What is 7. (Chem.) (a) Any earthy-looking metallic oxide, as alumina, glucina, zirconia, yttria, and thoria. (b) A similar oxide, having a slight alkaline reaction, as lime, magnesia, strontia, baryta called?

earth — 7. (Chem.) (a) Any earthy-looking metallic oxide, as alumina, glucina, zirconia, yttria, and thoria. (b) A similar oxide, having a slight alkaline reaction, as lime, magnesia, strontia, baryta. (Webster's 1913.)

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