1032; The perfect preservation of a herbarium is much impeded from the attacks of insects. A little beetle, called Ptinus fur, is more especially the pest of collectors, laying its eggs in the germens or receptacles of flowers, as well as on the more solid parts, which are speedily devoured by the maggots when hatched; and by their devastations, paper and plants are alike involved in ruin. The most bitter and acrid tribes, as Euphorbia, Gentiana, Prunus, the Compositï¾µ, and especially willows, are preferred by these vermin. A specimen of the last-mentioned family can scarcely be thoroughly dried before it is devoured. Ferns are scarcely ever attacked, and grasses but seldom. To remedy this inconvenience, a solution of corrosive sublimate of mercury in rectified spirits of wine, about two drachms to a pint, with a little camphor, will be found perfectly efficacious. It is easily applied with a camel-hair pencil when the specimens are perfectly dry, not before; and if they are not too tender, it is best done before they are pasted, as the spirit extracts a yellow dye from many plants, and stains the paper. A few drops of this solution should be mixed with the glue used for pasting. This application not only destroys or keeps off all vermin, but it greatly revives the colours of most plants. After several years' experience, no inconvenience has been found from it whatever, nor can any dried plants be long preserved without it. (Smith.) Dr. Lindley has found that suspending little open paper bags, filled with camphor, in the inside of the doors of his cabinets, is a very effectual mode of protection from insects. It will not destroy the larvï¾µ; already there, or that may be carried in by fresh specimens ; but when such larvï¾µ become perfect insects, they quit the cases without leaving any eggs. (Lindley's Introd. 1st ed. p. 468.)
