ON THE MOTIONS AND SOUNDS OF THE HEART. 185 
other observations, owing probably to delay in the establish- 
ment of artificial breathing) the ventricles entered into their 
systole, and the diastole followed in like order ; first, the venous 
expansion, next the base and appendix of the auricles, and last 
of all the ventricle. 
S.2. In the systole some change of colour was observed 
in the ventricles, from darker to paler, and the same in the 
auricles. 
S. 3. Toward the close of the observations, the auricles 
acted much more frequently than the ventricles, and especially 
the right auricle. In the ventricular systole the apex was 
thought to move slightly outwards and to the left, or away 
from the septum or central axis of the heart. 
Oxsservation VII. 
July 2nd.—Subject, a snake of good size, poisoned with 
prussic acid, so as to be insensible. Heart beating very 
slowly and rather irregularly at first, from 15 to 20 beats per 
minute only. 
Rhythm of motions: After a long pause, first motion ob- 
served in sinus of auricle, and then in appendix, being the 
auricular systole; immediately after which the ventricular 
systole, but with no complete interval between the end of one 
and beginning of the other systole. After the systoles re- 
spectively came the diastoles in like order, and then a long 
pause, equal sometimes to 3 or 4 or more beats. 
At each auricular systole, a swelling observed in the cava 
and pulmonary veins, extending some way down from the 
heart. This appearance resembled a wave of reflux excited 
by the action of the auricle. It was not observed in any part 
beyond a point of the vessels on which pressure was made. 
In the systole, the ventricle shrank concentrically, being 
shorter and narrower, but also rounder and more oval, than in 
diastole ; the ventricle (which might be called bicornute, being 
obtusely pointed at either extremity,) had either horn or ex- 
tremity raised slightly in systole, and depressed again, as if by 
gravitation, in diastole. The cavities systolized and diastolized 
still after the observation was completed, or for more than an 
hour, and more regularly than at first. 
July 2nd.—The ventricle ceased beating after about twenty 
hours, but the auricles were still pulsating regularly after more 
than twenty-four hours. The rhythm of the motions of the 
heart as before, but the reflux wave or diastole of the veins 
now less distinct, owing probably to the emptiness of the 
heart. And in lieu of the regurgitation wave marked by a 
