XXII. Note on independent pulsation of the pulmonary veins and vena cava

Abstract In a former communication we incidentally mentioned that in a rabbit killed by the injection of cobra-poison into the jugular vein we had observed the pulmonary vein pulsating after all motion had ceased in the cavities of the heart. We have since observed the same phenomenon three or four times under conditions which show that this pulsation is not due to the action of the cobra-poison with which the animal in which we first observed it had been killed. The following example will show the changes in rhythm observed in these pulsations. A cat was chloroformed, and the vagi exposed and irritated by an interrupted current. Artificial respiration was kept up by air containing chloroform vapour, and the thorax was then opened, and a solution of atropia injected directly into the heart by means of a Wood’s syringe. The vagi were again irritated, but without any effect being produced on the heart, the inhibitory apparatus in it being evidently paralyzed by the atropia. A solution of glycerine extract of physostigma was now injected into the heart in a similar way. The vagi were now irritated again, and the heart stood still, the effect of the atropia having been counteracted by the physostigma. After the irritation ceased the heart again commenced to pulsate.