The two tubes were then examined separately in detail. No. 2, excited by the magnet, showed curious effects. The glow was rendered weak and intermittent, and the rosy tint almost disappeared. The capillary changed to a decided green colour, and the positive electrode was surrounded by a yellow glow. The changes in the spectrum were no less decided. Without the magnet, the spectrum was found to be a bright continuous one of H (with a full set of principal and intermediate lines) and N—the N spectrum being rather faint and misty, with very slight, if any, traces of the iodine-spectrum. On the magnet being excited, the spectrum changed as if by magic; the H and N spectra disappeared (except hydrogen F, which still faintly remained), and the iodine lines, mostly in the yellow-green and green, shone out wonderfully sharp and bright on quite a dark ground. No. 1, upon examination, showed between the magnet-poles only the same changes as on last occasion. The spectrum seemed to be one of iodine, with the addition of slight traces of the H spectrum. [Sidenote: Effects discussed.] On excitation of the magnet, the misty continuous part of the spectrum nearly disappeared, and the bright lines shone up sharply upon the dark background as before. The effects in the case of both tubes were strongly marked. The impression as to tube No. 2 was that, without the magnet, the slight iodine-spectrum was overpowered and masked by the N and H spectra; while under the influence of the magnet the N and H spectra were almost altogether suppressed, the iodine-spectrum being at the same time intensified. The disappearance of the continuous spectrum under the action of the magnet in No. 1 (with the supposition it was mainly H) would be accounted for in the same way. _Bromine-tubes._ [Sidenote: Bromine-tube No. 1. Lighting-up described. Effect of the magnet. Bromine-tube No. 2. Effect of magnet.]