156 ADHESIVES. [V. 



to become moist and injure the efficiency of the paper, a 

 water-proof adhesive surface is desirable, to which the grind- 

 ing powder may be attached ; and for this purpose it has been 

 proposed to use a solution of copal in hot linseed oil, to- 

 gether with Venice terpentine, Venetian red, a little litharge, 

 and caoutchouc. (Lond. Journ. xxxvi.l 



