1030 
frog’s heart were found after poisontng with antiarine. STRAUB ascer-- 
tained moreover that the duration of the refractory stage of the 
ventricle increases after the poisoning with antiarine. Srravs indicates 
this prolongation of. the refractory stage as the cause of the halving 
of the rhythm. 
The prolongation of the refractory stage after poisoning with 
digitalis was ascertained by BRANDENBURG. *) 
The action of the specimens of the digitalisgroup corresponds 
consequently in many regards with that of veratrine. Both with 
digitalis- and veratrine-poisoning we find a decrease of the frequency 
of palpitation, an increase of the size of the systole, a prolongation 
of the refractory stage, which causes the disturbances of rhythm. 
The image of poisoning of the two poisons shows however still — 
important differences. 
Il. My own experiments. 
y } 
A. Method. 
Specimens of Rana Esculenta served as trial-objects. The heart 
was suspended in the usual manner by attaching the point to a 
lever. Care was taken that during the stripping and the preparation 
of the heart the frog lost as little blood as was possible. The 
oscillations of the heart were registered by the lever on an endless 
smoked paper (circumference 2 m.) and enlarged 15 times. Under 
the curves of the heart a line was drawn through the stimulation- 
signal. This indicated the moment at which one of the partitions 
of the, heart was stimulated. A downward movement of the signal 
was brought about by closing the primary circuit of the induction- 
apparatus. The closing induction strokes were blended off. The 
opening of the primary circuit caused an upward movement of 
the signal. The opening induction-strokes were conducted only to the 
preparation. Under the line of the stimulation-apparatus the time 
was registered in seconds. Three series of experiments were made. 
In the first series the irritability of the auricle before and after the 
injection of-digitalis was ascertained. In the second series the same 
experiments were applied to the point of the ventricle, in the 3rd 
series to the basis of the auricle. About 200 systoles were always 
registered before the injection with digitalis. Then 10—15 drops of 
digitalis dialysatum Golaz were injected under the skin of the thigh. 
After the poisoning the curves were registered during several 
hours on the smoked paper. In this way I obtained a survey of 
1) Archiv. f. Physiol. Jahrg. 1904. Suppl. 
