When planning a historically-orientated introduction to a book on X-rays it becomes clear at an early stage that there is no shortage of material, so well documented are the facts relating to the discovery and early investigation of X-radiation. Many of the facts are well-known, but the very richness of the subject presents interesting opportunities for discussion, not only because of the large amount of material published during the twelve months or so following the discovery (it has been stated that almost 1000 communications were published during that one year), but also because of the great increase in X-ray studies in recent years, which naturally stimulates an interest in the origins and early days of the subject.

The discovery of X-rays, which took place on 8 November 1895 in Würzburg, Bavaria, constituted an event the importance of which was immediately obvious to the discoverer, and which became apparent to the world at large within a very few weeks of Röntgen's announcement. The subject of X-rays has, of course, always enjoyed the twin privilege of being important as a branch of physics in its own right and of having applications in medical practice the importance of which is known to all. Therein lies a clue to the great speed with which the early researches were put in hand.

Röntgen reported his discovery on 28 December, and dispatched some X-ray photographs and a few copies of his paper to friends on New Year's Day, 1896.