ON THE MOTIONS AND SOUNDS OF THE HEART. 179 
great arteries, and most strikingly over the appendices auri- 
cularum, and thence propagated as it were toward the free 
extremity of the heart, being perceived in the body of the 
ventricles next after the fundus, and at the apex last, as if an 
impulse in a compressed fluid, or a wave commencing about 
the insertions of the arteries, had been propagated along the 
heart from fundus to apex. 
S. 4. After opening the pericardium, small triangular bits 
of white card were applied so as to adhere to the left appen- 
dix, fundus of left ventricle, middle of same cavity, and close 
to the apex; and observation was made, as in last experiment, 
through rolled paper, and with like results (as in S. 3.). 
S.5. And this seeming propagation of motion was per- 
ceived next in another way, viz. by pressing gently on the 
fundus and body of the ventricle and on the apex, by which 
was elicited a sensation, or series of sensations, as of a pro- 
gressive movement of an undulatory character directed from 
fundus to apex, and resembling, to a considerable extent, that 
given by a dropsical abdomen, or hydrocele, &c., when ap- 
propriately percussed. ; 
8.6. During a very vigorous action of the auricles, and at 
a somewhat advanced period of the observation, the shrinking 
and dimpling, in its centre, of the appendix in its systole, was 
likened by several observers to an effect either of suction or 
of some traction exerted on the appendix from some point 
about the auri-ventricular opening, more especially because it 
seemed often separated in time from the ventricular tension, 
roundness and impulse (2. e. systole) bya scarcely perceptible 
interval. 
S. 7. Toward the end of the observation, and during a 
tolerably regular and vigorous action of the heart, the tip of 
the left auricle was snipped off; after which the contractions 
of the appendix became indistinct, those of the ventricle being 
at first little affected. On the instant of cutting off the appen- 
dix, a profuse flow of blood occurred in a stream slightly in- 
creased by a jet during systole of the auricle, and continuous, 
and without any jet, during diastole. 
Note.—The heart ceased to beat after about three quarters 
of an hour of observation, owing to the inflating tube becom- 
ing obstructed by a clot of blood which escaped timely detec- 
tion; it was quite healthy ; the ventricles appeared not to differ 
in size. 
N 2 
