For delicate specimens, also, the collecting bottle may consist of a test-tube of about the size of Fig. 92. This is half filled with loose, thin strips of soft white paper. A piece of cyanide about the size of a pea is then wrapped carefully in paper and so placed in the middle of the strips that it can not come in contact with the sides of the glass. Some prefer to pin the paper containing the cyanide to the lower surface of the cork. The latter should be rather short and tapering toward its lower end. It is longitudinally perforated through its center by a round hole just large enough to insert a goose-quill, which is cut straight at the lower end and obliquely at its upper end. By means of this goose-quill the specimens may be introduced into the bottle without taking off the cork. This form of cyanide bottle lasts for only one day's collecting, except in cold weather, and in very warm weather it is advisable to take two prepared bottles along, so that the first used can be stowed away as soon as the cyanide begins to moisten the paper strips. Most insects are quickly killed in such a bottle, but some Coleoptera must be left in for five or six hours, while others resist death for a still longer time. This is especially true of the Coleopterous families Curculionidae, Trogositidae, and Tenebrionidae. Submersion in alcohol will prove a satisfactory method of killing these or other beetles with similar vitality. [Illustration: FIG. 93.--The cyanide bottle with blotting-paper lining (original).] _Other Agents._--Prof. E. W. Claypole has found the use of benzine or gasoline very cheap and satisfactory for killing Lepidoptera, as the largest are at once killed thereby without injury to their scales. (_Can. Ent._, XIX, p. 136.) He squirts it onto the specimen within the net or in the open air by means of a druggist's dropping tube. Hot water kills rapidly and leaves the specimens in good flexible condition for mounting. The heads of large insects may be held for a few moments in the water, while smaller specimens should first be thrown into a corked bottle and the bottle submitted to heat. Where the laurel grows its bruised leaves may be used in place of cyanide; they kill less quickly. The leaves of the Laurel-cherry (_Prunus laurocerasus_), a plant commonly grown in England for screens and hedges, are also used for this purpose. Some collectors, with indifferent olfactory sense, moisten the cork of their boxes with creosote. Its killing power lasts for several days. A few whiffs from a cigar, when nothing else is at hand, will also kill many of the more tender insects.