DR THOMAS R. FRASER ON STROPHANTHUS HISPIDUS. 457 



Experiment Plate XVII. 



CXIV. Frog-heart tracings. 1, after atropine; 2 to 8, after atropine and strophanthin. The effects are 

 much the same as in the previous experiment, but more decided increase of ventricular diastole is 

 indicated. 



Plate XVIII. 



CXXI. Frog-heart tracings. 1, before strophanthin ; 2, after strophanthin ; 3 and 4, after both strophan- 

 thin and atropine. Tracings 3 and 4 show the production by strophanthin of greatly exaggerated 

 ventricular systole, with consequent reduction of diastole, notwithstanding the application of 

 atropine. 



CXXII. Frog-heart tracings. 1, 2, and 3, after application to the heart of both strophanthin and atropine. 

 The tracings show slowing caused by increase of ventricular diastole, although the vagus was 

 paralysed by atropine. 



Plate XIX. 



Curves of Experiments CXXV., CXXVL, CXXXL, CXXXIV., CXXXV., and CXLV., representing the effects 

 produced on the blood-vessels of frogs by perfusion of solutions of extract of Strophanthus and 

 of digitalin. 



Plate XX. 



Curves of Experiments CXXIV., CXXXVL, CXXXVIL, CXL., CXLI, CXLIL, CXLIII., and CXLIV., 

 representing the effects produced on the blood-vessels of frogs by perfusion of solutions of stro- 

 phanthin and digitalin. 



Plate XXI. 



CXLVI. Blood-pressure tracings from carotid artery of a rabbit. 1, before strophanthin; 2 to 12, after 

 - 06 grains of strophanthin had been injected under the skin. The tracings show great 

 increase of pulse movements, with blood-pressure below, above, and equal to its initial state. 

 CXLVIII. Blood-pressure tracings from carotid artery of a rabbit. 1, before strophanthin; 2 to 6, after injec- 

 tion of strophanthin into a jugular vein (total dose, O01 grain). The average blood-pressure was 

 little affected until towards the end of the experiment, and after the last of the divided doses 

 of strophanthin had been injected; but the pulse movements were markedly increased during a 

 considerable part of the experiment, and both when the average blood-pressure was little removed 

 from its normal elevation and when it was high. 



Plate XXII. 



CXLVII. Blood-pressure tracings from carotid artery of a rabbit. 1, before strophanthin; 2 to 13, after 

 injection of strophanthin into a jugular vein (0-012 grain). These tracings also show much 

 increase of pulse movements in varying states of blood-pressure. 



Plate XXIII. 



CL. Blood-pressure tracings from carotid artery of a rabbit. Atropine was injected at various intervals 

 after repeated doses of strophanthin, and the vagus nerve was stimulated from time to time. 1 

 and 2, before injection of atropine ; 3 to 12, after injection of atropine and strophanthin. In 2, 

 the cardio-inhibitory action of the vagus is shown to be active before the injection of atropine. 

 In 4, 8, 10, and 11, it is shown to be paralysed after injections of atropine; and yet strophanthin 

 succeeded in producing changes in the blood-pressure and on the pulse movements similar to 

 those recorded in the experiments in which no atropine had been administered (Plates XXI. and 

 XXII.). 



