First edition of the two papers in which Röntgen announced his discovery of ‘A New Kind of Ray’. The offprint of the first part was dated "Ende 1895” on the wrapper, and this went through four more printings in 1896. Röntgen sent copies of the offprint, together with X-ray photographs, to a number of prominent scientists, and the news of his discovery quickly spred around the world. A third and final report appeared in the Sitzungsberichte der Königlichen Preussischen Akademie der Wissenschaften zu Berlin in 1897. These three short papers represent one of the most important advances in the history of scientific development. For his discovery, Röntgen was awarded the first Nobel Prize for Physics in 1901. "It was while experimenting with forms of the Geissler tube devised by Philipp Lenard and William Crookes that Röntgen, at the time professor at Würzburg University, noticed that a paper screen coated with barium platinocyanid lying on a table had become fluorescent. He traced the cause of this phenomenon to the tube, despite the fact that it was enclosed in a light-tight black cardboard box. Röntgen expounded in these two papers – "A New Kind of Ray’ – his experiments with the comparative penetrative powers of this form of radiation. He found that although human flesh is translucent to it, bone is opaque, and photographic plates are affected by it. Indeed at the second of the two sittings in which he announced his discovery he persuaded a member of his audience, his colleague, Professor Albert von Kölliker, the famous anatomist, to permit the photographing of his hand by X-rays. ... Their importance in surgery, medicine and metallurgy is well known. Incomparably the most important aspect of Röntgen’s experiments, however, is his discovery of matter in a new form, which has completely revolutionized the study of chemistry and physics. Laue and Braggs have used the X-rays to show us the atomic structure of crystals. Mosely has reconstructed the periodic table of the elements. Becquerel was directly inspired by Röntgen’s results to the investigation that discovered radio-activity. Finally J. J. Thomson enunciated the electron theory as a result of investigating the nature of X-rays” (PMM). Collation: Complete volume 1894-1896: pp iv, 157, (1); pp iv, 151, (1); pp iv,173, (1). Röntgen’s articles: 1895:9: pp 132-141; 1896:1: pp 11-16 with one full-page halftone illustration of "Hand des Anatomen Geheimrath von Kölliker”; 1896:2: pp -19. (The offprint issue of the second paper does not have the picture of Kölliker’s hand!) Binding: Bound in two volumes. Ochre boards, black lined spine with black lettering. References: Garrison-Morton 2683; Horblit, One Hundred Books Famous in Science 90; Grolier, One Hundred Books Famous in Medicine 83; Printing and the Mind of Man 380; Norman 1841-42; Dibner, Heralds of Science 162; Lilly Library, Notable Medical Books 239; Heirs of Hippocrates 2090; Friedman & Friedland, Medicine’s 10 Greatest Discoveries, pp 115-32. Waller 8078 & 8083 (1st and 2nd papers).