I
N THE DAYS
following his
discovery of a
new, invisible ray in
November, 1895,
Professor Wilhelm
Conrad Roentgen
experimented doggedly
to test its properties.
He noted quickly that
solid objects placed in
the beam between the
Crookes’ tube and the
fluorescent screen
serving as an image
receptor attenuated or
blocked the beam,
depending upon their
density and structure.