This term is applied technically to the removal of varnish from old pictures, and it is scarcely necessary to say that if this were attempted by means of chemical solvents of gum-resins, which form the basis of most varnishes,' old or new, the operation would be very hazardous in skilful hands, while in those of an ignoramus the underlying picture would (as has frequently been the case) be sacrificed, by the solvent (turpentine, for example), after attacking the varnish, performing the function of dissolving the oil of the picture. This barbarous application of varnish solvents has acquired the appropriate name of "skinning," a term which implies the removal not only of the varnish, but the picture itself. Although it is possible by means of chemical solvents to remove coats of varnish from the surface of oil paintings, the plan adopted by Blaker is by far the most safe, and in practical hands the most secure. It consists in rubbing the varnished surface gently with the finger, by which the resinous matter works up into a powdery condition, and this action is kept up with great care until the colours of the picture, as will be readily understood, become exposed to view.