Exclusively, therefore, for the purposes of _illustration_, I would take as an instance of the first step, the metals, those, namely, that are capable of permanent reduction. For, by the established laws of nomenclature, the others (as sodium, potassium, calcium, silicium, &c.) would be entitled to a class of their own, under the name of _bases_. It is long since the chemists have despaired of decomposing this class of bodies. They still remain, one and all, as elements or simple bodies, though, on the principles of the corpuscularian philosophy, nothing can be more improbable than that they really are such; and no reason has or can be assigned on the grounds of that system, why, in no one instance, the contrary has not been proved. But this is at once explained, if we assume them as the simplest form of unity, namely, the unity of powers and properties. For these, it is evident, may be endlessly modified, but can never be decomposed. If I were asked by a philosopher who had previously extended the attribute of Life to the _Byssus speciosa_, and even to the crustaceous matter, or outward bones of a lobster, &c., whether the ingot of gold expressed _life_, I should answer without hesitation, as the _ingot_ of gold assuredly not, for its form is accidental and _ab extra_. It may be added to or detracted from without in the least affecting the nature, state, or properties in the specific matter of which the ingot consists. But as _gold_, as that special union of absolute and of relative gravity, ductility, and hardness, which, wherever they are found, constitute _gold_, I should answer no less fearlessly, in the affirmative. But I should further add, that of the two counteracting tendencies of nature, namely, that of _detachment_ from the universal life, which universality is represented to us by gravitation, and that of _attachment_ or reduction into it, this and the other noble metals represented the units in which the latter tendency, namely, that of identity with the life of nature, subsisted in the greatest overbalance over the former. It is the form of unity with the least degree of tendency to individuation. Rising in the ascent, I should take, as illustrative of the second step, the various forms of crystals as a union, not of powers only, but of parts, and as the simplest forms of composition in the next narrowest sphere of affinity. Here the form, or apparent _quantity_, is manifestly the result of the _quality_, and the chemist himself not seldom admits them as infallible characters of the substances united in the whole of a given crystal. In the first step, we had Life, as the mere _unity_ of powers; in the second we have the simplest forms of _totality_ evolved. The third step is presented to us in those vast formations, the tracing of which generically would form the science of Geology, or its history in the strict sense of the word, even as their description and diagnostics constitute its preliminaries.