Further, some stars exhibit changes of complexion in themselves. Sirius, as before stated, was once a ruddy, or rather a fiery-faced orb, but has now forgotten to blush, and looks down upon us with a pure, brilliant smile, in which there is no trace either of anger or of shame. On the countenances of others, still more varied traits have rippled, within a much briefer period of time. May not these be due to some physiological revolutions, general or convulsive, which are in progress in the particular orb, and which, by affecting the constitution of its atmosphere, compel the absorption or promote the transmission of particular rays? The supposition appears by no means improbable, especially if we call to mind the hydrogen volcanoes which have been discovered on the photosphere of the sun. Indeed, there are a few small stars which afford a spectrum of bright lines instead of dark ones, and this we know denotes a gaseous or vaporized state of things, from which it may be inferred that such orbs are in a different condition from most of their relations. And as, if for the very purpose of throwing light upon this interesting question, an event of the most striking character occurred in the heavens, almost as soon as the spectroscopists were prepared to interpret it correctly. On the 12th of May, 1866, a great conflagration, infinitely larger than that of London or Moscow, was announced. To use the expression of a distinguished astronomer, a world was found to be on fire! A star, which till then had shone weakly and unobtrusively in the _corona borealis_, suddenly blazed up into a luminary of the second magnitude. In the course of three days from its discovery in this new character, by Birmingham, at Tuam, it had declined to the third or fourth order of brilliancy. In twelve days, dating from its first apparition in the Irish heavens, it had sunk to the eighth rank, and it went on waning until the 26th of June, when it ceased to be discernible except through the medium of the telescope. This was a remarkable, though certainly not an unprecedented proceeding on the part of a star; but one singular circumstance in its behavior was that, after the lapse of nearly two months, it began to blaze up again, though not with equal ardor, and after maintaining its glow for a few weeks, and passing through sundry phases of color, it gradually paled its fires, and returned to its former insignificance. How many years had elapsed since this awful conflagration actually took place, it would be presumptuous to guess; but it must be remembered that news from the heavens, though carried by the fleetest of messengers, light, reaches us long after the event has transpired, and that the same celestial carrier is still dropping the tidings at each station it reaches in space, until it sinks exhausted by the length of its flight.