Paris, in the uniform of one of the Hitler Youth, selects the epitome of Aryan beauty.

In 1908 two young men arrived in Vienna with the intention of studying art. In what may represent the worst admissions decision of all time, one of those men was rejected and ended up finding an altogether more sinister destiny. The other, Ivo Saliger, was not only admitted, but ultimately rose to the rank of professor. Sadly, fate was not done with her cruel jest and when the failed artist became the most powerful figure in a nation of madmen the professor found himself painting garbage to fulfill the desires of his tasteless masters. Amongst such pieces was the much praised Judgment of Paris in which the youthful Paris judges between the beauty of Athena, Aphrodite, and Hera. The twist? Paris is dressed in the costume of the Hitler Youth and the goddesses all represent the ironic concept of Aryan beauty. It must have been a challenge for Saliger, whose art suggests a sensitive and compassionate soul and who created such moving works as Der Arzt in which a doctor tries to defend a young woman (representing Saliger’s own sister, who died of leukemia) against death or the Kafkaesque Justice in which a fearsome advocate protects his client against an angry crowd. Not so challenging, admittedly, that he was willing to forego the rewards of making art for the Nazi elite.

“I portrayed the face of the physician with a skepticism, an uncertainty, whether the fight will end well or not.” – Ivo Saliger

This is kind of what it feels like when you save a life at three in the morning.

Nonetheless, for entirely selfish reasons, I possess a fondness for Saliger and above my desk hangs a reproduction of his etching The Physician of the X-Rays. It was composed in between the World Wars and is one of the few depictions I’ve ever seen of a radiologist illuminated by the hagiographic light usually reserved for surgeons and dictators. Even here, sadly, the radiologist is a rather gormy-looking character with his bald pate and eyes made insect-like from goggles. Though with his mighty x-rays he is effectively banishing the skeletal personification of Death, and though his comely patient is so relieved that she has discarded all modesty; it is hard not to imagine that once the immediate threat is past she’ll find some excuse not to embrace her brainy savoir. Still, we radiologists have learned to take what little glory we can in a world where most people: don’t realize that radiologists are doctors (we are, and with an additional five or more years of specialized radiology training after medical school); assume that we take x-rays (we don’t, radiology technologists working under our direction do); and believe that their regular doctors interpret x-rays, CT scans, MRIs, and ultrasounds (most don’t, the radiologist provides them a reading – those that do probably shouldn’t; just as a radiologist shouldn’t perform surgery). It’s a sad state of affairs for the guardians of history’s second most important medical advance (bested only by antibiotics, if perhaps rivaled by anesthesia and antiseptics). But we do take comfort in the fact that even if you don’t know we exist, we’re probably going to play a huge role in your diagnosis. Also, we have the best toys – and in the next few pages I’m going to share some of the history and mechanics of the devices that allowed the first radiologists to harness x-rays, and the great price many of those pioneers paid.

There would be more radiologists if they showed this during the first week of medical school.

The Discovery of Invisible Light

Roentgen’s credit is not because he was the first person to observe the effects of x-rays, but rather because he realized that those effects were in fact caused by a distinct phenomenon.

Assigning precedence for a scientific breakthrough is always a contentious business. Every momentous discovery is actually founded on prior research and usually multiple researchers are all sniffing around a particular idea when one of them finally shouts “Eureka!” The discovery of x-rays is no different. Although in this case the creative histories of black-gloved Nazis, the involvement of Tesla, and the destruction of the laboratory notes of the central figure make the case particularly difficult to put back together.

What is clear is that in the late 19th century many scientists and inventors were experimenting with the passage of electricity through vacuum tubes. The scientific world was abuzz with talk of cathode rays. Only later were these appreciated to be beams of electrons moving within vacuum tubes between a cathode and an anode. However, whether they realized it or not, any of those scientists using sufficiently powerful tubes were generating x-rays because, as we’ll discuss shortly, while some of the electrons were flying out of the glass tube or energizing gas within it, others were colliding with the anode or the glass and giving off x-rays as a byproduct of their deceleration.

The first conscious radiograph of a human was taken by Roentgen of his wife’s hand.

Cathode rays were known to cause phosphorescent materials to glow and to expose photographic plates at very short distances from the vacuum tubes. However, their potency dropped off precipitously at more than a few centimeters from the tube. Several researchers including (but not limited to) Arthur Goodspeed, Nikola Tesla, Johann Hittorf, and Philipp Lenard had all intentionally or inadvertently exposed photographic plates at far greater remove. But none of them made the connection that whatever was exposing these plates at a distance was something other than the cathode rays.

