Calx aerata is not ſoluble in water without an exceſs of the ſubtil acid, and therefore might properly be referred to the earths (§ 21).
MAGNESIA vitriolata (Epſom ſalt) is not unfrequent in the waters of England, Bohemia, and other countries. This ſalt is preſently decompoſed by lime water, which circumſtance readily diſtinguiſhes it from the alk. min. vitriol. or Glauber’s ſalt.
MAGNESIA nitrata (magneſia and nitrous acid) is uſually found together with nitre.
MAGNESIA ſalita (magneſia and muriatic acid) is found diſſolved in various waters, but plentifully in ſea water, to which it gives a diſagreeable bitterneſs.
MAGNESIA aerata (common magneſia) with an exceſs of aerial acid it becomes ſoluble in cold water, otherwiſe it is ſcarce ſoluble at all, and therefore ſhould be claſſed with the earths. (§ 21.)