Slice of History: X-Rays Discovered: Nov. 8, 1895

A few days after noticing something odd in his laboratory, German physicist Wilhelm Roentgen set up an experiment late on a Friday afternoon.  He sent an electrical charge through a tube wrapped in heavy black paper.  Just as he thought he had noticed previously, he saw clearly that somehow the light has passed through the paper and was creating a fluorescent glow on a chemically-coated screen several feet away. 

Roentgen realized that he had discovered a different type of ray—he called it an X-ray—one that could pass through substances and cast a shadow of solid objects on pieces of film.

He spent the next few weeks working secretly in his lab--he wanted as much proof as possible that X-rays existed before going public with his discovery.  Then he produced the first X-ray, an image of his wife's hand that revealed the bones inside. When she saw it, she exclaimed, "I have seen my death."

By the end of the year, Roentgen published his first paper on X-rays, titled "On a New Kind of Rays" and early in 1896, an Austrian newspaper reported his discovery, noting that the new kind of radiation could have a profound impact on medical diagnosis.

A few days later, Roentgen demonstrated how X-rays worked to Kaiser Wilhelm II in a private meeting and then, at a session of the Wurzburg Physical Medical Society on January 23, he presented his findings and X-rayed the hand of one of the doctors present. The physician was so impressed that he suggested that the name of the radiation be changed to "Roentgen rays," but the name didn't stick.

News of Roentgen's discovery spread quickly through the medical world and, within months, doctors were using X-rays to examine broken bones and gunshot wounds.  Soon, X-ray departments were being set up at hospitals, such as the Glasgow Royal Infirmary in Scotland, where doctors not only produced the first X-ray of a kidney stone, but also the first one of a penny caught in a child's throat.  By 1897, X-rays were being used to diagnose battlefield wounds during the Balkan War.

While scientists were quick to realize the benefits of X-rays, they were much slower to comprehend the harmful effects of the radiation. Initially, it was believed X-rays passed through flesh as harmlessly as light. However, within several years, researchers began to report cases of burns and skin damage after exposure to X-rays, and in 1904, Thomas Edison's assistant, Clarence Dally, who had worked extensively with X-rays, died of skin cancer. Dally's death upset Edison so much that he stopped all of his own research on X-rays.

But it wasn't until the 1930s that scientists first recommended lowering exposure to X-rays. By then Roentgen was dead, a victim of intestinal cancer.  Although he was awarded the first Nobel Prize in Physics in 1901, he died a poor man. He had never tried to patent his discovery, and what little fortune he had was wiped out by the runaway inflation in Germany after World War I.

Today, Roentgen's discovery is widely used in medicine, material analysis and, of course, devices such as airport security scanners.  It's estimated that more than five billion X-rays are done every year.

More Slices of History

A Killer Smog: Oct. 27, 1948

1st Modern Plastic Surgery: Oct. 23, 1814

Columbus Discovers Tobacco:  Oct. 15, 1492

1st U.S. Insane Asylum:  Oct. 12, 1773

Thalidomide Goes on Market: Oct. 1, 1957