t's action, and it is, as before stated, from these sounds, from
tracings of the pulse, and from the many other indications, that we
arrive at a diagnosis. Thus, in obstruction of the orifice at the
junction of the aorta with the left ventricle, one of the most frequent
of valvular lesions, a murmur, generally harsh in character, is heard
with the first sound of the heart, with greatest intensity directly over
the normal position or the aortic semilunar valves. This is conveyed
along the large arteries, and may be heard, less distinctly, over the
carotids. In the sphygmographic tracing, the line of ascent is less
abrupt than in the normal tracing (Fig. 2), and not nearly so high, and
it is rounded at the top. In aortic regurgitation, the line of ascent is
similar to that of the healthy tracing, but the line of descent is very
sudden. The left side of the heart is almost invariably the primary seat
of these affections, but in the latter stages of their course, the right
side also is liable to become involved, and, as a consequence, there
then exists great disturbance of the venous circulation, with a damming
back of the blood in the veins, and passive congestion of the liver,
kidneys and brain, followed by dropsy, albumen in the urine, etc.

[Illustration: Fig. 2.
The above is a representation of a tracing of a healthy
pulse as made with the Sphygmograph.]

HYPERTROPHY OF THE HEART consists of a thickening of the muscular walls
of this organ. It may be confined to one portion of the heart, or it may
affect the entire organ. The affection has been divided into the
following three forms: _Simple hypertrophy_, in which there is an
increase in the thickness of the walls of the heart, without any
augmentation in the capacity of the cavities, and which is usually the
result of chronic Bright's disease, or great intemperance; _eccentric
hypertrophy_, in which there is an increase in the thickness of the
walls of the heart, together with increase in the capacity of the
cavities, and which is generally the result of some valvular lesion; and
_concentric hypertrophy_, in which there is an increase in the thickness
of the walls of the heart, with a decrease in the capacity of the
cavities. Valvular lesions, obstructions in the large arteries, or, in
fact, any thing which calls upon the heart to constantly perform an
undue amount of labor must, necessarily, produce hypertrophy of its
muscular walls, just as the undue amount of labo