INTRODUCTION. 21 



Camphor water, - 50 grammes; 



Distilled water, 50 grammes; 



Glacial acetic acid, - 0.5 grammes; 



Crystallized chloride of copper, 2 grammes; 



Crystallized nitrate of copper, 2 grammes. 



Dissolve and filter. 



When mounting with this copper solution the cell should be 

 made and the cover cemented down with shellac. With almost any 

 other cement failure is pretty certain, as the cement will surely 

 run under and ruin the preparation. After the shellac is hard, it is a 

 good plan to add some of Brown's rubber cement around the cover. 

 This is entirely transparent and will make the mount more secure, 

 and at the same time add something to the beauty of the finish. 



TRENTON, N. J., 1892. 



