Now we have seen that the Sun is the source of all light and heat; the source--when the element is concentrated--of that which we denominate _fire_. The phenomena that fire pervades, by some of its constituents, every thing, and all space, is incomprehensible otherwise than in the belief that the Spirit of God is everywhere. Although fire is always on this Earth in a concentrated form, yet its source is the Sun, and from this source we can concentrate it into visible ignition. And yet we see that the element itself is _ethereal_; it will consume by combustion, yet its heat and flame always tends upward, and disappears in its own ethereal element, and we can recognize no solid substance in it. We can feel and realize its warmth and vivifying influence; we enjoy the light, as one of its productions, yet all are _ethereal_, and we cannot grasp, mould, or retain it. We know that the Sun--that volume of heat--is the active source and agency of life and animation, and it imparts its blessings to us in a thousand ways; yet, misused, it proves the source and element of punishment and destruction. We have said that light and heat are the two great stimulants of vital force. These two stimulants are inseparably connected. Heat is the source of light, and without heat _there would be no light_, for even reflected light is derived from this source; this is manifest to every intelligent mind. Therefore, we see plainly that the Sun is the source and mainspring of all animation, and to its influence, directed and controlled by the Allwise Creator, are we indebted for every blessing--nay, even life itself. It acts upon the elements appointed unto it, and brings forth all animation. It causes the earth to yield her productions; clothes the forest with green, gives to the "rose" and the "lily" their beautiful tints and fragrance, and imparts to the flowers of garden and forest their thousand variegated hues. It gives to man his strength and wisdom, and to woman her beauty and loveliness, and--with refined and cultivated intellect--her ten thousand charms. _THE PLANETS OF OUR SOLAR SYSTEM._ Let us now turn our attention, for a short time, to the contemplation of the planets, or worlds, belonging to our own solar system; those within the domain of our own Sun, and to which it dispenses light and heat. With these, our Astronomers are, so to speak, quite familiar. We cannot do better than to present them to you in the language of Dr. Child, whose writings have afforded us so much correct data in preceding pages.