hat the veins return the blood to
the heart from all parts of the body. That such is the case might be
inferred from the presence and disposition of the valves in the veins;
for the office of the valves is by no means explained by the theory that
they are to hinder the blood from flowing into inferior parts by
gravitation, since the valves do not always look upwards, but always
towards the trunks of the veins, invariably towards the seat of the
heart. The action of the valves is then demonstrated experimentally on
the arm bound as for blood-letting. The point of a finger being kept on
a vein, the blood from the space above may be streaked upwards till it
passes the valve, when that portion of the vein between the valve and
the point of pressure will not only be emptied of its contents, but will
remain empty as long as the pressure is continued. If the pressure be
now removed, the empty part of the vein will fill instantly and look as
turgid as before.

Other confirmatory evidence is then added, e.g. the absorption of animal
poisons and of medicines applied externally, the muscular structure of
the heart and the necessary working of its valves.

William Harvey, the illustrious physiologist, anatomist, and physician,
to whom this discovery is due, was the eldest son of a Kentish yeoman,
and was born in April, 1578. At the age of ten he entered the Canterbury
Grammar School, where he appears to have remained for some years. At
sixteen he passed to Caius-Gonvil College, Cambridge, and three years
afterwards took his B.A. degree and quitted the university. Like most
students of medicine of that day, he found it necessary to seek the
principal part of his professional education abroad. He travelled to
Italy, selected Padua as his place of study, and there continued to
reside for four years, having as one of his teachers the famous
Fabricius of Aquapendente. On his return to England, in 1602, he took
his doctor's degree at Cambridge, and entered on the practice of his
profession.

In 1604 he joined the College of Physicians, and three years later was
elected a Fellow of that learned body. Two years afterwards he applied
for the post of physician to St. Bartholomew's Hospital; and his
application being supported by letters of recommendation to the
governor, from the king and from the president of the College of
Physicians, he was duly elected to the office in the same year, as soon
as a vacancy occurred.

In 1615, when thi