I'EOCEEDINGS OF THE THIRD ENTOMOLOGICAL MEETING 975 



cut in two and the smallest size has these plates cut in four. The advant- 

 ages of using photographic quarter-plates is that the glass is of very 

 good quality and is practically a waste product. The tin frame is made 

 of such a size that the distance between the two plates is sufficient to 

 accommodate the legs and body of the insect. 



The butterfly is attached to one of the glasses by a cement made 

 of four parts of resin and one of beeswax. The glasses are attached 

 to the frame by a cement containing four parts of resin, four parts 

 of Sealing-wax and one part of beeswax. The constituents are melted 

 together and sufficient lamp-black is stirred in to give it a black colour 

 if black sealing-wax is not available. 



In mounting the butterfly, the glass to which it is to be attached 

 is first fixed in position in the frame. Marks are made on the outside 

 of the glass with a grease-pencil to indicate points to which the adhesive 

 composition is to be applied. The composition is melted over a flame 

 and small drops of it are put on at the points indicated by means of a 

 thin pointed glass rod. The butterfly is set on a flat piece of cork upper 

 side downwards. A pin may be used to attach it in position while the 

 wings, are being set but must be removed as soon as this is done. It 

 is advisable to allow the set butterfly to dry in the presence of carbide 

 which is a most efficient desiccating agent. When thoroughly dry 

 the butterfly is removed from the sheet of cork and placed with its 

 back upwards over the mouth of a bottle of suitable size. The glass 

 in the frame is warmed so that the spots of composition are properly 

 melted. It is then lowered into position over the butterfly until the 

 latter adheres. The frame is then laid on the table and some of the 

 black composition is placed along the ledge on which the second glass 

 is to rest. It is warmed with the help of a Bunsen burner and the glass 

 ■is dropped into position. It is advisable to cool the edges of the frame 

 rapidly with the help of water so -that the composition sets before the 

 air in the box has had time to cool. Otherwise the cooling of the air 

 may result in a decrease of pressure and air from the outside may- be 

 drawn in through the layer of composition under the edge of the glass 

 and the box may not be airtight. 



It is not difficult to mount the butterfly in an atmosphere of carbonic 

 acid gas in these boxes. To do this I made a glass-walled box whose 

 bottom was a little larger than the frame of my container. Carbonic 

 acid gas was led into this from a tube provided at the bottom and 

 replaced the air by displacement. The box containing the butterfly 

 was lowered into the glass case. Gas was allowed to enter during a 

 few minutes. The glass lid was then lowered into position. For this 



VOL. Ill L 



