INSECT PESTS AND POISONING. 343 



ings of the Entomological Society of Washington," vol. i., No. 2, 

 p. 113, a very interesting paper on " Museum Pests," found in 

 treating some boxes of coleoptera that were infested with Tro</<> 

 i/crtna that both bisulphide of carbon and naphthaline killed all 

 larvae and imagoes, and held all the eggs in a dormant condition, 

 even through the summer months, until the poison had all 

 evaporated, when the eggs began to hatch. 



At present naphthaline in the form of crystals has become the 

 most popular of the various volatile poisons, and among or- 

 nithologists, mammalogists, and entomologists is very generally 

 used. It prevents mould, destroys bacteria and schizomycetes ; 

 the salt is perfectly neutral, is not poisonous to man, and is 

 cheap, costing only twenty-five cents per pound. 



POISONING TEXTILE FABKICS AND SKIN CLOTHING. Objects of 

 this class can not be put through any liquid poison, for the 

 reason that some would be made hard and stiff, some would lose 

 their colors, and all would come out in bad shape generally. 

 To meet the exigencies of such cases one alternative is to 

 poison the atmosphere of an air-tight case with some of the 

 volatile poisons already mentioned, and the other is to treat 

 each article with some powerful liquid poison, applied as a fine 

 spray with an ordinary atomizer of gutta-percha, which can be 

 purchased for from one to two dollars. The immense collec- 

 tions of the department of ethnology in the National Museum 

 have necessitated a great amount of poisoning in both these 

 ways, especially the latter, which has the merit of being perma- 

 nent. In the "Smithsonian Report for 1887," vol. ii., pp. 549- 

 558, Mr. Walter Hough has published a very complete, lucid, 

 and valuable paper on "The Preservation of Museum Speci- 

 mens from Insects, and the Effects of Dampness," which every 

 zoological conservator should read and hold for ready reference. 



In spraying large objects Mr. Hough uses either a Shaw \- 

 Geary No. 2 air compressor (cost, $15) or a four-nozzle gutta- 

 percha atomi/rr (*2.50), and the spray is from the following so- 

 lution : 



Saturated solution of arsenic acid and alcohol 1 pint. 



Strong carbolic acid 25 drops. 



Strychnine 20 grains. 



Alcohol (strong) 1 quart. 



Naphtha, crude or i efined 1 pint. 



