"N" Rays/Preliminary Notice
The present volume contains the memoirs on the subject of "N" rays, communicated to the Academy of Sciences by Prof. R. Blondlot. The papers have been reprinted exactly as they were originally published in the Comptes Rendus of the Academy. The notes at the end were added later, with the object of throwing light on certain points which were obscure at the time the papers were communicated to the Academy.
The title of the first memoir in this collection, "On the Polarization of 'X' Rays," will hardly cause astonishment when it is realized that the study of the "X" rays led the author to recognize the existence of radiations of a totally different character. To these he gave the name of "N" rays. Before the distinction of these two kinds of radiation was made, some confusion was bound to arise between the phenomena appertaining to each. In particular, the preliminary researches which the author had made on the velocity of propagation of "X" rays apply in reality not to "X" rays, but to "N" rays. He had found that the velocity of propagation was the same as that of Hertzian waves, and consequently of light. Since the properties of "N" rays, taken in their entirety, do not leave any doubt that these rays are a variety of light, this determination of their velocity is nothing more than a verification of an assured fact. Nevertheless, this verification seemed not altogether superfluous; it proves at least that the experiments have been carried out with care.
- Comptes Rendus, t. cxxv. pp. 666, 721, 763.