What does an X-ray show?

X-rays - are electromagnetic rays of very short wavelength which can penetrate matter through which light rays cannot pass. We call this opaque matter. An X-ray photograph shows a picture of the internal structure of the body allowing doctors to diagnose broken bones to examine the organs of the body. In order to show the position and shape of the stomach and intestine a harmless material such as barium is swallowed, and other opaque substances may be injected to show the outlines of other organs. Oxygen can also be injected into the brain to make its outline sharper. The discovery of X-rays was recorded in January 1896 by Professor Röntgen, Professor of Physics at Würzburg. Chest X-rays led to the early diagnosis of pulmonary tuberculosis and from these beginnings the science of radiography and radiotherapy developed until now countless X-ray installations are in daily use throughout the world. X-rays are used both to diagnose and to treat deep-seated diseases like cancer. Scientific laboratories use them in experiments while industry uses them in work of investigations. By using high-tension apparatus giving up to 300,000 volts, steel can be examined for faults and hidden weaknesses can be discovered in aeroplane construction.