When the chemical forces had once reached equilibrium and rest, the earth might then be compared to an immense corpse thrown into space and which must remain in the same state eternally, or until it met with a cosmic catastrophe. Not the slightest movement or variation could now take place spontaneously on its surface. If a change happened it must have had its cause in another source of power, and two such sources existed. One was the earth’s own internal heat, and the other the sun, and we must therefore consider if either of these, or both together could produce combustible organic substance. In regard first to the earth’s internal heat we might immediately eliminate this source of energy, as it has no direct connection whatever with the origin of organic matter, an assertion so commonly agreed upon that we need not dwell further upon it. Infinitely more important is the sun, which has been and is the cause of most of the changes taking place on the earth’s surface after its cooling off. The sun causes the circulation of the air and water and thereby the whole series of disintegration and decay, the history of which is written with indelible letters in our geological sediments and formations. These formations tell us that new oceans and continents, new minerals and rocks have successively been formed, but nowhere that organic substances were ever built up spontaneously under the sun’s influence. The processes of decay, on the contrary, proceed in the entirely opposite direction. Through them nothing is formed but compounds poorer in energy than before. In decaying, the products of combustion absorb, if possible, more oxygen, become more burnt or oxidized, so that this whole process may be called an after-burning, a more thorough combustion of the remnants from the first general world-fire. The spontaneous activity of nature’s forces, then, go in a direction just opposite to the one necessary for the production of organic substances. And anything else was not to be expected. The products of combustion resemble fallen weights, slack bow-strings, water below the fall, etc., whereas combustible organic matter might be compared to lifted weights, set bow-strings, water above the fall, etc. If matter has once fallen from a higher to a lower level of energy it can never spontaneously return, especially as it has just lost the necessary store of energy. As impossible as it is for the swift current to turn its course, or for the fallen weight to lift itself or for the discharged bow-string to set itself again, so impossible is it for the products of combustion spontaneously to turn into combustible substances. CHAPTER VII. Organic Matter as a Product of Art.