What is "vitrite"

Vitrite \Vit"rite\, n. [L. vitrum glass.] A kind of glass which is very hard and difficult to fuse, used as an insulator in electrical lamps and other apparatus.

n. A kind of glass which is very hard and difficult to fuse, used as an insulator in electrical lamps and other apparatus.

Vitrite, also known as foam glass, is a very low fusing point black glass mainly used for the insulation base of electric lamps. It used to be made by the Vitrite Company.