X-rays, discovery and history "A new kind of ray".
On November 8 1895, Wilhelm Conrad Röntgen, then Professor of Physics at the University of Würzburg in Germany discovered what he called ‘a new kind of ray’ with remarkable penetrating properties. Generated in a simple evacuated cathode ray tube energized with a high tension discharge, fluorescence was observed on a card coated with barium platinocyanide. The effect persisted despite shielding from the source of the rays with a range of materials, including metals. The ‘penetrating ray’, or ‘X-ray’ as Röntgen termed it, since its origin was mysterious, had been discovered.
Röntgen was a rigorous scientist. Having explained his discovery, when asked by the journalist HJW Dam, ‘What did you think?’ Röntgen is said to have replied ‘I did not think, I investigated’. His investigations included the effect of varying thickness, density, refractive index and chemical composition of the imaged object, using a range of imaging materials including photographic glass plates and film. He tested the effect of various forces on the path of X-rays, including lenses of various materials, and magnetic and electrostatic fields.
Early experiments with biological samples included famous images of the skeletal structure of human hands and a variety of household objects. These images encouraged a variety of medical imaging efforts in many parts of the world, with little or no thought to the potential risks involved. Within several months, Röntgen’s paper had been published in several European languages and experiments had been replicated in England, Japan and America, with early success in imaging ‘bullets, bones and kidney stones’.
By November 1897, the Röntgen Society was formed in England. Within a year a thousand papers were published, and within ten years more than 30 text books had been written on the practical application of Röntgen rays, particularly in diagnostic medicine. The term Röntgen rays was proposed by the anatomist Albert von Kölliker, whose hand Röntgen radiographed at his only public presentation in January, 1896. It was a term which the self-effacing scientist intensely disliked, but is still used in some German speaking countries.
Improvements in the construction of suitable discharge tubes quickly followed. Metal targets and concave cathode plates were used to produce a more focused beam, and a whole new industry was born.
Röntgen was awarded the inaugural Nobel Prize for Physics in 1901 for his discovery.
This is an extract for the XuM Principles and Appllications manual, please email us if you would like a copy of the full document.
