PHYSIOLOGISCHEN GESELLSCHAFT. — G. FßlTSCH. — A. WALLEK. 187 



associated with. an electrioal Variation. That the latter was a truo physiological 

 Symptom of tho muscular contraction, and not a conseqnence of its mechanical 

 impulse, was proved by photography, which sliewed that the electrical begins 

 bofore the mechanical effect. It then occurred to me that it should be possible 

 to „lead off" the heart by means of the extremities and from any part of the 

 body. The experiment was successful. But not in every case. With certain 

 pairs of parts led off to the two poles of the electrometer, the electrical pul- 

 sations were obvious, with certain other pairs the effects were invisible or 

 hardly visible. For instance — the head and the left hand being connected with 

 the electrometer, the mercury pulsates (wirksame Anordnung); the head and the 

 right hand being similarly connected, the mercury remains motionless (unwirk- 

 same Anordnung). Again — with the right hand and a foot we have a 

 „wirksame Anordnung", whith the left hand and a foot we have a comparatively 

 „unwirksame Anordnung". 



The facts are easily explained. 



Let A und B respectively represeiit apex and base of the ventricular 

 mass. Then if at any moment a difference of potential should arise between 

 A and B a current ccc will be established along and around the axis AB. 

 The line 00 will represent the plane of zero potential or equator. The lines 

 aaa, bbb will represent equipotential curves around A and B. A difference 

 of potential between A and B will be manifested if the two leading off elec- 

 trodes are applied on opposite sides of the equator O O, no such difference 



