1891.] Electromotive Phenomena of the Mammalian Heart. 211 



nected with the taking of food, is hardly to be expected to be among 

 the results of stimulation of starving cells. 



In studying the effects of drugs it will be useful to consider the 

 relation of these various effects in order to understand the special 

 mode of action of the agent employed. 



By these observations we have also obtained indications of the 

 ways in which cells can be placed in different states of activity, so 

 that, by the administration of drugs at various times after a meal, we 

 can study more accurately what accelerating, restraining, or other- 

 wise modifying, influences the drug may have. 



We have been driven to consider, incidentally, some other problems, 

 such as the relations which exist between contractility and secretory 

 activity, but such things cannot be considered fully in this com- 

 munication. 



V. " On the Electromotive Phenomena of the Mammalian 

 Heart." By W. M. BAYLISS, B.A., B.Sc., and ERNEST H. 

 STARLING, M.D., M.R.C.P., Joint Lecturer on Physiology at 

 Guy's Hospital. (From the Physiological Laboratory, 

 University College, London.) Communicated by E. A. 

 SCHAFER, F.R.S. Received October 23, 1891. 



(Abstract.) 



Methods of Research. The heart being exposed, two points of its 

 surface were connected by means of non-polarisable electrodes with 

 the terminals of a capillary electrometer. An image of the meniscus 

 was thrown on to a moving photographic plate, on which were also 

 recorded the contractions of the ventricle, a time tracing (8 or 100 

 per second), and in many cases the time of stimulation (when 

 artificial stimuli were used), or the period of excitation of the vagus 

 (when it was desired to slow the heart). In nearly all experiments 

 we used dogs. 



We have also made experiments on the excised heart. In these, 

 the heart, immediately after the chest was opened, was placed in a 

 warm moist chamber. The wires of the electrodes and the tube 

 going to the tambour recording the heart beats passed through holes 

 in the sides of the chamber. 



Results. As to the wave of negativity in the ventricle, we find 

 that in animals whose hearts are in as normal a condition as possible 

 the variation is always diphasic, the negativity at the base preceding 

 that at the apex. The result is the same whether the pericardium be 

 intact or opened, or whatever points of the ventricular surface are 

 led off. 



