The X-Rays ~
When the cathode rays --- that is to say, the electrons emitted by a Crookes’ tube or by a radioactive body, meet an obstacle, they give birth to special radiations called x-rays when they come from a Crookes’ tube, and gamma rays when emitted by a radioactive body. These radiations travel in a straight line, and can pass through dense obstacles. They are not reflected, refracted, nor polarized, and this absolutely differentiates them from light. They are not deviated by a magnet, and this separates them sharply from the cathode rays, whose power of penetration is, besides, infinitely more feeble. The x- or gamma-rays possess the property of rendering air a conductor of electricity, and consequently of dissipating electric charges. They render phosphorescent various substances, and impress photographic plates.
...Now, the x-rays, supposed to be so near to this extreme region of the ultraviolet, pass, on the contrary, through all obstacles, thick metal plates included. If they did not possess fluorescence and photographic action, no one would have dreamed of comparing them to ultraviolet light
...The impossibility of giving to the x-rays that deviation by a magnetic field which the cathode rays undergo, has caused them to be looked upon as no longer possessing any electricity, but this conclusion may easily be contested. Suppose, in fact, that the x-rays are constituted of electric atoms still more minute than the ordinary negative electrons, and that their speed of propagation borders on that of light. According to the researches to be presently mentioned, electrons having such a velocity would have an infinite mass. Their resistance to motion being infinite, it is evident that they could not be deviated by a magnetic field, though composed of electric elements.
What now seems to be most evident is that there is no more reason to connect the x-rays with electricity than with light. Assimilations such as these are the offspring of that habit of mind which induces us to connect new things with those previously known. The x-rays simply represent one of the manifestations of intra-atomic energy liberated by the dissociation of matter. They constitute one of the stages of the vanishing of matter, a form of energy having its own characteristics, which must be defined solely by these characteristics without endeavoring to fit it into previously arranged categories. The universe is full of unknown forces which, like the x-rays of today, and the electricity of a century ago, were discovered only when we possessed reagents capable of revealing them. Had phosphorescent bodies and photographic plates been unknown, the existence of x-rays could not have been verified. Physicists handled Crookes’ tubes, which yield these rays in abundance, for a quarter of a century without discovering them.
If it is probable that the x-rays have their seat in the ether, it seems certain that they are not constituted by vibrations similar to those of light. To me, they represent the extreme limit of material things, one of the last stages of the vanishing of matter before its return to the ether.
...Finally, we come to the gamma radiations, which are no longer stayed by any obstacle, which no magnetic attraction can deviate, and which seem to constitute one of the last phases of the dissociation of matter before its final return to the ether.
...If the earth were not protected from the extreme solar ultraviolet rays by its atmosphere, life on its surface, under existing circumstances, probably would be impossible.
Solar light does not possess the property of dissociating the molecules of gases. These can only be dissociated by the absolutely extreme ultraviolet radiations. If, as is probable, these radiations exist in the solar spectrum, before their absorption by the atmospheric envelope, an energetic dissociation of the aerial gases must take place on the confines of our air. This cause must have contributed, in the course of ages, to deprive certain stars, like the moon, of their atmosphere.
~~Gustave Le Bon