ON THE MOTIONS AND SOUNDS OF THE HEART. 187 
was repeatedly inverted with a pencil and with the finger, and on 
the instant of being let free, by withdrawal of the pencil, &c., 
recovered its shape and position, appearing to emerge with 
rapidity out of the auri-ventricular orifice and sinus, appa- 
rently owing to a continuous and copious influx of venous 
blood into the appendix, especially during the systole of the 
ventricles. 
S. 5. In experiments on the mitral valves, repetitions of 
former trials, and with inverted auricles, some resistance, as 
of a hard edge, was repeatedly felt by the finger, and the 
pencil was pushed outwards with some force, but the edge felt 
was suspected to be the edge of the interior orifice and not 
that of a valve. On the inner side, or that next the septum, 
the resistance in systole was more energetic than on the 
outer. 
S.6. The thread that had been passed through the ap- 
pendix was drawn upwards, to check the systole of the auricle 
during auscultation, but the operation was with difficulty per- 
formed, and at all events no perceptible difference resulted ; 
the first cardiac sound appeared unchanged. 
S. 7. A slight motion of the cava was observed accompany- 
ing the auricular systole, viz. a diastole followed by a systole ; 
both slight. 
S. 8. In systole the ventricle became rounder, harder, 
tenser, and shorter; both fundus and apex, but especially the 
latter, were seen to be elevated, and the apex seemed to turn 
slightly from left to right. 
S.9. An eccentric impulse, or abrupt push outwards, was 
perceived on whatever part of the ventricle we touched, while 
the heart acted with any energy; and this push or impulse 
was most striking, though least powerful, just at the apex, on 
account, as it seemed, of its pointed form. 
S. 10. An undulatory sort of motion was perceived in 
systole from fundus to apex, along the parietes. In addition 
to the general eccentric impulse, there was observed over the 
orifices, arterial and auricular, a jerking motion not observed 
elsewhere; and this jerking was indistinct or null over the in- 
terior orifice, in a subsequent experiment, in which the mitral 
valves were prevented from closing by a slender instrument 
something like scissors, the parts of which beyond the joint 
were introduced, through the auricle, without inverting it, into 
the auri-ventricular opening; and while the blades were kept 
separate, the first sound, as heard on the ventricles, was 
found to begin dull and obtuse; and an obtuse beginning, and 
a well-defined beginning were heard alternately, according as 
