Featured History: Wilhelm Röntgen  


“I didn’t think; I investigated.”

So said Wilhelm Röntgen when asked what he was thinking on November 8, 1895, at the moment he discovered X-rays. His investigations and the resulting paper, “On a New Kind of Rays,” took the world by storm, revolutionized medicine, and earned him the first Nobel Prize in Physics in 1901 (1).

But when Wilhelm first began his career, all of that was far from anyone’s mind. Born in 1845 in Germany, Wilhelm was the only child of Charlotte Constanze Frowein and Friedrich Conrad Röntgen, a merchant and manufacturer of cloth. When Wilhelm was three years old, his family moved to Holland, where his mother’s family lived. There he attended school until his late teens, when he was expelled from the Utrecht Technical School for refusing to reveal who had drawn an unflattering caricature of a teacher (2).

House in

The house in Remscheid-Lennep, Germany, where Röntgen was born.

Without that diploma, Wilhelm was not qualified to matriculate at German universities, but after hearing that he could enter the new Federal Polytechnic Institute in Zurich by passing one exam, he moved there and began studying mechanical engineering (1). From that point, Wilhelm’s career took off, landing him a Ph.D. in experimental physics in 1869 and a lecturing position at the University of Strasbourg in 1874. Over the next several years, he leapfrogged all over the region, moving to Württemburg in 1875, back to Strasbourg in 1876, to Giessen in 1879, and to Würzburg in 1888. Though he was offered many other prestigious positions, it was in Munich that he finally settled down, after the Bavarian government asked him to chair the University of Munich’s physics department in 1900 (2).

Between moves, Wilhelm found the time to marry Anna Bertha Ludwig, whom he had met at her uncle’s cafe in Zurich. Though they never had any children, they did adopt Anna’s brother’s six-year-old niece, Josephine, in 1886. The family took annual hiking trips to Switzerland, during which their friends and relatives remember Wilhelm as “forever moving about” with his beloved box camera and black hood (3).

L0000622EB Radiograph of hand by W.K. Roentgen

Radiograph of Anna’s hand, December 1895.

It was this hobby, some say, that made all the difference in 1895, when Wilhelm noticed that a coated cardboard screen in his lab was glowing, although he had thought it was too far from his covered cathode ray tube to be affected. He was by no means the first person to notice how certain rays made other materials fluoresce; in fact, his cathode ray tubes had been developed by and borrowed from another physicist, Philipp Lenard. A full five years earlier, American physicist Arthur Goodspeed had left two coins on some photographic plates near a Crookes tube, then noticed that the developed plate showed two mysterious circles. The differences in Wilhelm’s work were that he followed up on his discovery, investigating the rays’ origin and effects — and captured stunning images that seized the public’s attention and imagination when they were featured in Neue Freie Presse, a popular Viennese newspaper, on Sunday, January 5, 1896 (3).


Radiograph of six substances, December 1895.

Though Wilhelm Röntgen made his discovery through seven weeks of solitude, keeping his work secret from his assistants and wife (who reportedly accepted her husband’s sudden reclusiveness calmly, interrupting only to bring him meals), the discovery was anything but a quiet affair the instant it was published. The public immediately seized upon the new technology, in many cases building their own devices from easily acquired materials (3). But the story of X-rays influence on society is one for another time. For now, it is enough to realize that the many acclamations showered on Röntgen (including giving his name to a unit of radiation exposure, the 111th element, and several streets) are hardly enough to recognize this one man’s contribution to science and the possibilities he unleashed with one casual glance at a cardboard screen.

Wilhelm_Conrad_Roentgen_looking_into_an_X-ray_screen_placed_Wellcome_L0027361 (2)

“Wilhelm Conrad Roentgen looking into an X-ray screen placed in front of a man’s body and seeing the ribs and the bones of the arm. Chromolithograph.”


Sources Used:

(1) “This Month in Physics History: November 8, 1865: Roentgen’s discovery of X-Rays.” Ed. Alan Chodos. American Physical Society. Web. 1 Jan. 2015 <http://www.aps.org/publications/apsnews/200111/history.cfm>

(2) “Wilhelm Conrad Röntgen – Biographical”. Nobelprize.org. Nobel Media AB 2014. Web. 4 Jan 2015. <http://www.nobelprize.org/nobel_prizes/physics/laureates/1901/rontgen-bio.html>

(3) Kevles, Bettyann Holtzmann. Naked to the Bone: Medical Imaging in the Twentieth Century. New Brunswick, N.J.: Rutgers University Press, 1997.


Image Sources:

Portrait by Fotogravyr General Stabens Litografiska Anstalt [Public domain], via Wikimedia Commons.

House photograph by Markus Schweiss (Own work) [GFDL (http://www.gnu.org/copyleft/fdl.html) or CC-BY-SA-3.0 (http://creativecommons.org/licenses/by-sa/3.0/)], via Wikimedia Commons.

Substances radiographhand radiograph, and illustration from Wellcome Trust, a website operated by Wellcome Trust, a global charitable foundation based in the United Kingdom, via Wikimedia Commons.