Emily Dickinson Lexicon

OCULUS-MUNDI, n. [Oculus mundi.]

Otherwise called hydrophane and lapis mutabilis, a precious stone of an opake whitish brown color, but becoming transparent by infusion in an aqueous fluid, and resuming its opacity when dry. It is found in beds over the opals in Hungary, Silesia and Saxony, and over the chalcedonies and agates in Iceland. Encyc.