444 Dr. J. Wickham Legg on the [Apr. 6 



Remarks. 



Time 

 in seconds. 



In 130 



Pul- 

 sations. 

 31 



He 



in 



ight of curve 

 millimetres. 

 5-5 



55 



32 





6 



55 



38 





4 



55 



31 





6 



?) 





55 



4 



5) 



4 



55 



4 



55 



4 



130 



13 



Curves are double-topped. 



Atropia introduced into serum so that 



it contained '028 per cent. 

 30 6 7 Bile-acids (serum containing 1 per 



cent.) now introduced. 



7 Records in continuous 30 seconds. 



8 The pulse now goes in pairs, 6 S, 5 

 between each pair o£ pulsations. 

 Between the pulses of each pair 3 S, 2. 



8-5 These do not go in pairs. 



9 



8 These go in pairs. 



12 A great change in the character o£ 



curves. Systole reaches maximum 

 height, = 6 millims., in I s - 5. They 

 slowly sink, scarcely meeting abscissa 

 until next contraction begins . Nearly 

 all alike. One takes up 23 millims., 

 others 38 millims. 

 „ 12 - 5 10 Immediately after this the heart ceases 



to beat : no contractions upon elec- 

 trical irritation. 



Four other like experiments with the like results were made : in one 

 of them the bile-acids were added to the serum first, and the atropine 

 added afterwards ; but the same results were attained. The slowness 

 of the pulse arose as before, and was unchanged by the addition of the 

 atropine. If it be true, then, that atropine paralyzes the ends of the 

 vagus in the heart, it would appear that the slow pulse is not due to any 

 excitement of the ends of these nerves in the heart. The great height of 

 the curves just before the heart ceased to beat does not favour, either, the 

 belief that the slow pulse is due to a weakening of the muscular walls. 



In order to test the foregoing experiments, I made further experiments 

 upon the irritability of the vagus in poisoning by the bile-acids. 



The heart and vagus of a frog laid bare. Heart beating 12 in 15 s . 

 The right vagus then irritated by induced electricity : the heart stood still 

 in diastole. Three or four drops of the pharmaceutical solution of 

 atropine now let fall npon the heart. Five minutes after the beats were 

 7 in 15 s . The right vagus was then again irritated by induced electricity, 

 with no change in the heart. After ten minutes, four drops of a 10-per- 

 cent, solution of bile-acids were let fall npon the heart and neighbour- 

 hood. Thereupon, for nearly a minute, the heart-beats rose to 10 in 15 s , 



