X-rays.- Röntgen (Wilhelm Conrad) "Ueber eine neue art von strahlen" [parts 1 & 2] [and] "Weitere beobachtungen uber eigenschaften der x-strahlen", in Annalen der Physik und Chemie, 1898, vol. 64, no.1 pp.1-37, illustrations, modern cloth with gilt-lettered morocco label to upper cover, Leipzig, 1898; and another including a paper by Röntgen and Exner titled "Uber eine Anwendung des Eiscalorimeters zur Besttimmung der intensität der Sonnenstrahlung", 8vo (2)*** The first collected edition of Röntgen's highly important 3 papers on the discovery of X-rays, for which he was awarded the Nobel Prize for Physics in 1901.