In addition to the words of wisdom posted by Gutenkauf about
the health risks of these two materials, you should know that
they are _different_ materials with different results.  Paradi-
chlorobenzine (PDB) is a repellent - it keeps insects away, but
it does not kill them.  Napthalene is a fumigant and kills
insects.  You need to read the label on mothballs, cakes, flakes
and crystals to see which chemical is in them.  It takes a ton
of napthalene (a pound per cubic foot) to be effective _and_
it is heavier than air, so infestations at the top of an object
may not be affected by napthalene placed near the bottom of the
object.
As indicated in an earlier post (thanks again Diane) neither
one of these chemicals has any effect on mildew, which is caused
by too high a relative humidity.

Janice Klein, The Field Museum
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