778 DR FRASER ON THE PHYSIOLOGICAL ACTION 



A drop of filtered concentrated solution of the extract was placed on the pericardium. 

 In 1 minute, heart = 52 per minute. 

 2 „ = 40 



4 „ -36 



6 „ = 30 



8 ,, =24 „ 



10 „ irregular; eighteen ventricular and twenty auricular contractions. 



13 „ „ no ventricular and eleven auricular contractions. 



14 

 22 „ =8 per minute ; both chambers contract, but the ventricles very 



feebly. 

 25—12 



40 „ =15 „ very feeble, but rhythmical. 



50 „ irregular; twelve ventricular and fifteen auricular contractions. 



52 „ „ no ventricular and eighteen auricular contractions. 



The ventricles did not again contract spontaneously, but the auricular action continued for 

 many hours. Voluntary movements were made by the frog until fifty minutes after the poison 

 had been placed on its pericardium.* 



b. To the Heart. 

 Experiment XCVIII. 



A portion of the pericardium was removed from the exposed heart of a frog ; and, during 

 ten minutes that followed this operation, its contractions varied little from forty-five in the 

 minute. A small drop of the same solution of extract as was employed in the previous experi- 

 ment was placed on the heart's surface. 



In ten seconds, heart = 0. 



It continued motionless for thirty seconds ; then recommenced ; but, almost immediately 

 afterwards, the frog struggled violently, and the contractions again ceased for ten seconds. 



In 2 minutes, heart = 27 per minute. 

 4 „ =21 



6 „ =30 



8 „ =34 „ Rhythmical and regular. 



At this time, a second drop was applied to the heart. 



In 30 seconds, a struggle occurred, and the heart stopped for ten seconds. When it recom- 

 menced, the contractions were irregular, only five ventricular to ten auri- 

 cular occurring in the minute. 

 In 3 minutes, there were no ventricular movements and 6 auricular. 

 10 „ „ 20 



12 ,, heart = 23 per minute ; rhythmical but irregular. 

 20 „ „ = 28 „ „ and regular. 



4u » » = 28 ,, „ „ 



A third drop was now applied. 



T o • i a. n i.i • i t -• i j.- t f no ventricular movement, 



In 2 mmutes alter the third application, heart irregular, \ , 9 , . , 



8 » » 



h f both ventricles and auri- 



lo » „ = 7 per minute, < , ... 



1 t cles contracting. 



25 „ „ =0 „ 



In this and in the other experiments of the series, a drop of water was occasionally placed on 

 the heart to prevent its surface from drying. 



