The spectrum of the new star as examined by M. Cornu, of the Paris Observatory, showed the bright lines of hydrogen, indicating the presence of enormous quantities of glowing hydrogen, in a state of intense heat. But beside these bright lines, others also could be seen. One of these was an orange-yellow line. It will be understood that the faint spectrum of a star cannot be so readily lengthened by increasing the dispersion as a bright spectrum; for with too great dispersion the light fades out altogether. And though this is not strictly the case with the bright lines, which are merely thrown farther apart by dispersion, yet still it remains true that one cannot deal with a star spectrum even of bright lines as one can with the solar spectrum. So that M. Cornu was not able to determine whether the orange-yellow line belonged to sodium, or to that other substance, whatever it may be, which produces the orange-yellow line seen in the spectrum of a solar prominence.[9] Another bright line, green in colour, agreed in position with a triple line belonging to the metal magnesium. Lastly, a bright yellowish-green line was seen, which is known to be present in the spectrum of the sun's corona and of the low-lying ruddy matter round the sun, called the _sierra_ by some, and by others (apparently unfamiliar with the Greek language) the chromosphere. Now all this agrees very well with what had been noticed in the case of the star in the Northern Crown. For, unquestionably, if a sun increases so much in heat and lustre that the hydrogen outside it glows more brightly than the body of the star, then other matter _outside_ that sun might also be expected to share the great increase of heat. We see that, outside our own sun, hydrogen, a certain unknown vapour of an orange yellow colour, magnesium, and another unknown vapour of greenish-yellow colour are present in enormous quantities; and it seems, therefore, reasonable to believe that other suns have these gases extending far outside the rest of their substance. It is certain that, if our sun were caused to glow with far more than its present degree of heat, the gases whose increase of brightness would be most discernible from a distant station (as a world circling around some remote star) would be just those gases which were glowing so resplendency around the star in Cygnus last November--or rather at the time when that light which reached us last November set out from the remote star in the Swan.