Assimilation is only possible by dissolving. For the purpose of assimilation, air and water dissolved the earth's crust; by the agency of those powers that surface originated which produces and nourishes all organic bodies. As these exist in the same world in which the elements continually exercise their power of dissolving and assimilating, it follows, that from the beginning there must have been developed in all organic elements the same power, as a protection to themselves. Air dissolves water into vapours, in order to assimilate gases from it. Water extracts from air the oxygen gas. Fire absorbs the oxygen of air, dissolves water into its two component parts, hydrogen and oxygen, and by converting the former to a flame, transforms water to fire; air absorbs many gases which fire releases from combustibles; air draws gases from the soil, the soil absorbs the oxygen of the air. In this way the elements are in a constant conflict, each endeavouring to dissolve the other, and to assimilate its matters with itself. Organic bodies draw oxygen from the air by the process of respiration, which is also the property of plants: these draw all assimilatory matter which the earth offers by their roots. The same process is performed by animals feeding on plants or herbs; whereas, on the contrary, fire resolves all organic matter into its original elements. This same process is carried out by water and air, with all organic beings, but as long as these are living they only get their evaporation, and after death their entirety. The earth exercises this power but conditionally and partially, viz. upon all animals that exist in it, and on all roots of plants; upon mankind the earth only exercises its power of assimilation after death. The proofs of this conflict of assimilation in organic matter itself are clear, one animal eats the other as well as plants; that is to say, it absorbs by the agency of the stomach so much of their substance as may be assimilated. Plants again convert parts of dead bodies and other plants (the manure) into their own substance. Besides this power of assimilation, there exists in every being, element and organisation, the necessity of being exposed to foreign assimilation. This is the fundamental principle of the true doctrine of healing. In support of this theory, we find that water, if withdrawn from the power of dissolution by the fresh air, stinks and putrefies. Air loses its oxygen and becomes mephitic, if it does not find water or plants with which it can enter into the conflict of dissolution and assimilation.