Roentgen's strange order. A contribution to the history of the discovery of Roentgen rays

Due to the fact that Roentgen never reported the details of the discovery of his 'new rays', he left the door open for speculative interpretations. As a contribution to a serious analysis of the history of Roentgen's discovery, this paper presents a previously unnoticed letter relating to an order of a number of very thin crystalline absorbers. The addressee is unfortunately unknown. The letter is dated November 15, 1895. Therefore, this letter must be considered to be the first well documented remark made by Roentgen after seeing the earliest indications of the new rays only one week earlier. The order seems to emphasize the role of a particular type of cathode ray tube developed by Philipp Lenard, Nobel Prize winner of 1905, and manufactured by the glassblower Louis Mueller-Unkel in the discovery of the new radiation. It partly contradicts an analysis based on Roentgen's order book from Wuerzburg made by the author et al. some years ago. Completed by the document presented here, Roentgen's order correspondence allows some insight into Roentgen's intentions during this productive period. The autograph was found at Staatsbibliothek Berlin, Sammlung Darmstaedter, by the author. (orig.)