DISCOVERY OF X-RAYS
reading this section you will be able to do the following:
how Roentgen discovered the X-ray.
the impact Roentgen's discovery had on the world at that time
(1895), and then compare it to the impact it still has today.
discovery of X-rays
late 1895, a German physicist, W. C. Roentgen was working with
a cathode ray tube in his laboratory. He was working with tubes
similar to our fluorescent light bulbs. He evacuated the tube
of all air, filled it with a special gas, and passed a high electric
voltage through it. When he did this, the tube would produce a
fluorescent glow. Roentgen shielded the tube with heavy black
paper, and found that a green colored fluorescent light could
be seen coming from a screen setting a few feet away from the
tube. He realized that he had produced a previously unknown "invisible
light," or ray, that was being emitted from the tube; a ray
that was capable of passing through the heavy paper covering the
tube. Through additional experiments, he also found that the new
ray would pass through most substances casting shadows of solid
objects on pieces of film. He named the new ray X-ray, because
in mathematics "X" is used to indicated the unknown
In his discovery Roentgen found that
the X-ray would pass through the tissue of humans leaving the
bones and metals visible. One of Roentgens first experiments
late in 1895 was a film of his wife Bertha's hand with a ring
on her finger (shown below on right). The news of Roentgens
discovery spread quickly throughout the world. Scientists everywhere
could duplicate his experiment because the cathode tube was very
well known during this period. In early 1896, X-rays were being
utilized clinically in the United States for such things as bone
fractures and gun shot wounds.
Take a look at
these early x-rays.
were discovered by William Roentgen while experimenting with
a cathode radiation .