We find, when we receive solar spectra upon iodized plates, or on several kinds of photographic paper, that a line, over which no action takes place, is preserved at the top and bottom of the impressed image, and in many cases along the sides also. The only way in which this can be accounted for, as the spectrum represents the sun in a distorted form, is by supposing that rays come from the edges of the sun of a different character from those which proceed from the centre of that orb.[129] Light from the centre of the solar disc is under different conditions from that which comes from the edge of the sun: this is due to the varying angle, which is presented to us by a circular body: calorific action seems to be more strongly manifested when the envelope of light, extending like an atmosphere to the sun, is thrown into great agitation, and waves, and great hollows--solar spots--are produced. There is some indication of the existence of a third condition on the sun’s surface, to which probably belongs the mighty chemical power which we call actinism. Electricity may be, as some have speculated, the exciting agent; a constant and violent Aurora Borealis may exist on the sun, and under the excitation of this force the others named may be quickened into full activity. That actinism is one of the great powers of creation we have abundant proof. Nearly all the phenomena of chemical change which have been referred to light, are now proved to be dependent upon actinic power; and beyond the influence which has been ascertained to be exerted by it upon all inorganic bodies, we shall have occasion to show still further the dependence of the vegetable and animal worlds upon its agency. The influence of the solar beams on vegetation is proved by common experience; the closer examination of its action on vegetable life is reserved for the chapter devoted to its phenomena. Of its influence on animals nothing is very correctly known; but some early experiments prove that they, like other organised bodies, are subject to all the radiant forces, as indeed, independent of experiment, every observation must teach. Certain it is, that organisation can take place only where the sun’s rays can penetrate: where there is unchanging darkness, there we find all the silence of death. Prometheus stole fire from heaven, and gave the sacred gift to man, as the most useful to him of all things in his necessities: by the aid of it he could temper the severities of climate, render his food more digestible and agreeable, and illuminate the hours of darkness. So says the beautiful fiction of the Grecian mind,--which appears as the poetic dream or prophetic glance of a gifted race, who felt the mysterious truth they were yet unable to describe. Pheaton and Apollo are only other foreshadowings of the creative energies which dwell in the glorious centre of our universe. The poetry of the Hellenic people ascended