KILLING OF INSECTS. 265 
death ensues. A crow-quill must be shaped into a 
point, like a rather long pen, this point dipped into the 
prussic acid, and an incision made with it immediately 
beneath the head into the middle of the shoulders of the 
creature, so as to permit the fluid it contains to enter 
into the body of the insect. Immediately after this, in 
every instance in which I have tried it, a privation of 
sensation appears to take place, the corporeal action of 
the creature ceasing, a feeble tremulous motion of the 
antennse being alone perceptible ; and these parts seem 
to be the last fortress that is abandoned by sensation, as 
they are the primary principle of sensibility when life 
is perfect : extinction of animation ensues, not a mere 
suspension, but an annihilation of every power, muscu- 
lar and vital. As one example of the decisive effects 
of this fluid, I shall instance the common wasp, a crea- 
ture so remarkably tenacious of sensation, or so long 
retaining a muscular power, that it may remain, as every 
one knows, for days crushed in the window, an appa- 
rently dead insect, yet upon pressing the head, the sting 
will be so protruded as to give a very sensible pain to 
the finger it should meet with ,* but upon the prussic 
acid being injected into this creature as above, when in 
full vigor, in the course of less than half a minute a 
loss of vitality ensues, the action of the muscular fibre 
ceases altogether, and no pressure can incite it again 
into action. The sudden effect of this liquor is not so 
generally known as from humanity and expediency 
might be wished. Who first devised the experiment I 
am ignorant ; but any repetition of means whereby a 
necessary end can be obtained by the least painful and 
brief infliction, will hardly be considered as super- 
fluous. 
This subject naturally introduces the preservation of 
the creatures after their death, and the young ento- 
mologist is not perhaps sensible from experience of the 
injury some species of insects will effect in the select- 
ed specimens of others of this race, and may lament, 
when too late, the separation of the wings, limbs, and 
bodies of his collection by these tiny depredators (ptinus 
fur, acararus destructor). Mr. Waterton’s recipe for 
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