STROPHANTHUS SARMENTOSUS : ITS PHARMACOLOGICAL ACTION. 391 



5.53. Both the auricles and the ventricle contract imperfectly, hut specially the ventricle. Con- 

 tractions occur in sets of three. (Fig. 11.) Each set begins and ends with an auricular 

 contraction, while the middle contraction is ventricular. 

 6 p.m. Do. 

 6.10. Only the auricles now contract and that imperfectly. All the chambers are engorged 

 and the ventricle shows no sign of movement. The auricular contractions are feeble 

 and superficial. (Fig. 12.) 



In this experiment the rate of the heart was slowed ; the extent of the ventricular 

 movement became gradually lessened until the ventricle was arrested in extreme 

 diastole ; the auricular movement became a little larger ; the auricles continued to 

 contract after the ventricle was arrested, and finally they were arrested in extreme 

 diastole. Diastolic pauses occurred several times in the course of the experiment. 

 Complete paralysis of the heart resulted in 6 hours. 



Experiment LXT. — Heart perfusion (Rana eseulenta) with extract of S. sarmentosus 

 in Ringer's solution (1 in 200,000), after perfusion with Ringer's solution alone. 

 (Plate V.) 



3.38 p.m. Before Strophanthus, the rate of contraction was 27 per minute, and the size of the move- 

 ment was 13 mm. (Fig. 1.) 



3.40. Strophanthus perfused. 



3.45. Rate 31 per minute; size of movement 14 mm. (Fig. 2.) 

 4 p.m. Rate 24 per minute; size of movement 15 mm. (Fig. 3.) 



4.15. Rate 22 per minute ; size of movement 16 mm. (Fig. 4.) 



4.30. Rate 18 per minute; size of movement 15 mm. 



4.40. Rate 14 per minute; size of movement 16 mm. (Fig. 5.) The slowing is seen to be due 

 largely to a lengthening of the diastolic pause ; the movements are also more deliberate 

 than at first. 



4.44. Rate 14 per minute; size of movement 15 mm. 



4.55. Rate 13 per minute; size of movement 14 mm. (Fig. 6.) A small notch due to the 

 auricular contraction is visible. Ventricular relaxation is diminished. 



5.10. Rate 16 per minute; size of movement 9 mm. (Fig. 7.) The diminution in size is due 

 to diminished relaxation of the ventricle in diastole. Finally the heart was arrested with 

 the ventricle firmly contracted. 



In this experiment, there was a brief period of acceleration of the heart's rate soon 

 after Strophanthus ; this was soon followed by slowing of the rate ; the size of the 

 movement was greatly increased, and the diastolic pause was lengthened ; regularity of 

 contraction was maintained ; ultimately the ventricle dilated imperfectly, the rate 

 increased again a little, and the ventricle was finally arrested in systole. 



Experiment LXII. — Heart perfusion [Rana eseulenta) : Ringer's solution followed 

 by S. sarmentosus in Ringer's solution (l in 60,000). (Plate VI.) 



12.4 p.m. Before Strophanthus, the rate of contraction was 37 per minute, and the size of the move- 

 ment was 8 mm. (Fig. 1.) 

 12.12. Strophanthus perfused. (Fig. 2.) 

 12.28. Rate 31 per minute; size of movement 8 mm. (Fig. 3.) Definite increase in the auricular 



movement. 

 12.35. Rate 28 per minute; size of movement 9 mm. 



