Naphthalene in the form of flakes (preferably) or moth balls is
effective when used at the rate of one-half to 1 pound to each 10 to 13
cubic feet of space. It is always better to use a larger rather than
a smaller quantity of these crystals Great care should be exercised
to keep tightly closed the trunks or chests of clothing with which
the naphthalene is stored. Naphthalene in chests opened frequently or
those carelessly left open for hours at a time, or in chests with large
cracks or warped covers, is not to be depended upon. Naphthalene should
be of good grade. It is best to purchase it put up in unbroken tin cans
of 1 pound or more capacity. Remember that naphthalene kills all stages
of the carpet beetles by means of the fumes given off during the slow
evaporation of its crystals and it is essential that these fumes be
closely confined. Naphthalene in bureau drawers, in closets frequently
used, scattered upon closet shelves, or beneath carpets is not to be
depended upon for absolute protection.