248 
FIFTH REPORT — 1835 . 
bling the‘first’ sound was heard. Also when the grasp of the 
hand was suddenly relaxed, a sound was heard of the same cha¬ 
racter as the one preceding. The ear-tube having been applied 
to the ventricles in the dead and empty heart, and their internal 
surfaces being rubbed against each other, a sound was heard 
much resembling the ‘first’ sound : and the finger having been 
introduced into the left ventricle, and being gently rubbed 
against the internal surface, a sound, also resembling the ‘first’ 
sound, was produced. 
A glass tube allowed to drop from a small height on the se¬ 
milunar valves of the aorta, caused a sound having the character 
of the second sound; and when the tube was passed between 
the valves, and gently rubbed against their edges, a sound re¬ 
sembling the ‘bruit de rape ’ was heard. 
The foregoing experiments were frequently repeated, and the 
observations were confirmed. 
§ 3. Conclusions respecting the Motions of the Heart . 
From the preceding experiments on the motions of the heart 
the following conclusions may be drawn. 1. In the heart of 
warm-blooded animals the systole of the ventricles follows, im- 
mediately, the systole of the auricular appendices, 2. During 
the systole of the ventricles the auricles are distended by blood 
passing from the venous trunks. 3. The ventricles, when 
their systole has ended, become relaxed and flaccid, and the 
blood passes rapidly, but with little force, from the auricles 
intotheir cavities. 4. The auricles are never emptied of blood, 
and contract but little on their contents; an active con¬ 
traction being observable only in their appendices. 5. If the 
interval between two successive beats of the heart be regarded 
as divided into four equal parts, two of those parts may be 
allotted to the duration of the ventricular systole, rather less 
than one part to the interval between the end of the ventricular 
systole and the commencement of the diastole of the appendices, 
during which interval little motion is observable in the auricles, 
and the remaining portion may be allotted to the diastole and 
systole of the auricular appendices. 6. The ventricles, in their 
systole, approach the front of the thorax, and by their contact 
and pressure against it produce the impulse, or ‘beat’ of the 
heart. 7* The beat of the heart and pulse in the arteries are 
synchronous only when the pulse is felt in arteries close to the 
heart: in those at a distance the pulses are later than the beat 
of the heart by intervals of time proportioned to the distances. 
In the heart of the frog, which was examined in the fourth 
experiment, the ventricle swelled and approached the sternum 
