applied to the sidereal heavens a star of such marvellous character should have presented itself.... The feature which made the spectrum of the new star essentially distinct from that of any other star that had been previously observed was the presence of certain bright lines superposed on a spectrum with dark lines of one of the ordinary types. The position of certain of these lines showed that one of the luminous gases must be hydrogen.... The spectroscope showed that there must have been something which we may describe as a conflagration of hydrogen on a stupendous scale, and this outburst would account for the sudden increase in luminosity of the star, and also to some extent explain how so stupendous an illumination, once kindled, could dwindle away in so short a time as a few days." It will be seen that these new stars leap suddenly into great brilliancy: it is a matter of a few hours only. After remaining a very short time in this stage of abnormal incandescence, they gradually die out again in lustre and revert to their original condition; they are not consumed either in body or atmosphere. Several theories have been advanced to account for these remarkable phenomena; see "Suns in Flames," by Professor Proctor. One is, in effect, that by some sudden "internal convulsion a large volume of hydrogen and other gases was evolved from it, the hydrogen by its combination with some other element giving out the lines represented by the bright lines, and at the same time heating to a point of vivid incandescence the solid matter of the star's surface.... As the liberated hydrogen gas became exhausted the flame gradually abated, and with the consequent cooling the star's surface became less vivid and the star returned to its original condition;" which, by the way, it never could have done if its atmosphere had been exposed to such a disintegration, without the construction of an entirely new atmosphere precisely similar to the one just destroyed. The process would be one of simple combustion. It requires the evolution of enormous volumes of hydrogen from within the planet, and of other enormous volumes of something else, by which to burn it up and yet not burn up the original hydrogen envelope. This other element could not have previously existed outside the solar body and contiguous thereto, or it would have burned up the ordinary hydrogen envelope of the sun long before, as well as the metallic vapors floating therein. Both these mutually hostile gases must have come from within, and this is manifestly impossible, as we should thus have explosion and solar destruction, but not combustion. There is no reason to believe that hydrogen, the lightest of elements, could have remained occluded within the solar mass, to the exclusion of the heavier metals, if disassociated, and if held combined no such sudden liberation could occur. Besides, such convulsion would be impossible in any sun at all resembling ours,