Page:"N" Rays (Garcin).djvu/101

Rh same curve, within the limits of experimental error. The study of radiations still less refrangible than those I have dwelt on appeared to me impracticable. To avoid confusion, I was obliged to adopt a very large scale for the ordinates; this is why I could not plot on the diagram the results of my former measurements of the more refrangible "N" rays (loc. cit.). These results give points situated on a branch of the curve, starting from the topmost point on the right, and rising almost vertically, with a feeble inclination, from bottom to top, and from right to left, and a slight convexity turned upwards.

Certain sources seem to emit N$1$ rays exclusively, or, at least, these rays predominate in the emission. This is the case with copper and silver wire, and with hard-drawn platinum wire. M. Bichat has observed that ethylic ether, when brought to the state of forced extension, by the process discovered by M. Berthelot, emits N$1$ rays. When this state of strain ceases, whether spontaneously or under the action of a slight blow, the emission of N$1$ rays immediately disappears.