(Cu. Eq. = 31.75.) Cuprum. Copper. Appendix B. Copper, in the form of foil, thin and bright.

Prop. & Use. Metallic copper has a well-known peculiar red colour; sp. gr. 8.86; malleable and ductile; oxidizable in the air, especially when in contact with acids, alkalies, or fatty bodies: it is employed to test the purity of hydrochloric acid; it can also be used for the detection of silver, when put into a solution of a salt of silver; the latter metal is deposited upon it as a white powder. Mercury would also be precipitated, but may be distinguished from silver by its running into globules when rubbed. Copper is also employed in Reinsch's test for arsenic.