200 REPORT—1840. 
heart, again descended also steadily and during several beats. 
After a few moments, the tube being held upright with care, 
and the lower opening of the tube being toward the abdomen, 
and pressure being made on the tube through the parietes of 
the veins, a column of blood ascended slowly and steadily to 
the top of the tube and poured over at the top. Again, press- 
ure being withdrawn from the cava, fluctuation occurred, viz. 
irregular ascents and descents of the column, gradual and slow, 
and extending each of them over several beats of the heart, 
there being perhaps as many as half a dozen of each to each 
minute of the time they lasted. At no time was there any sud- 
den elevation or subsidence of the column, such as the auricular 
systole or ventricular diastole might be supposed to produce, 
supposing the latter to include suction towards the ventricles. 
The variations of level observed in the tube could be referred 
with any probability to nothing obvious, except the convulsive 
agitation of the right thorax, which was intact, and which 
heaved and collapsed violently for a short time, owing to a 
partial recovery of the animal from the stunning blow during 
the operation, in consequence of hemorrhage and artificially 
sustained breathing. ‘The tube was then introduced into the 
cava superior, and a column was observed in the whole length 
of the narrow part of the tube, and nearly an inch in height, 
and this column suffered no alteration either in systole or dia- 
stole. The shortness of the column in this case was owing ob- 
viously to exhaustion of the vascular system, or insufficiency 
of blood and of vascular tension. ‘There was not any respira- 
tory effort during this last observation. 
S. 2. During this last observation (on the cava superior) the 
unusual appearance was observed of complete quiescence nearly 
of the auricles, whilst the ventricles continued to act with con- 
siderable energy. The early death of the right auricle might 
be referred to withdrawal of supplies from the cava inferior 
especially; but that of the left auricle is not easily accounted 
for, since insufflation was duly persevered in. 
S. 3. The heart was cut out while yet contractile, and the 
columnz carnez of the right ventricle were observed to act 
accurately with the parietes, whether the stimulus were applied 
to the former or latter only. The columne of the left ventricle 
were become insensible to stimuli, and the parietes nearly so 
before the left was laid open for observation. 
S. 4. The elevation of the central cardiac axis, and espe- 
cially of its free extremity, viz. the apex cordis, was very con- 
spicuous in systole, and the opposite motions in diastole. Also 
the flattening and lengthening of the ventricles in diastole, and 
