Of all forms of paganism, that of the Fire Worshipers[5] seems least unreasonable, for the sun is even now, to us, the best symbol of beneficence and unfailing energy. After thousands of years it shows no diminution of power, and although the imagination can conceive the possibility of its destruction, the most accurate scientific observations have not discovered the slightest indications of its lessening influence. “His going forth is from the end of the heaven, and his circuit unto the ends of it; there is nothing hid from the heat thereof.” CHEMICAL ACTION. In a preceding article the chemistry of fire has been considered at some length. It only remains to mention briefly a few of the physical phenomena attending it. When elements unite by the force of affinity, it is supposed that their atoms rush together, and that their motion is converted into heat. In the case of the galvanic battery the impetuous movement of the atoms toward the poles becomes electricity. We have constantly recurring instances in nature of that great truth that energy, though constantly disappearing is never lost, but reappears under new manifestations and a new name. It may for a time remain dormant, and anon become perceptible, as in the case of latent heat. For example, in mixing five pounds of water at a temperature of 212° Fahrenheit, and five pounds of ice, seven hundred and fifteen units of heat disappear in melting the ice, and the aggregate temperature of the mass is proportionally lower than that of the substances united. But upon their returning to their former state, this latent heat reappears as sensible heat. In chemical action producing fire, the uniting materials are usually converted, first, into a gaseous form, but there are some exceptions. The most interesting is the following: When a few flakes of iodine are placed upon a fragment of phosphorus, the atoms of the two elements rush together with great energy, producing spontaneous combustion, and liberating sufficient heat to burn the superfluous iodine, with the evolution of beautiful violet fumes. The mechanical action in flame is full of interest. Its brightness always seems to depend upon the incandescence of solid particles. This can easily be seen in an ordinary lamp. A piece of cold porcelain inserted in a flame will cool the incandescent carbon, and it will be deposited as soot. The Bunsen[6] burner clearly proves that the brilliancy of our lights depends upon the incandescence of the carbon. This is a contrivance for passing jets of air through a flame, so that the intimate mixing of the oxygen of the air with the carbon will cause the immediate combustion of the latter. This results in converting it instantly to invisible gas (CO₂) before incandescence, and consequently the Bunsen flame, while it is intensely hot, emits but a feeble light. Any _physical_ change that facilitates the movement of atoms seems to increase the intensity of chemical action.