OF LEPIDOPTEROUS INSECTS. 207 
method. As soon as the operation is properly per- 
formed, the depredating insect perceives that the 
prepared specimen is no longer food for it, and will 
for ever cease to attack it ; but then every part 
must have received the poison, otherwise those 
parts where the poison has not reached will still he 
exposed to the enemy, and he will pass unhurt 
over the poisoned parts till he arrives at that part 
of your specimen which is still wholesome food for 
him. Now, the difficulty lies in applying the 
solution to very minute specimens without injuring 
their appearance; and all that can he said is, to 
recommend unwearied exertion, which is sure to 
he attended with great skill, and great skill will 
insure surprising success. I myself have attended 
to the preservation of insects with the assiduity 
which Horace recommends to poets :—‘ Nocturna 
versate manu, versate diurna.’ The result has 
heen astonishing success, and a perfect conviction 
that there is no absolute and lasting safety for pre- 
pared specimens in zoology from the depredations 
of insects, except by poisoning every part of them 
with a solution of corrosive sublimate in alcohol. 
« The tight boxes, and aromatic atmospheres, will 
certainly do a great deal, but they are liable to 
fail, for this obvious reason, viz. that they do not 
vender for ever absolutely baneful and abhorrent 
to the depredator, that which in itself is nutritious 
and grateful to him. In an eyil hour, through 
