sb. pl. (Also with hyphen.) [tr. Ger. x-strahlen, the name given by Röntgen to the rays in question, expressing the fact that their essential nature is unknown: cf. X 3.] A form of radiation discovered by Prof. W. C. Röntgen of Würzburg in 1895, capable of passing in various degrees through many substances impervious to light, and of affecting a sensitized plate and thus producing shadow-photographs of objects inclosed within opaque receptacles or bodies, e.g., of the bones, or a bullet or other foreign body, within the flesh of a living person or animal; they also produce fluorescence, phosphorescence, and electrical effects, and have a curative operation in certain skin diseases; much used in recent surgical and medical practice. Also called Röntgen rays (see RAY sb.1 1).
1896. Nature, 23 Jan., 274/1. (Röntgen in Sitzungsberichte der Würzburger Phys.-Med. Gesellschaft, 1896, 133 trans. by A. Stanton) A piece of sheet aluminium, 15 mm. thick … allowed the X-rays (as I will call the rays for the sake of brevity) to pass, but greatly reduced the fluorescence.
1897. Allbutt’s Syst. Med., III. 362. Skiagraphs taken by means of the X Röntgen rays. Ibid. (1899), VI. 408. The application of the X rays to the diagnosis of internal aneurisms. Ibid., VIII. 717. The injury produced by the X rays of Röntgen.
b. attrib. and Comb. (in sing. form X-ray).
1897. Westm. Gaz., 2 July, 2/3. Radiations which have the X-ray-like property of passing through so-called opaque substances.
1899. Allbutt’s Syst. Med., VI. 408. Aneurysms of the thoracic aorta can sometimes be detected earlier by X ray examination.
1907. Westm. Gaz., 21 Sept., 8/3. Another X-ray photograph … of a girl’s wrist and hand, showing the thickening of the bone brought on by rheumatism.
1908. Daily Chron., 29 June, 1/5. Dr. Hall Edwards, whose heroic fight against the inroads of X ray dermatitis has been compassionately followed by the King and public.
Hence X-ray v., trans. to examine or treat with X rays. So X-radiation.
1900. Lancet, 17 Feb., 488/2. The patient’s chest had been x-rayed, but the position of the bullet could not be localised.
1902. Brit. Med. Jrnl., 12 April, 894/2. The child was x rayed, and a large nail was seen.
1915. E. Rutherford, in Nature, 9 Sept., 33/2. To examine the quantity and quality of the X-radiation scattered from crystals at different angles.
