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Over a Century of Mysterious Rays: An Insight Into the X-Ray

Wilhelm Konrad Roentgen


Over a hundred and twenty-five years ago, a German physicist stumbled across a phenomena that was to revolutionize the field of medicine; both in the help of diagnosis, and in a form of treatment. The scientist, Wilhelm Konrad Roentgen ( 1845-1923 ), had discovered X-Rays.

Pioneering nineteenth century scientists had been producing these X-rays for sometime before anybody realised that they were doing so. On the eve of November 8th, 1895, Roentgen was busy working in his laboratory carrying out a routine experiment involving cathode rays.

During the course of this well known experiment he subjected a glass tube containing gas at a very low pressure to a high voltage. The gas, as he had expected, began to glow. However when Roentgen covered this tube with a black cloth, obscuring the glowing gas, he witnessed the small pile of crystals upon his workbench near to the tube continued to glow by themselves.

The curious German realised that some kind of invisible ray must have been coming out of the tube and striking the crystals. In keeping with the general reckless and fool-hardy behaviour associated with early scientists, Roentgen tested the rays with his own bare hands, as his own notes show.

“ I placed my hand before a screen put in the path of the rays, I could see the outline of the bones framed by the flesh. Afterwards, I took a photographic plate, and putting it in the place of the screen, made a photograph of the hands with the bones clearly outlined. “

Roentgen was the first person to actually notice and record the phenomena, despite the fact that many aspiring scientists had been unknowingly producing them for years. The physicist called them X-rays. He chose this particular name because even though Roentgen had discovered them; he could not explain what they were. Hence 'X' stands for 'unknown'.

Not in The Dark.

More than a hundred years on however, we are not so in the dark:- X-rays are a form of radiant energy. They occur naturally in the cosmos, given off by stars, among the myriad of other wavelengths of radiation. They are invisible and thus fall outside the relatively narrow band of luminous rays that we can detect from the Sun. X-rays are short wavelength radiation, occurring throughout a band between gamma rays and ultraviolet radiation.

Although back at the turn of the century fear of these 'unknown' rays was of such a level that tailors in London advertised X-ray proof clothing. They would not have really worked, as tests have since shown that only thick lead will stop X-rays.

Scientists and physicians alike however were quick to realise how useful these new rays would be for looking inside people. There use rapidly spread, and they were soon commonplace, with doctors using them to detect bullets in wounded soldiers, and dentists examining their patients teeth with them.

Industrial Tool.

Industry was also quick to envelope the X-ray, finding numerous applications for the phenomena. Its ability to detect cracks and faults in gas cylinders and other pressure vessels; without the need for expensive destructive testing, was soon utilised.

The development of the aircraft industry opened up another market for the versatile X-ray, being used in the detection of hair-line cracks in aeroplane wings and fuselages.

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Another field that has a wide variety of uses for the X-ray is that of crime detection. Finding many applications ranging use at airports by Customs & Excise personnel to their use by forensic experts examining evidence from the scenes of a major crime.

Great use of X-rays is also made in modern medicine, examining bones, vital organs such as the heart or kidneys. Even the alimentary canal can be photographed by giving the patient a meal containing barium, which shows up on the photographic plate, as this element is opaque to X-rays.

These rays are also used in a technique known as X-ray diffraction. This is a method of studying atomic and molecular structure of crystalline substances by using X-rays. The rays are directed at the crystals, and as they pass through the substance the waves are spread. By measuring the position and intensity of the diffracted waves, it is possible to calculate the size and shape of the atoms in the crystal. This method has been used to study DNA.

Day To Day Usage.

We have highlighted how X-rays are used day-in, day-out, in the diagnosis of illness and injury, and briefly mentioned their role in medical research projects. However in the correct concentration they can also destroy tissue. Thus they can also be used as a treatment, as in the form of radio-therapy. In the treatment of cancer the use of X-rays is invaluable. In some cases, the growth may be completely destroyed, and in many others it is so reduced that removal by an operation is made so much easier. Where inoperable malignant cancers are the issue, then X-rays can be carefully used to enable the patient to live a longer and much more comfortable life than would otherwise be the case.

The X-ray in small, carefully controlled doses is a very useful tool in both medicine and industry. However its usage carries a number of dangers, which may be grouped as 'immediate' and 'remote'.

The former deals with the possibility of making contact with a high-tension lead carrying a very high voltage. This was certainly the case in Victorian and even Edwardian times, but most modern forms of apparatus are reasonably protected against such a contingency, although a high degree of caution is still necessary.

The latter, 'remote' effects are by far the more worrying, as these can arise from over-absorption of the X-rays by the body tissues. These effects do not manifest themselves immediately, sometimes long after the initial exposure. Too great an exposure may lead to warts and cancerous growths. While frequent exposure, even from low dosages, may cause dermatitis which may in turn become the seat of a malignant disease.

Constitutional disorders, anaemia and even sterility are not uncommon among operators who are constantly exposed to X-rays. However recent advances in the methods of application and regular monitoring of staff have diminished the risk of over-exposure.

X-rays are a great benefit to humanity, if handled correctly. Unfortunately this is not always the case, as the incident that filled the media some months back demonstrated. Apparently an incorrectly calibrated X-ray machine subjected thousands of NHS patients to much greater doses than they should have received.

At the beginning of this article I said that nineteenth century scientists had been producing X-rays for quite some time before, thanks to Roentgen, they realised that they were doing so. Wilhelm Roentgen was awarded the Nobel Prize for Physics in 1901, in recognition of his discovery. I wonder what rays our present day scientists are inadvertently producing, and to what uses they will be put, if they are discovered; or on a more sombre note – what new dangers they may be exposing us to.

This content is accurate and true to the best of the author’s knowledge and is not meant to substitute for formal and individualized advice from a qualified professional.

© 2022 David Reynolds

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