380 



SIR THOMAS R. FRASER AND MR ALISTER T. MACKENZIE ON 



Experiment LIU. — continued. 



Interval. 



Contractions in 10 seconds. 



Notes. 



Auricles. 



Ventricle. 



After Strophanthus. 

 283 minutes . 



5 hours 



22 hours 30 mins. . 



51 „ 40 „ . 



52 „ 53 „ . 



4 



4 

 6 



4 



4 

 6 



The heart paused in diastole for 5 seconds ; such pauses 

 occur spontaneously, and may also be induced by letting the 

 edge of the funnel fall sharply on the thighs of the frog. 



Regular and powerful contractions ; ventricular systole and 

 diastole each occupy half the cycle ; ventricular diastole 

 shows one phase before and one phase accompanying 

 auricular systole; in systole, the ventricle is well con- 

 tracted and moderately pale. 



Contractions regular, but less powerful; other notes as last 

 recorded; in diastole, the ventricle is smaller than before, 

 and mottled. 



Regular and feeble contractions ; auricles and ventricle are 

 very pale and small ; general reflexes elicitable. 



The heart is motionless ; the auricles are small and pale ; 

 the ventricle is small and purplish in colour ; mechanical 

 stimulation of the ventricle results in several feeble move- 

 ments of all chambers of the heart ; general reflexes can 

 be elicited ; respiratory movements have ceased ; on section, 

 the ventricle was empty and its cavity small ; the reaction 

 of its muscle to litmus was doubtful — perhaps faintly acid. 



Experiment LIV. — 0*00005 gram of extract placed within the pericardial sac of 

 a frog (Rana temporaria). 



Interval. 



Before StrophanDius. 

 10 minutes . 



1 minute 



After Strojihauthus 



2 minutes 



5 „ 



8 „ 

 10 „ 

 20 „ 



Contractions in 10 seconds. 



Auricles. Ventricle. 



Notes. 



Contractions powerful and regular in time ; ventricular 

 systole occupies two-thirds of the cycle ; the diastolic move- 

 ment of the ventricle is abrupt, the systolic is deliberate. 



As last noted. 



0-00005 gram of extract in Ringer's solution inserted inside 

 the pericardial sac. 



As last noted. 



Do., but ventricle is perhaps paler in systole. 



Contractions regular and powerful ; ventricular diastole now 

 occupies one-half of the cycle; in systole the ventricle 

 becomes very pale ; the diastolic movement of the ventricle 

 is prolonged, and is in two phases, one before and the 

 other accompanying auricular systole. 



