PREPARATION FOR DISSECTING PANS. 215 



soluble in strong solutions and consequently is not satisfactory for 

 dissection in solutions of alcohol stronger than about fifty per cent. 



Preparation (B) is practically insoluble in ninety-six per cent, alcohol 

 as well as in formal and water, and is consequently satisfactory for 

 dissection in these solutions; but this preparation does not adhere to 

 the pans as tanaciously as preparation (A), and it might also be im- 

 proved by being made slightly darker in color, 



COST. 



Coal tar and resin are usually sold by dealers in plumbing material, 

 the former at twenty-five cents per gallon, and the latter at five cents 

 per pound. Linseed oil is handled by dealers in paint. It is retailed at 

 from forty cents to eighty cents per gallon. Paraffin may be obtained 

 from druggists or dealers in laboratory supplies at about twenty cents 

 per pound. 



According to the above prices the approximate cost of the preparations 

 would be as follows: 



PREPARATIOX A. 



1 pound linseed oil fO 08 



2 pounds coal tar 08 



8 pounds resin 40 



2 pounds paraffin 40 



Total 13 pounds .fO 96 



Cost per pound |0 07 5-7, 



PREPARATION B, 



2 pounds coal tar |0 08 



4 pounds resin 20 



10 pounds paraffin 2 00 



Total 16 pounds |2 28 



Cost per pound |0 I414. 



The amount of either of the preparations required to cover the bottom 

 of a dissecting pan 5x8 inches, about five-eights inch deep, weighs approxi- 

 mately one-half pound, making the cost of preparation (A) per pan about 

 four cents, and of preparation (B) about seven cents. 



