154 THE ENTOMOLOGIST. 



SO that in no part does it touch the plaster sides. When the 

 box is used pour water on tlie plaster, so as to thoroughly 

 saturate it; stick the specimens on the table, put on the lid, 

 and place the whole in the pantry or cellar to be kept cool. 

 To guard against fungi appearing in the box some corrosive 

 sublimate (bichloride of mercury) may be dissolved either in 

 the water mixed with the plaster or in that first used in 

 damping the box ; the former plan is perhaps preferable. 

 From one or two days to a week, according to the size of the 

 insect, will be needed for the specimens to get into fit 

 condition for effective setting. The great point is to have 

 them thoroughly relaxed, or they are apt to spring. To 

 prevent this, also, they should be left ibr a long time on the 

 boards, — a week or ten days at least is required ; but with 

 the above precautions 1 have never found it necessary to use 

 any such clumsy contrivance as sticking the wings in position 

 with liquid-glue, &.c. This can only be required when the 

 insects have not been sufficiently relaxed. Of course I claim 

 no originality for the above method. I believe it is used by 

 many entomologists, but I think it possesses several advan- 

 tages compared with the plans mentioned in mo.st books. 

 Although immersed in a very moist atmosphere the specimens 

 never become saturated with water, as is often the case when 

 a simple wetted box is used. The bichloride of mercury 

 seems effectually to prevent any appearance of mould, and 

 the rapid evaporation from the porous plaster keeps the air 

 in the box at so low a temperature that even in the height of 

 summer no signs of decomposition are perceptible, while 

 the neatness of the affair and its constant readiness for use 

 are additional recommendations. I have employed one for 

 several )'ears, and it is still as serviceable as ever. When 

 carefully manipulated, relaxed insects, particularly butter- 

 flies, &c., look quite as well as those set in their original 

 state. 1 have hundreds of Diurni and Bombyces in my 

 collection prepared in this way, and he would be a bold man 

 who would undertake to pick them out from the others. 

 Indeed, there is one element in connection with such perfect 

 methods of relaxing worthy of consideration : inasmuch as 

 the insects retain all their pristine beauty after undergoing 

 the process, unscrupulous collectors and dealers are enabled 

 to pass off foreign specimens as " true Britons" with impunity 



