Keeping a supply of paradichlorohenezene or naphthalene in insect boxes for protection against dermestids has always been a problem. Small cloth bags or wire screen boxes are frequently used hut are a nuisance to fill and require several pins to hold them in place. The method used for protecting the collections at the Vineland Station Laboratory appears to be more convenient.

Rolls of dental cotton, which are about three-quarters of an inch in diameter, are cut into pieces two inches long and mounted crosswise on ordinary office pins. Paradichlorobenzene is melted (M.P. 53° C.), most conveniently in a can placed in a vessel of hot water, and the pieces of cotton are dipped into it. The cotton becomes saturated almost instantaneously and is laid on a board until the paradichlorobenzene solidifies.