“I did not think. I investigated.” -Wilhelm Roentgen

The famous door in Roentgen’s lab through which x-rays passed – confirming his suspicion that they were a distinct from cathode rays whose range was far shorter.

On December 28th, 1895 he presented his famous monograph in which he coined the term “X” (after the algebraic unknown) “stralhen” (or ray) for the invisible emission. He forwarded copies of this paper widely and gave two additional presentations in January – first to the German Emperor and then to his colleagues in Wurzburg during which he demonstrated his apparatus and took another famous hand radiograph (the “two ring” plate) of Professor Albert von Kolliker. It was Kolliker who suggested the rays be henceforth called Roentgen rays (a title which persists in a few locales though most of the rest of the world uses Roentgen’s own preferred title of x-rays. Personally, I remain disappointed that the name suggested by Silvanus Thompson and initially favored by Edison, “ultraviolet sound,” didn’t catch on – although aether-strahlen and Tithonic rays also have nice rings to them.)

“In reality, science, like every other human product, is racial and conditioned by blood.” – Philip Lenard, who oversaw the purges of Jewish scientists from the German scientific establishment and used his position to undermine Roentgen’s reputation, describing him as a “friend of the Jews.”

Tesla was perhaps closer than anyone to beating Roentgen. However, he happily conceded the primacy of the discovery – and went on to make engineering contributions to radiology that remain relevant today.

For his discovery Roentgen received international praise including the very first Nobel Prize in Physics. Unfortunately, questions of priority dogged him and dramatically undermined his reputation during his lifetime particularly within his native Germany. Next to Roentgen, Tesla was probably the closest to appreciating the significance of x-rays as he seems to have believed something other than cathode rays was involved in the production of his evocatively named “shadowgrams.” Perhaps, had his work not been interrupted by a laboratory fire, he would have made the discovery and his own subsequent history might have been very different. However, he did not and, in contrast to some of his more ardent partisans, he seemed content with Roentgen’s priority. This, given that Tesla was hardly one to back away from demanding credit when he thought it was his due, seems to be the best evidence that he hadn’t made the critical realization that x-rays were a distinct beast from cathode rays.

Philipp Lenard was not as conciliatory as Tesla. Despite winning his own Nobel in 1905 for his work on cathode rays, Lenard was obsessed with his belief that his research and equipment were more important contributors to the discovery of x-rays than Roentgen’s. This became relevant in the 1920’s and 30’s after Roentgen’s death when Lenard, an early adopter of Nazism, rose to prominence. In addition to overseeing the purge of “non-Aryan” scientists from the German Academy, he campaigned extensively against Roentgen, labeling him as a “friend of the Jews.” He also supported the case of Roentgen’s laboratory assistant who asserted that he, not Roentgen, had first noticed the distant illumination caused by the x-rays. (While much was made of this toward the end of Roentgen’s life, to his despair, the reality is that it is essentially irrelevant. As we have discussed, it was not the detection of vacuum tubes working at a distance that was Roentgen’s great contribution – it was the realization that it was something other than a cathode ray doing that work.) Though the unrepentant Lenard was spared execution after WWII on account of his advanced age, his contribution to Roentgen’s discovery was all but erased when the Allied investigator (and radiologist), Colonel Lewis Etter, found evidence that rather than using one of Lenard’s tubes for his fateful experiments, Roentgen had used a tube of the Crookes-Hittorf variety. How much Etter’s revision was itself influenced by Lenard’s odiousness will probably never be known, but it certainly is a satisfying ending.

“There is much to do, and I am busy, very busy.” – Wilhelm Roentgen

As a further counterpoint to the self-aggrandizing evil of Lenard, Roentgen is now lauded not just for his discovery, but for his selflessness. He donated all of the Nobel Prize reward money to his university and during The First World War he donated the gold medal itself to be melted down for the German war effort. Most importantly, he adamantly refused to patent his discovery. Despite the potential for staggering profits (that would be realized in the years to come by numerous manufacturers) he insisted that the fruits of his discovery belonged to humanity. Sadly, his generosity was not rewarded during his lifetime and he died a near penniless widower after the war. It was only to future generations that he became a medical hero, and in the years after his death that he became the patron saint of radiologists.

Roentgen, here just weeks before his death, died a haunted man. The personal jealousy of his rivals linked to nationalist politics resulted in Roentgen’s reputation being all but ruined in his home country.