COBALTOUS a.
esp. of cobalt compounds in which the metal has its lower valence. Cobaltous chloride, a crystalline compound, CoCl2, of a pale rose color when hydrous, blue when dehydrated. Its solution is used for a sympathetic ink, the writing being nearly colorless when dried in the air, owing to absorbed moisture, and becoming b…
COMPOUND a.
n, division (Arith.), the addition, substraction, etc., of compound numbers. -- Compound crystal (Crystallog.), a twin crystal, or one seeming to be made up of two or more crystals combined according to regular laws of composition. -- Compound engine (Mech.), a form of steam engine in which the steam that has been us…