f the skull, his technique has been little
improved upon even in modern times. In one of these operations he
successfully removed a portion of a man's brain.

Surgery was undoubtedly stimulated greatly at this period by the
constant wars. Lay physicians, as a class, had been looked down
upon during the Dark Ages; but with the beginning of the return to
rationalism, the services of surgeons on the battle-field, to remove
missiles from wounds, and to care for wounds and apply dressings, came
to be more fully appreciated. In return for his labors the surgeon was
thus afforded better opportunities for observing wounds and diseases,
which led naturally to a gradual improvement in surgical methods.

FIFTEENTH-CENTURY MEDICINE

The thirteenth and fourteenth centuries had seen some slight advancement
in the science of medicine; at least, certain surgeons and physicians,
if not the generality, had made advances; but it was not until the
fifteenth century that the general revival of medical learning became
assured. In this movement, naturally, the printing-press played an
all-important part. Medical books, hitherto practically inaccessible
to the great mass of physicians, now became common, and this output of
reprints of Greek and Arabic treatises revealed the fact that many of
the supposed true copies were spurious. These discoveries very naturally
aroused all manner of doubt and criticism, which in turn helped in the
development of independent thought.

A certain manuscript of the great Cornelius Celsus, the De Medicine,
which had been lost for many centuries, was found in the church of St.
Ambrose, at Milan, in 1443, and was at once put into print. The effect
of the publication of this book, which had lain in hiding for so many
centuries, was a revelation, showing the medical profession how far
most of their supposed true copies of Celsus had drifted away from the
original. The indisputable authenticity of this manuscript, discovered
and vouched for by the man who shortly after became Pope Nicholas V.,
made its publication the more impressive. The output in book form of
other authorities followed rapidly, and the manifest discrepancies
between such teachers as Celsus, Hippocrates, Galen, and Pliny
heightened still more the growing spirit of criticism.

These doubts resulted in great controversies as to the proper treatment
of certain diseases, some physicians following Hippocrates, others Galen
or Celsus, still others