respiration was commenced, and the thorax was opened The heart 
was beating regularly, but it was difficult to count the pulsations. They were counted 
by one person as 90, by another as 180. 
10 cub. centims. of a saturated watery solution of watery extract of casca were 
injected into the jugular vein. No apparent effect was produced. 
7 cub. centims. more were injected in the course of a few minutes. Within about a 
minute of the last injection the ventricle no longer contracted as a whole, but became 
pouched, the upper half seeming to overlap the under half so as to produce a trans- 
verse fold. 
A few seconds afterwards, the lungs, which had hitherto been rosy, became white, and 
almost immediately the motions of all cavities of the heart completely ceased. On 
irritation of the ventricle no movement occurred. 
Both vagi were divided, but without effect on the heart. 
It was noticed that the rosy colour of the lungs returned, although the heart did not 
again beat. No pulsations were noticed in the pulmonary vessels. The heart was 
perfectly firm, and seemed to be in systole ; but on tying a ligature round the base so as 
to include the large vessels, it contracted to about one third of its former size. 
The action of casca on the mammalian heart is seen from this experiment to be 
similar to its action on the heart of the frog. 
Experiment XXXII. 
Action on Blood-Pressure in the Frog. 
The cerebrum of a large frog was destroyed. A cannula was then inserted into the 
left aorta, and was connected with a small kymograph, the pulse-wave and oscillation 
being recorded on a revolving drum. 
The appended curves give the oscillations of pressure in the aorta, and show that 
under the influence of casca the blood-pressure in the aorta rises to twice its normal 
height during systole, although it falls to zero during diastole. 
Normal pulse (10 millims.) 
Pulse three minutes after injection of 1 cub. centim. of 1 
a To D" solution of casca into flank J 
Pulse one minute after a second injection of 1 cub. centim. 
Pulse three minutes later 
