826. Sulphur is yellow, because it is the earthy that has come to light, the carbon is black, because it is sulphur volatilized, moistened in the gloom or darkness of the earth. D.--_SALTS_. _Salt-periods._ 827. So long as the basis of the acid is an earthy, such as carbon or sulphur in the carbonic and sulphuric acids, does the earthy also obtain the preponderance, and the lime as well as the gypsum or sulphate of lime are precipitated as insoluble bodies. 828. It is only through the influence of light constantly becoming more powerful by reason of the solid land under the water that the oxydation of water rises to the highest degree, so that this element finally converts itself into an acid, or hydro-oxide. This process must be regarded as a decomposition of water, whereby a portion of the hydrogen forms sulphur with the carbon, the rest with the oxygen an hydro-oxide. 829. The hydro-oxide is hydrochloric acid. This acid must be regarded as peroxydized hydrogen. Its signification is thus that of being water itself, or a whole element with a preponderance of oxygen. It attains this rank by its constituent parts, namely, the two general gaseous primary bodies, by its distribution as a whole element around the earth; by its occurrence as an earth-formation in rock-salt; finally, by its presence in all vegetable and animal juices. Hydrochloric acid is the type of all acids, as the iron is of all metals. All acids are but imitations of the hydrochloric. All abide by the signification of water, or are conversions of elements or earths by oxydation into an hydroid condition. 830. Between the acidified water and the Earthy a higher antagonism now emerges. The Earthy separates a part of its carbon from the carbonic acid and sulphur, so that the rest remains behind peroxydized, and makes its appearance as an alkali. 831. The alkali is to be regarded as the last conversion of calcareous earth in respect to water. It is an earth, whose oxygen has converted itself with a portion of its carbon into acid and been set free; a salt halved upon the basic side. This general alkali, that has originated in water, is _soda_ or natrom. 832. Alkali and acid are the last antagonism in the earthy, moieties, which can never subsist without each other. 833. The alkali is corrosive, because it seeks water and acid, in order to perfect itself; acid is pungent to the taste, because it seeks earth or alkali. 834. Their antagonism is the highest antagonism between water and earth; it is also the representation of the antagonism between fire and the terrestrial elements, or also between light and gravity. Therefore this antagonism has a cosmic or universal signification. 835. The combination of this antagonism is the _sea_-or _common salt_. 836. Sea-salt is the universal salt. All other salts are to be regarded only as metamorphoses of it, as well as the acids only conversions of the acid of common salt, and the alkalies of soda.