186 REPORT— 1840. 
diastole, followed by a systole, and then a pause in the veins, 
there was observed an opposite order of the motions, viz. 
1. venous systole; 2. venous diastole; 3. then the pause. 
Several times the motions of the veins were observed alone, 
and not preceded by auricular contraction, or accompanied by 
it, as, toward the close in other observations, auricular con- 
traction had often failed to excite or be followed by ventricu- 
lar systole. 
OssErRvaTION VIII. 
July 4th.—Subject, a Donkey nine months old, in good 
health. Pulse beating well in precordia about 70 or 80. Opera- 
tion of injection tedious, with considerable hemorrhage ; whole 
operation lasted kalf an hour, and heart acted for considera- 
bly more than an hour. When opened, the heart was beating 
quickly (above 100) but regularly. Second sound indistinct. 
Phenomena: Effects of pressure on the heart ;—action of 
threaded auricles ;—no sound, and why ;—manner of auricular 
diastole ;—resistance to pencil in mitral orifices, and how 
caused ;—pulsation of cava;—phenomena of ventricular sy- 
stole ;—mechanism of cardiac impulse ;—valvular jerk over the 
mitral opening in systole, and modifications of first sound arti- 
ficially produced ;—hemorrhage from left auricle ;—relative 
sizes of ventricles. 
S. 1. The stethoscope, loaded with 4 to 5 lbs. of shot, &c., 
and placed on the ventricles as before, was jerked up by each 
systole, and subsided and deeply indented the parietes in 
each diastole. 
S. 2. The callipers were applied as before, but with a ten- 
sion much exceeding that formerly used, and with a similar 
but not equal result ; the heart being considerably less vigor- 
ous, as well as the spring much stiffer. The action became 
much hurried under the pressure of the instrument, but its 
legs were pushed asunder with force in systole, and a deep 
indentation was caused by them in the parietes in diastole, 
which did not wholly disappear sometimes in systole. 
S.3. The tip of the appendix of the left auricle was 
threaded as before, and the auricle and ventricle acted nearly 
but not exactly in alternation, and the thread was felt to be 
forcibly drawn downwards at the moment of auricular dimp- 
ling and systole. 
S. 4. No auricular sound could be distinguished, apparently 
less attributable towant of energy in the auricle than to the rapid 
beat of the heart and sudden supervention of the ventricular sy- 
stole before the completion of the auricular. The left appendix 
