Dissolve 4 parts of India rubber in 34 parts of coal tar naphtha- aiding the solution with heat and agitation, add to it G4 parts of powdered shellac, which must be heated in the mixture, till the whole is dissolved. While the mixture is hot it is poured upon metal plates in sheets like leather. When required for use, it is heated in a pot, till soft, and then applied with a brush to the surfaces to be joined. Two pieces of wood joined with this glue can scarcely be sundered.