871. As the principle or rationale of chemical action consists only in the potentiality of two elements to revert to their polar, or the oxygenous, condition, this action must thus become extinct, so soon as the creation of the new or secondary element has resulted. For if the tension equalizes itself in the two, and the two only be coexistent, so in accordance with the compensation no new tension can originate, and yet such is the groundwork of all chemical action. The result of the chemical process is consequently death; and furthermore, because it is also a simple bin-elementary process, it cannot be the ultimate goal or limit attained by the development of the planet. 872. The next stage to which the genesis of the planet ascends consists in the bin-elementary processes being associated with the _third_ terrestrial element. In this manner a process originates in which the powers of _earth_ and of _water_ marry or conjoin with the power of _air_, and thus originates a chemical power or chemism, influenced by the air. 873. The chemism, when influenced by air, is one of a perpetual character; for this power dies only because the tension of its two elements is balanced or equalized; the influence of the air is, however, none other than the constant renewal of the tension. 874. Now, the process of tension in the air is electrism or that action in which the two poles being devoid of indifference range opposite to each other, can therefore never unite, and the end attained by which is oxydation. The new process is consequently a chemical power constantly excited by electrism--it is an _electro-chemism_. (Ed. 1st, 1810.) This composite process is known under the name of _Galvanism_. 875. Hereby the galvanism has been most rigorously and characteristically separated from the chemism, and the succession of stages been exactly indicated. By the accession of a single but higher nature-factor, namely, the air, chemism advances one and _only_ one stage higher. We have consequently made no leap or abrupt transition in tracing out our genesis of nature. Magnetism is the uni-elementary, chemism the bin-elementary, galvanism the tri-elementary process of the _planet_, in so far as it is occupied with its own evolution, or that of the _Solid_. 876. Considered in relation to the result and also the internal nature of the process, galvanism is in no wise different from chemism, but only in reference to the continuance of the tension. The fluid and solid are in both the co-equal media or means; the decompositions, separations and combinations also, are alike in both. The air has no other office than to sustain the opposition, which in chemism proceeds through the difference of the two unipolar elements, acid and alkali.