ON THE MOTIONS AND SOUNDS OF THE HEART. 201 
rounding and shortening in systole. And after opening the ven- 
tricles the left seemed the larger of the two. 
The wave-like motion, or sensation as of an undulation from 
fundus to apex in systole, was very distinct. 
OxgsERVATION XXIII. 
August 24.—A Dog (bull-dog terrier), one to two years old, 
stunned, and chest artificially inflated. 
Phenomena: Results of threading different parts of the ven- 
tricles, and at the same moment pressing the threaded parts 
with the finger, and pulling at them by means of the thread, 
showing the mechanism of the heart’s throb ;—rhythm of cardiac 
and aortic pulsations ;—results of introducing a tube into the 
cava ;—respiratory suction ;—venous regurgitation in systole ; 
—phenomena of the heart’s action out of the body both as to 
motions and sounds. 
S. 1. The heart was laid bare and a thread was passed 
through the apex cordis, and a second through the parietes 
nearly over the mitral orifice, and traction was exerted on each 
string in a direction outwards, and away from or vertical to the 
point of insertion, and the result was that in each systole each 
string was felt to be pulled and rendered tense, and to become 
lax in diastole. At the moment of tension in each chord the 
_ finger was placed on the point at which each respectively had 
been introduced, and the result was a double sensation, viz. 
1. That of traction in the chord, indicating contraction of the 
heart. and mutual approximations of its extremities, and, 
2. that of outward impulse in the point of the parietes under 
the finger (indicating, as the Reporter conceived, the undulation 
of the blood reacting against the compressing parietes of the 
_ ventricles). 
' 8.2. The attachments of the vessels or muscular parts in- 
serted into the roots of the arteries, especially the pulmonary 
artery, were observed very distinctly to approximate slightly 
towards the apex in each systole, and to recede from the apex 
in diastole. 
_ §.3. A barely perceptible difference in time was detected 
between the systole of the left ventricle and diastole of the 
aorta—no distinct interval however. 
8.4. A glass tube was introduced into the lower cava, and 
a column of blood obtained, which oscillated frequently, but 
not in accordance with the heart’s motions. These oscillations 
were attributable (the Reporter conceived) to irregular, spas- 
modic, respiratory efforts, occurring in the right side of the 
chest, which was still air-tight, the mediastinum being still 
