392 SIR THOMAS R. ERASER AND MR ALISTER T. MACKENZIE ON 



12.46. Rate 21 per minute; size of movement 10 mm. (Fig. 4.) 

 12.54. Rate 18 per minute ; size of movement 10 mm. 



1 p.m. Rate 14 per minute; size of movement 11 mm. (Fig. 5.) This additional millimetre is 



in the ventricular movement. 

 1.7. Rate 10 per minute ; size of movement 12 mm. (Fig. 6.) Further increase in ventricular 

 movement. 



1.15. Rate 10 per minute; size of movement 13 mm. Further increase in ventricular move- 

 ment ; occasionally long pauses in diastole occur. 



1.20. Rate 8 per minute ; size of movement 13 mm. (Fig. 7.) With secondary contraction of 

 the ventricle. 



1.25. Rate 4 to 8 per minute; size of movement 13 mm. 



1.28. Long diastolic pauses and another secondary contraction of the ventricle. (Fig. 8.) 



1.32. Diastolic pauses of irregular length. (Fig. 9.) 



1.40. Rate 4 per minute ; size of movement 14 mm. 



1.47. Long diastolic pauses; the auricular movement is a little smaller. 



1.50. Do. (Fig. 10.) 



2 p.m. Rate 11 per minute; size of movement 10 mm. The movement is almost entirely ventri- 



cular ; the auricles are distended and contract superficially only. 

 2.7. Pate 5 per minute ; size of movement 8 mm. As in previous note. 

 2.14. Rate 3 per minute; size of movement 7 mm. 

 2.23. Rate 2 or 3 per minute ; size of movement 7 mm. 

 2.31. Rate 2 or 3 per minute ; size of movement 6 mm. (Fig. 11.) The movement is entirely 



ventricular ; the auricles are greatly dilated ; the ventricle ultimately became arrested 



in diastole. 



In this experiment, the rate of the heart's contractions was much slowed ; the 

 auricular movement, as well as the ventricular, was considerably increased, and long 

 diastolic pauses occurred ; within 2 hours 30 minutes, the auricles were greatly dis- 

 tended and their movement was so feeble as to be unrecorded ; within 3 hours, the 

 ventricle was also distended and paralysed. 



Experiment LXIII. — Heart perfusion (Rana esculenta) : Ringer's solution followed 

 by S. sarmentosus in Ringer's solution (1 in 20,000). (Plate VII.) 



11.37 a.m. Before Strophanthus, the rate of contraction was 26 per minute, and the size of the move- 

 ment was 8 mm. (Fig. 1.) 

 12.5 p.m. Strophanthus perfused. (Fig. 2.) 



12.10. Rate 28 per minute; size of movement 12 mm. This increase is entirely in the ventri- 

 cular movement. 



12.15. Rate 26 per minute; size of movement 13 mm. (Fig. 3.) 



12.25. Rate 14 per minute; size of movement 11 mm. (Fig. 4.) The slowing is due to longer 

 diastolic pauses; the ventricular movement is smaller; the auricular is larger; the 

 ventricle does not relax well. 



12.30. Rate 5 to 6 per minute. (Fig. 5.) This figure shows that the ventricle relaxed less and 

 less after each contraction; at 12.32 the record is entirely auricular and the ventricle is 

 firmly contracted. By 12.45 the auricles were also motionless. 



In this experiment, the rate of the heart was slowed, lengthening of the diastolic 

 pause occurred, and at first the range of ventricular movement was increased. But 

 the ventricle soon ceased to relax properly and then became arrested in systole ; the 

 auricles continued beating after arrest of the ventricle. 



