154 THE ENTOMOLOGIST. 
so that in no part does it touch the plaster sides. When the 
box is used pour water on the 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 for a long time on the 
boards,—a week or ten days at least is required; but with 
the above precautions | 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 most books. 
Although immersed in avery 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 years, 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 alter undergoing 
the process, unscrupulous collectors and dealers are enabled 
to pass off foreign specimens as “ true Britons” with impunity 
