STAINS, REAGENTS, &c. 51 



Beown Cement. 



A. Best orange shellac pulverised 4ozs. 



Alcohol 92% 300cc. 



/j'. A saturated solution of pure rubber in petroleum ether ... 60 cc. 



C Best gold size 120 cc. 



Add B and C to A. Filter for use. 



Oxide of Zinc. 



Make a saturated solution of gum dammar in pure benzol; filter this into a 

 mortar, and add as much oxide of zinc as the solution will take up by pounding. 

 Now thin down to the required consistency with pure benzol, and filter through 

 fine muslin. Now add to the solution as much gold size as will impart to it a 

 creamy tint, when shaken up. 



ASPHALTUM. 



A saturated solution in pure benzol. Filter for use. 



