mentioned above, the increase in glow was apparent on the two faces of the sheet. Given that there is no rise in temperature, this seems paradoxical; for since "N" rays do not go through platinum, it seemed as if the action should only appear on the side exposed to these rays. To reconcile these results, it was necessary to suppose that "N" rays, which do not traverse cold platinum, traverse it when incandescent. I then reverted to the apparatus which was destined to show the action of "N" rays on a small flame, and behind the quartz lens I arranged a platinum sheet larger than the lens. The interposition of a lead screen between the platinum and the source produced no effect on the small flame, which verifies the opacity of platinum. The plate being then heated to redness, interposing the screen was seen to diminish the glow of the small flame. "N" rays issuing from an Auer burner traverse therefore incandescent platinum.
