PAINTS, DYES, AND VARNISHES 



a resin in an essential oil, is a solution of damar resin in 

 turpentine. As in the case of shellac varnish, the resin 

 is not completely dissolved, and the solution is accom- 

 plished without the aid of heat. Such a varnish never 

 becomes very hard, and is not very durable. The film 

 left by damar varnish is not simply a thin layer, but a 

 combination of the damar resin and the residue always 

 left by turpentine on evaporation. In this respect it 

 differs from the spirit varnishes, in which the alcoholic 

 solvent evaporates completely, leaving the original 

 resin as the covering film. 



These three kinds of varnishes just described may 

 be taken as the predominating types of varnishes in 

 general use. But the number of modifications and com- 

 binations of these, their mixtures with paints and stains, 

 and their use in secret formulas of proprietary mixtures, 

 which are placed on the market under many scores of 

 names, is endless. Thus the "japans," which are 

 numbered by dozens, are various combinations of var- 

 nishes and driers; while lacquers, enamels, etc., are 

 various combinations adapted to special purposes. To 

 go into details about even the most important of these 

 substances would require volumes; and even then the 

 treatment would not be complete, since so many of 

 them are patented trade-secrets, not available for 

 publication. It suffices fully for our present purpose, 

 however, to give a concise idea of the principal sub- 

 stances used as bases for these combinations. 



VOL. vm. 21 



