PRESERVING INSECTS. 237 



immersion of from a quarter of an hour to an hour, accord- 

 ing to the size of the insect, the pin is not affected by the 

 corrosive sublimate, but it is better to unpin the insect 

 previous to immersion, and then pin it when almost dry. 



For cleaning insects ether or benzine is excellent, applied 

 with a hair-pencil; though care should be taken in using 

 these substances, which are very inflammable. 



After the specimens are placed in the cabinet, they 

 should be further protected from destructive insects by 

 placing in the drawers or boxes pieces of camphor wrapped 

 in paper perforated by pin-holes, or bottles containing 

 sponges saturated with benzine or oil of sassafras. The 

 collection should be carefully examined every month; the 

 presence of insects can be detected by the dust beneath 

 them. Where a collection is much infested with destruc- 

 tive insects,* benzine should be poured into the bottom of 

 the box or drawer, when the fumes and contact of the ben- 

 zine with their bodies will kill them. The specimens them- 

 selves should not be soaked in the benzine if possible, as it 

 renders them brittle, f 



* The common museum pests are AntJirenus varius, A. mus&orum, 

 Atta genus pellio, Trogoderma tar sale, and Dermestes lardarius, be- 

 sides Tinea pellionella, Megatoma, and Atropos pulsatm-ius; in Cali- 

 fornia Perimegatoma mriegatum has proved destructive to collections. 

 Ptinusfur (Fig. 269) is also liable to occur. 



f We find by placing a small piece of cyanide of potassium in an 

 open short vial for a fortnight in an insect drawer that it may be 

 thoroughly disinfected; for permanent use naphthaline cones are 

 effective. Naphthaline cones, while not killing the larvae, repel 

 adult anthreni, etc., and should be kept constantly in boxes or 

 drawers. Mr. Schwarz advocates the use of " white carbon," which 

 is naphthaline sold in the form of small, square rods, costing only 8 

 cents a pound wholesale, and which is much purer than the naph- 

 thaline cones now in the market. When broken up into small 

 pieces, and wrapped in thin paper, it can be conveniently used in in- 

 sect boxes or drawers. Mr. Akhurst uses a preparation consisting of 

 3 parts of creosote or crude carbolic acid and 1 part oil of pennyroyal, 

 applied to the seams, grooves, and edges of boxes or drawers to keep 

 out museum pests. Mr. J. B. Smith urges the use of bisulphide of 

 carbon, which both serves to check the development of the eggs and 

 to destroy the recently-hatched larva 1 of museum pests. He finds 

 that the only chances of safety from infection ' consist in constant 



