d one-half inches to
the right half of the cavity of the chest.

Size: In adults it is five inches long, three and one-half inches in
breadth at its broadest part and two and one-half inches in thickness.
Weight in the male ten to twelve ounces; in the female eight to ten. It
increases up to an advanced period of life. The tricuspid valve (three
segments) closes the opening between the right auricle and right
ventricle. Pulmonary semilunar valves guard the orifice of the pulmonary
artery, keeping the blood from flowing back into the right ventricle. The
mitral valve guards the opening to the left ventricle from the left
auricle. The semilunar valves surround the opening from the left ventricle
into the aorta and keep the blood from flowing back. If any one of these
valves becomes diseased it may not thoroughly close the opening it is
placed to guard and then we have a train of important symptoms.

[CIRCULATORY DISEASES 341]

PERICARDITIS.--This is an inflammation of the pericardium, the sac
containing the heart.

Primary or First Causes.--They refer in this disease to a peculiar
constitution. Children that have a tuberculous constitution are more
liable to this disease. Acute rheumatism or tonsilitis are the causes and
this trouble follows or goes with them. Infectious diseases also cause it.

Symptoms.--Slight pain in the heart region, fever moderate. These subside
or effusion may set in and this usually occurs with acute rheumatism,
tuberculosis and septicemia. Sometimes these symptoms are absent.

Treatment of Pericarditis.--The patient must rest quietly in bed and a
doctor should be in attendance. An ice bag placed over the heart
frequently gives relief and quiets the distress and pain. There is apt to
be liquid in the sac (pericardium) and to lessen the tendency to this
there should not be much drink or liquid food taken. There should be what
is called a dry diet. (See Nursing Department for this.)

ENDOCARDITIS.--Inflammation of the lining of the heart chiefly confined to
the valves; it may be acute or chronic.

Simple Kind, Cause.--Occurs at all ages, but most often in children and
young adults. It most frequently comes with acute rheumatism, chorea,
tonsilitis, scarlet fever, and pneumonia. The valves in the left heart are
most often affected, the mitral simply swollen or bearing small growths.

Symptoms.--If it is caused by acute rheumatism, there may be higher
temperature, without increase of jo