Emily Dickinson Lexicon

MAS'SI-COT, or MAS'TI-COT, n. [Fr. massicot.]

Protoxyd of lead or yellow oxyd of lead, composed of one equivalent of lead and one equivalent of oxygen. Lead exposed to the air while melting, is covered with a gray, dusky pellicle. This pellicle carefully taken off, is reduced by exposure to the joint action of heat and air, to a greenish gray powder, inclining to yellow. This oxyd separated from the grains of lead by sifting, and exposed to a more intense heat sufficient to make it red hot, assumes a deep yellow color. In this state it is called massicot. Massicot, slowly heated by a moderate fire, takes a beautiful red color, becomes a salt composed of two equivalents protoxyd of lead and one equivalent deutoxyd, and obtains the name of minium. Fourcroy. Massicot is sometimes used by painters, and it is used as drier in the composition of ointments and plasters. Encyc.