nized a connection between the beating heart and the
blood flowing through it, his interest having been quick-
ened by Fabricius’s work on the valves in the veins and
VESALIUS’s De humani corporis fabrica (On the structure of
the human body). He returned to London (1604) to prac-
tice medicine and was appointed (1609) to St. Bar-
tholomew’s Hospital, where he remained for 34 years.
During this period he served as physician to both James I
and Charles I while continuing his own scientific research,
which culminated in his discovery of the true function of
the heart as the pump that circulates the blood. The pub-
lication of his De motu cordis et sanguinis in animalitus (On
the motion of the heart and blood in animals; 1628) made
him famous throughout Europe.
After attending King Charles and his sons at the bat-
tle of Edgehill (1642) in the Civil War, Harvey was ap-
pointed warden of Merton College, Oxford. Here he
resumed his research on the development of chicks in
hens’ eggs, which led to the publication of De generatione
animalium (On the generation of living creatures; 1651).
However, he did not avail himself of a microscope for this
work and so was unable to see spermatozoa; although he
was led to reject the Aristotelian theory of spontaneous
generation, his own interpretation is unclear. He died of a
stroke at age 80.
Further reading: Roger French, William Harvey’s Nat-
ural Philosophy (Cambridge, U.K.: Cambridge University
Press, 1994).
Hassler, Hans Leo (1564–1612) German composer
Born in Nuremberg, he received his earliest musical train-
ing from his father. In 1584 he became one of the first
German musicians to study in Venice, as a pupil of Andrea
GABRIELI. In 1586 he was appointed chamber organist to
Octavian II Fugger in Augsburg, where he published many
works and established a wide reputation. In 1600 he re-
turned to Nuremberg as director of the town’s music. In
1604 he moved to Ulm, and in 1608 was appointed cham-
ber organist to Christian II, Elector of Saxony, in Dresden.
He died in Frankfurt as court Kapellmeister.
Though a Protestant, Hassler’s early works are all for
the Roman rite. His Masses and motets show the influence
of the Venetians in their polychoral techniques and rich
sonorities. He was also famous for his Italian madrigals
and canzonettes. His rather conservative German church
music, though often using Lutheran melodies, shows the
influence of LASSUS. His lieder were widely known; the
tune of his love-song, “Mein G’müt ist mir verwirret”
(1601), was used for the Lutheran hymn, “O Haupt voll
Blut und Wunden” which features in J. S. Bach’s St.
Matthew Passion.Hebrew studies Curiosity about the Hebrew language
dates in Western Christendom from the time of the
Church Fathers, notably St. Jerome (337–420). During the
Middle Ages, Hebrew’s unfamiliar alphabet was thought
by many Christians to possess talismanic powers, but iso-
lated scholars, with the aid of learned Jews, did pursue the
subject more seriously. In 13th-century France and Spain
public disputations between Jews and Christians on mat-
ters of faith disseminated some knowledge of Jewish
thought, but too often resulted in increased ANTISEMITISM
and the burning of Hebrew books. The object of the
Hebrew studies of such men as Robert Grosseteste
(1175–1253) and Roger Bacon (c. 1213–c. 1294) was pri-
marily the conversion of the Jews. Orthodox Jews contin-22332 2 HHaasssslleerr,, HHaannss LLeeooWilliam HarveyAn engraving showing
Harvey’s experiments on the circulation
of the blood. The arms, with tourniquets
applied, show the blood vessels and the
pressure points.
© Bettmann/CORBIS