Of the Marine Acid.
The marine acid is procured from common salt by the vitriolic acid, which unites with its base, the fossil alkali.
This acid is generally of a straw-colour; but this is owing to an impregnation with some earthy matter, most of which it readily dissolves, especially the metallic ones. It is less capable of concentration than the vitriolic or nitrous acids, perhaps from a more intimate union of phlogiston with it. No heat can extract from it any dephlogisticated air.
Though this is denominated a weaker acid than the nitrous, yet it will take silver, lead, or mercury, from their union with the nitrous acid. Upon this principle, a solution of these metals in the nitrous acid will readily discover whether any water contains the marine acid, the latter uniting with the metal dissolved in the former, and forming with it, if it be silver, a luna cornea; which being a substance insoluble in water, discovers itself by a cloudy appearance.
The union of the marine acid with earths forms salts that easily deliquesce, but with the metals such as are capable of crystallization; and so also is that formed by the union of this acid to terra ponderosa.
Neither this acid nor the nitrous will dissolve gold or platina; but a mixture of them, called aqua regia, will do it.
The marine acid has a strong affinity to dephlogisticated air, and will take it from manganese and other substances; and with this union it becomes a different acid, called dephlogisticated marine acid, being water impregnated with dephlogisticated marine acid air, described above.