41G DR THOMAS R. FRASER ON STROPHANTHUS HISPIDUS. 



7.16. Do. Occasional throat respirations, and fairly strong general struggles. 

 On Vie following day, at 



10.30 to 10.40 a.m. Heart's contractions from 1 to 1| per 30 sec. Pauses in extreme diastole of the ventricle. 

 10.43. Applied to surface of heart 0-003 grain of sulphate of atropine in solution. 



10.47 to 1.55. Heart's contractions from 1 to 2 per 30 sec. Pauses in extreme diastole of ventricle. No 

 respiratory movements. Active reflex contractions. 



It is shown by this experiment that after the diastolic type of cardiac action had been 

 in existence for several hours, atropine was unable to prevent its continuance for at least 

 3 hours longer. 



In the next two experiments of this series, the changes in the heart are illustrated by 

 cardiographic tracings exhibiting the systolic and the diastolic type, respectively, of 

 Strophanthus action. 



Experiment CXX1. — Weight of frog {Rana esculenta), 1320 grains. 0*002 grain of 

 strophanthin applied to heart in divided doses, and afterwards 0*003 grain of sulphate of 

 atropine. (Plate XVIII.) 



11.15. Frog pithed. 



1.25. Cardiograph applied. 

 1.30. Tracing No. 1. 



1.34. Applied to heart \ minim of - 05 per cent, solution of strophanthin ( = 0-00025 grain). 

 1.49. Second application of strophanthin solution, 1 minim ( = 0-0005 grain). 



2.15. Third application of strophanthin solution, \\ minims ( = 0'00075 grain). 

 2-55. Cardiograph curve has fallen below abscissa-line ; raised frog and cardiograph. 



3.1. Fourth application of strophanthin solution, 1 minim ( = 0-0005 grain). 



3.18. Tracing No. 2. Slowing and considerable increase of auricular contraction. Ventricular pauses 



are in diastole. 

 3.20. Applied to heart - 003 grain of sulphate of atropine in solution. 

 3.30. Cardiograph tracing has risen further from abscissa, requiring a readjustment. 



3.35. Ventricle is smaller and paler, and it dilates much less during diastole. 



3.48. Tracing No. 3. Curve is chiefly produced by auricular contraction, only the slight elevation in the 



descending portion being produced by the ventricle systole. 

 4.20. Tracing No. 4. Extremely faint, doubtful contractions of ventricle, which is small and pale. 



Removed the cardiograph : ventricle very pale and small ; auricles large and dark. 



Experiment CXXII. — Weight of frog [Rana esculenta), 780 grains. 0*0015 grain 

 of strophanthin applied to heart in four doses, and afterwards 0*003 grain of sulphate of 

 atropine. On the following day, the vagus tested, and tracings taken of the heart's con- 

 tractions, after a fifth application of strophanthin. (Plate XVIII.) 

 10.50. Frog pithed. 

 2.30. Heart exposed. 

 2.38. Heart's contractions 16 per 30 sec. 



2.48. Applied to heart 1 minim of 0-05 per cent, solution of strophanthin ( = 0-0005 grain). 

 3.0. Heart's contractions 14 per 30 sec. 



3.15. Heart's contractions 12 per 30 sec. Ventricular systole complete, diastole prolonged. 

 4.0. Heart's contractions 11 per 30 sec. Do. 



4.2. Second application of strophanthin solution, \ minim ( = 0-00025 grain). 



4.26. Heart's contractions 10 per 30 sec. Distinct pauses of ventricle in extreme diastole. 

 4.46. Do. do. 



4.57. Third application of strophanthin solution, £ minim ( = - 00025 grain). 



5.16. Heart's contractions 8 per 30 sec. Ventricle occasionally pauses in extreme diastole. 



