What is a sulphide containing one atom of sulphur, and analogous to a monoxide; -- contrasted with a Ant: polysulphide; as, galena is a monosulphide called?

monosulphide — A sulphide containing one atom of sulphur, and analogous to a monoxide; -- contrasted with a Ant: polysulphide; as, galena is a monosulphide. (Webster's 1913.)

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