Bringing the invisible to light

X-rays have fascinated people since 1896 – and they revolutionized medicine

On November 8, 1895, Wilhelm Conrad Röntgen, a scientist working at his lab in Würzburg, discovered a new kind of radiation, which he called “X-rays.” The rays penetrated materials and the human body to varying degrees and could be captured on a photographic plate.

The first medical imaging method was born. Unlike in conventional photography – from the Greek photos, for “light,” and graphos, for “drawing” – early X-ray images were more like shadow images. On December 22, 1895, Röntgen successfully produced the first X-ray image of the human body: the hand of his wife, Bertha.

Siemens MedMuseum x-ray imaging technology Hand Bertha Röntgen
X-ray image of the hand of Bertha Röntgen, 1895

Source: Deutsches Röntgen-Museum, Remscheid-Lennep

News of Röntgen’s discovery spread around the world like wildfire. On January 5, 1896, just a short time after the discovery itself, a detailed report was published in Vienna’s Die Presse. Numerous newspaper reports, public lectures and presentations also helped to popularize the mysterious rays. Being able to look inside people and things touched off a wave of “X-ray fever,” and X-ray images sprang up everywhere.

Kaiser Wilhelm II summoned Röntgen to Berlin to give him a personal report. The euphoria spread, and anything and everything was X-rayed: coin purses, luggage, human bodies. Just a few months after X-rays were discovered, fairs and public stages offered events promising audiences a never-before-seen spectacle. The mystery of taking images of a person’s own bones became a public attraction.

Röntgen himself believed his discovery was certainly important in scientific terms, but he was rather reticent in his comments about the possible practical applications of X-rays in medicine. But medical researchers were immediately thrilled about Röntgen’s discovery, viewing it as holding unimagined possibilities for diagnosing disease.

Siemens MedMuseum x-ray imaging technology W. C. Röntgen
Portrait of W. C. Röntgen, 1895

The new technology received an enthusiastic response in Erlangen, as elsewhere. The Erlanger Tagblatt newspaper reported on Röntgen’s “marvelous discovery” on January 10, 1896. Max Gebbert, owner of the Erlangen-based company Reiniger, Gebbert & Schall (RGS), recognized the new technology’s great potential. Just a few days after first hearing the news, he dispatched salesman Robert Fischer to Würzburg to learn about the process and procure “the necessary equipment for generating X-rays immediately.” Not long afterward, Gebbert hired two physicists to further develop the new technology: Dr. Willibald Hoffmann and Dr. Joseph Rosenthal.

Rosenthal was ultimately the person who designed a specific X-ray tube for medical diagnosis and had it produced by the company Emil Gundelach, in the German state of Thuringia. RGS launched its first X-ray equipment on the market later that same year. Rosenthal used it to take an image of a person’s head. He sent the picture to Röntgen in Würzburg, who wrote back, thanking him for “sending me the very nice photograph of a head.” The exposure time was 12 minutes.

Siemens MedMuseum x-ray imaging technology human skull
Image of the human skull taken by Dr. Joseph Rosenthal at RGS, 1896

In a letter to Gebbert dated November 27, 1896, Röntgen praises the good quality of the tubes, but also complains about the high price: “Your tubes are in fact very good, but too expensive for my circumstances... I would therefore like to ask if you could supply the tubes to me for Marks 20 instead of Marks 30...” Gebbert’s answer is lost to history, but another letter from Röntgen indicates that he was given the discounted price.

Siemens MedMuseum x-ray imaging technology letter Röntgen
Röntgen’s letter to RGS of November 27, 1896

Starting in the fall of 1896, Gebbert mounted “X-ray expeditions” to a number of larger cities in Germany, Austria, and Switzerland to demonstrate how X-rays worked. A salesman provided background information and reached out to potential customers, a technician operated the systems, and a physician explained the applications. Mayors and city council members, teachers and doctors were invited to these mobile demonstrations. At the same time, they brought the Erlangen-based company RGS to national and international prominence. The first few physician’s practices and hospitals were equipped with the new technology very soon afterward. The surgical clinic at the university medical center in Erlangen also received its first X-ray system that very same year, in 1896.

In the early years, operating X-ray equipment was complicated and required a great deal of experience. Initially, only doctors with a thirst for experimentation dared to try out the new apparatus, quickly developing a culture of expertise. Still, X-ray technology had a long way to go from those early labs to the standardized methods used in modern diagnostic facilities. Improved technology and diagnostic options changed the treatment situation time and again in the process.

W.C. Röntgen’s first publication: Eine neue Art von Strahlen (A New Kind of Rays), 1896
W.C. Röntgen’s first publication: Eine neue Art von Strahlen (A New Kind of Rays), 1896

Wilhelm Conrad Röntgen did not patent his discovery, as he wanted his inventions to be made accessible to the public rather than belonging to individual companies. He was the first scientist to be awarded the newly created Nobel Prize in Physics, in 1901. He donated the prize money – 50,000 Swedish kronor – to the University of Würzburg. Röntgen was so thorough in his research on X-rays that he had already discovered almost all of the properties of this form of radiation and described them in three publications.