26 



MISC. PUBLICATION 679, U. S. DEPT. OF AGRICULTURE 



Preliminary heating. — The mount should now be covered with an 

 inverted tray and allowed to heat for about 5 minutes until the resin 

 becomes workably fluid. 



Spreading the resin. — As soon as the resin flows freely it should be 

 spread uniformly over the surface of the mount (fig. 8, A) so that no 



Figure 8. The thermoplastic cementing resin, previously heated to 110° C. 1230° F.), 

 is applied while fluid (-4); it is then spread over the surface of the mount with a glass 

 rod bent like a hockey stick (/?). 



