THE CANADIAN ENTOMOLOGIST. 113 



For the benefit of those who were not present at that meeting, I will 

 again describe the process of making : 



The material used is beeswax, with a small quantity of resin added 

 to increase the hardness and to raise the melting point. This mixture of 

 beeswax and resin is kept heated almost to the boiling point ; if the tem- 

 perature falls much lower you will not be able to form a smooth cell. 

 Place your slip on the turntable and set in rapid motion, then with a 

 moderately thick brush apply a droj) of the hot wax to the slip, which, 

 being cold, cools the wax rapidly, rendering the cell visible at once ; apply 

 the wax drop by drop until the cell is a little deeper than is required for 

 your material ; allow it to cool thoroughly, and before removing from the 

 turntable, take a sharp knife and trim it down to the proper thickness. 

 You may also taper the outside of the cell towards the centre and the 

 inside towards the circumference, leaving the base of your cell wider than 

 the top, but always have your cell wide enough at the top, so that your 

 cover glass will not come quite to the edge, leaving a small margin for 

 the cement ; a shallow depression may also be turned in the top to receive 

 the cover glass. This cell answers for such mounting media as Canada 

 balsam, or any glycerine jelly ; but for media containing oil, it will be 

 necessary to varnish the cell inside with some material that will not be 

 acted upon by the mounting medium. These cells anbvver for almost any 

 kind of material, if treated in the manner described, but when the mount- 

 ing medium is of a very thin or watery nature, it is advisable to slightly 

 heat the slip after you have your cell made and before turning it down, 

 in order to make a perfect contact between the wax and glass. 



For mounting transparent aquatic insects, take a cell of proper depth, 

 transfer your insect to it with a small quantity of water, and add a drop of 

 Pyroligneous acid ; as soon as the acid reaches the insect it dies at once ; 

 place the cover glass in position, and after carefully absorbing any water 

 that may have run over, cement down the cover. 



Semi-transparent insects should be placed in a solution of Carbolic 

 acid and Turpentine (one part of the former to three of the latter) and 

 allowed to remain until clear. Ordinary crystallized Carbolic acid may be 

 used in preparing this clearing solution, but I think the best results are 

 obtained by using the C. P. acid ; the crystals of pure Carbolic acid are 

 needle-shaped and colourless, while the ordinary commercial acid comes 

 in white flaky crystals. The Turpentine will also require some attention, 

 for, as ordinarily sold, it is hardly suitable for this purpose. 



