Photos: X-Ray History—Hidden Kittens, Quackery, and More

115-Year-Old X-Ray
Image by Wilhelm Röntgen, via SSPL/Science Museum/Getty Images
This 115-year-old picture of fingers is one of the first images ever made with x-rays, whose discovery is being feted Monday with an anniversary Google doodle. (See "X-Rays on Google: Surprising Ways the Rays Are Used Today.")
The hand belonged to Anna Bertha, wife of German physicist Wilhelm Röntgen, the discover of x-rays. The black glob on the fourth finger is a ring made of gold, which absorbs x-rays.
Röntgen stumbled across x-rays on November 8, 1895, while experimenting with an early vacuum tube known as a Crooke's radiometer. He noticed that, when the cathode rays from the tube struck the end of a discharge tube, a previously unknown type of radiation that could penetrate matter was emitted.
Röntgen created the picture of his wife's hand using the unknown, or x, rays a few days later.
"She apparently was not impressed by his photography," said Martin Richardson, a professor of optics at the University of Central Florida, whose group has been helping to pioneer the use of x-ray microscopy for biological studies since the early 1990s.
According to some accounts, Anna exclaimed "I have seen my death!" after seeing the now famous image.
(Related: "Iceman Bled Out From Arrow Wound, X-Rays Reveal.")
—Ker Than
Published November 8, 2010
X-Rays Target Presidential Bullet
Image courtesy Library of Congress
A medical x-ray shows the rib cage of U.S. President Theodore Roosevelt after an attempted assassination in 1912 in Milwaukee, Wisconsin, where he was campaigning. The nonfatal bullet was never removed.
This radiograph—a picture made on film that's sensitive to radiation other than visible light—shows that x-rays were already being used for medical imaging only 17 years after Wilhelm Röntgen's first experiments with the radiation.
Published November 8, 2010
X-Rays: Good for What Ails You?
Image courtesy Edwin S. Gerson, RSNA
X-rays took the world by storm after their discovery. This ad from 1896 describes a headache remedy called Kohler's Antidote as a dose of "x-ray exposure"—though the medicine didn't emit any x-rays.
Advertisers were quick to associate their products with the term "x-ray." In addition to headache medicines, there were x-ray golf balls, x-ray stove polish, x-ray prophylactics, and x-ray shaving razors. (Read more about "x-ray mania" in the RadioGraphics journal.)
Published November 8, 2010
X-Rays Reveal Art Under Art
Photograph by Franco Origlia, Getty Images
Today, art historians routinely use x-rays to peer beneath the finished surfaces of paintings—such as Caravaggio's 17th-century masterpiece "Adoration of the Shepherds" (shown)—to reveal rough sketches or "underdrawings" and to discover changes that the artist made during the painting process.
(Related: "Hundreds of Dino-Era Animals in Amber Revealed by X-Rays.")
Published November 8, 2010
X-Rays Find Inner Kitten
Photograph by Richard Barnes, National Geographic
X-rays can also be used as a noninvasive way of peering inside priceless artifacts, such as this ancient Egyptian wooden cat coffin, which was found to hold the corpse of a kitten. (See more pictures of animal mummies.)
(Related pictures: "'Invisible' Ancient Bugs Seen by Hi-Tech X-Rays.")
Published November 8, 2010
X-Rays in Space
Image courtesy NASA
Snapped by NASA's Einstein Observatory, which launched in 1978, this speckled image is one of the first x-ray space telescope images of a cosmic object ever taken.
Also known as the High Energy Astronomy Observatory (HEAO)-2, the Einstein Observatory was the largest x-ray telescope of its day. It was also the first one capable of producing actual photographs of x-ray objects.
More than a dozen x-ray telescopes have been launched into space so far. With their aid, astronomers have discovered x-ray sources far beyond our solar system, including distant galaxies and black holes. (Find out how x-rays are unlocking black hole mysteries.)
While black holes themselves emit no light, the environments immediately surrounding black holes are often so turbulent that they shine brightly in x-rays.
"What seems to be happening is that black holes accumulate large disks of infalling matter around them," said Leon Golub, an astrophysicist at the Harvard-Smithsonian Center for Astrophysics in Cambridge, Massachusetts.
"As that matter swirls around the black hole and spirals towards its center, it heats up, and the gas gets so hot that it becomes like the corona [of a star] and it produces x-rays."
Published November 8, 2010
X-Rays Easy on the Eyes?
Advertisement from the February 1917 National Geographic, used under public domain
This ad from the February 1917 issue of National Geographic extols the virtue of so-called X-ray Reflectors.
There was a time shortly after their discovery that x-rays were as popular as lasers are today, according to Edwin Gerson, a radiologist in Riverdale, Georgia, who collects 19th- and 20th-century "x-ray products."
"Everyone focused on the x-ray as an unexpected technologic advancement that encouraged belief in other similar or even more miraculous advances," Gerson wrote in a 2004 article for the journal Radiographics.
"Hence, the x-ray became exemplary of the better future that all might experience. The x-ray extended the normal human senses and promised to improve quality of life. What product would not benefit from such subconscious association?"
Published November 8, 2010
X-Ray Crab
Photograph by Nick Beasey, National Geographic
As this radiograph image of a crab shows, x-rays can make the familiar seem alien. This image by Nick Veasey appeared in the book X-ray: See Through The World Around You and in the October National Geographic magazine. (See more of Nick Veasey's x-ray pictures.)
On the 115th anniversary of x-rays' discovery, scientists are still devising new ways of using the radiation, the University of Central Florida's Richardson said.
"Although Röntgen discovered x-rays 115 years ago," he said, "x-ray science is very far from a dead science."
Published November 8, 2010