“Chance favors the prepared mind” is the short form of a statement by Louis Pasteur which actually reads: “In the fields of observation chance favours only the prepared mind” or ” Dans les champs de l’observation le hasard ne favorise que les esprits prepares”. [1]
There is no better example of the wisdom of this phrase than the discovery of X-rays by Wilhelm Conrad Röntgen. When he worked with a vacuum tube he noticed the radiation-emitting feature of his experimental set-up almost immediately. Pictures of his wife’s hand and later, the hand of the famous anatomist Koelliker, showed the bony anatomy; news of his discovery made it around the world in record time.
Röntgen was not the first to experiment with the Crookes or Hittorf cathode ray tubes. Other scientists came very close to discovering X-rays but Röntgen’s publication in 1895 was the first. A prepared mind….
Arthur Willis Goodspeed, professor of physics at the Univ of Pennsylvania was probably the first to produce an X-ray image however he did not recognize the significance of his discovery. While tinkering with a Crookes tube at the University of Pennsylvania, he took an X-ray picture of a coin by accident. He kept the picture but did not pursue and investigate. When he learned about Röntgen’s paper, he reproduced his ‘coin X-ray’ confirming that it was not an artifact but a product of the same rays described by Röntgen. Later he quibbed that Röntgen’s ‘X-rays’ could have been known as ‘Goodspeed rays’. He stated that “Because of our laxity in not following the matter up we do not claim any credit whatsoever”. A case of a less prepared mind…[2]
While Goodspeed was gracious in defeat, others held grudges. The brilliant physicist Philip Lenard had collaborated with Röntgen and bitterly resented Röntgen’s fame and Nobel prize in 1901; although he was awarded a Nobel in 1903, the feud – highly politicized – continued till Lenard’s death in 1947.
FYI, pictures of Goodspeed’s coin X-rays are on display at the Peabody museum in New Haven. The history of Goodspeed’s ‘accidental’ discovery, the importance of which he had not recognized, is well described in various articles. Here are some references for the interested reader [3], [4]
In this blog we want to highlight two other aspects of Röntgen’s work.
First, his description of the physico-chemical characteristics of X-rays. His publication “Eine Neue Art von Strahlen” or ‘A new Kind of Rays” describes in amazing detail the character of these rays: attenuation by materials as a function of atomic density; lack of reflection, lack of convergence by lenses, and lack of deflection in strong magnetic fields.[5]
Röntgen soon followed up with a second publication providing further details [6]
Secondly, Röntgen did not take out a patent on his discovery – actually he refused to benefit financially. This made X-ray technology available for anyone to use, improve and monetize. News about X-rays spread with lightening speed as its use in medicine was obvious [7]. X-ray machines were seemingly everywhere in the Old and New World in record time. Case in point: the use of the new technology in Philadelphia, well documented for the turn of the century and later. In fact, the Pennsylvania Hospital in Philadelphia had an X-ray machine in 1897.
X-rays were used to take pictures of bones, fractures, foreign bodies but also for other purposes [8]. I was amazed to read that the famous violin virtuoso, Josef Joachim had a chest X-rays taken in Berlin prior to his death in 1907. His pulmonary findings were read by equally famous Berlin physicians who diagnosed pneumonia consistent with ‘actinomycosis’. How could anyone have come up with this diagnosis? Joachim was known to have a habit of chewing on grass leaves, hence the idea that his pulmonary infection could be caused by this slow-growing pathogen is not totally off-base. However, identification and classification of actinomyces spp were by no means established in 1907, even on culture. And we don’t know what was actually cultured. Another riddle wrapped in a mystery inside an enigma it seems.
REFERENCES
[1] Lecture, University of Lille (7 December 1854) according to https://en.wikiquote.org/wiki/Louis_Pasteur. Accessed 6/12/25
[2] Busch U. Der erste Strahlenunfall der Geschichte. https://www.drg.de/de-DE/2365/erster-strahlenunfall/ accessed 6/13/25
[3] Walden T. The first radiation accident in America: a centennial account of the x-ray photograph made in 1890. Radiology 181: 1991
[4] Thomas A. The history of radiology. Oxford University Press. 2013. Chapter 1: Wilhelm Röntgen and the discovery.
[5] Roentgen W. . Eine neue Art von Strahlen. 1895. https://archive.org/details/b30475697/page/8/mode/2up?view=theater
[6] Rontgen W. Ueber eine neue Art von Strahlen. Zweite Mitteilung. Ann Phys Chem. N. F. 64. 2: 1, 1896
[7] Theerman P. See-Through Science: The Rise of the X-Ray. https://nyamcenterforhistory.org/2014/11/07/see-through-science-the-rise-of-the-x-ray/ Accessed 6/12/25
[8] Howell – Early clinical use of the X-ray. Transactions Am Clin Climatol Assoc 127: 341, 2016
