STROPHANTHUS SARMENTOSUS : ITS PHARMACOLOGICAL ACTION. 



385 



vagus arrested the heart in diastole, but a second application of the same dose of atro- 

 pine abolished the vagus-action for other two hours. When 0*00005 gram of sulphate 

 of atropine was applied to the heart in the same way, the vagus, which had previously 

 been ascertained to be active, failed to slow or arrest the heart, when electrically stimu- 

 lated, during four hours ; but after the lapse of four hours electrical stimulation of the 

 nerve was followed by arrest of the heart in diastole for several seconds. Larger 

 amounts of sulphate of atropine appeared to affect the cardiac muscle. 



Atropine after Strophanthus. 



Experiment LVI. — 0*0004 gram of extract instilled within the pericardial sac of a 

 frog (Rana temporaria) and, when the effects developed, 0*000025 gram of sulphate 

 of atropine instilled. 







Contractions 



in 10 seconds. 







Interval. 







Notes. 











Auricles. 



Ventricle. 





Before Strophanthus. 









3 minutes . 



5 



5 



Contractions regular in time and powerful ; ventricular 











systole occupies two-thirds of the cycle. 











Inserted 0004 gram of extract of Strophanthus dissolved 











in Ringer's solution inside the pericardial sac. 



Aftet 



Strophanthus. 









4 minutes . 



6 



6 



All chambers are larger in diastole and all contract well in 











systole. 



8 



)> 



7 



7 



Do. do. ' 



10 



>) 



7 



7 



Contractions regular and powerful ; ventricular systole occupies 

 two-thirds of the cycle ; auricles and ventricle are very 

 large in diastole and contract very well in systole. 



15 



» • • 



6 



6 



Do. do. 



20 



>> • • 



6 



6 



The auricles are greatly dilated in diastole and expel only 

 half their contents in systole ; the ventricle is small and 

 pale, and only the apex dilates at each auricular systole. 



23 



)> 



6 



6 



The auricles fail to expel their contents and the ventricle is 

 almost in complete systole. 



25 



>» 







0000025 gram of atropine sulphate in solution inserted 

 inside pericardium. 



26 



>> 



6 



6 



As last noted. 



30 



)> • 



... 





Six auricular and six ventricular contractions in 30 seconds ; 

 the auricles fail to expel even half of their contents ; 

 ventricular expansion in diastole very slight. 



35 



>) • 







The heart is arrested with the ventricle small and pale and the 

 auricles large and dark ; occasional contractions of the auricles 

 occur, followed by a feeble movement of the ventricle. 



40 



jj • 



4 



4 



Characters as at 33 minutes. 



45 



M 



4 



4 



Do. 



55 



5) 



4 



4 



Do. 



70 



)) • 







Pause for 15 seconds with the auricles moderately dilated 

 and the ventricle a little relaxed ; thereafter the auricles 

 expelled their contents better into the ventricle, which was 

 less contracted. 



