ENTOMOLOGICAL INSTRUMENTS, &C. 559 
dead insects, you will of course wish to know how they 
may be kept out of your drawers, or banished when de- 
tected there. Camphor is the general remedy recom- 
mended. The cavity closed by the rabbet of the glass 
frame affords a good receptacle for this necessary article : 
put some roughly powdered into each side, and be care- 
ful to renew it when evaporated. This will generally 
preserve your insects, as will be seen from the result of 
the following experiment. — Some insects in a chip box 
having become much infested by mites and Psocus pul- 
satorius, I placed under a wine-glass several of each 
along with roughly-powdered camphor : at the end of 
twenty-four hours the mites were alive ; but at the end 
of forty-eight they were all apparently dead, and did not 
revive upon the removal of the camphor. The speci- 
mens of Psocus all appeared dead in an hour, and never 
revived. If the camphor be put only into one side of a 
drawer, and in a lump, though perhaps it may keep out 
mites, &c, it will not expel them. 
I am, &c. 
