332 THE ENTOMOLOGIST. 



made, through the medium of the ' Entomologist,' to answer the 

 chief points upon which Mr. J. R. Cattle asks for information. 



With regard to killing. There is, I think, no doubt but that 

 the cyanide-bottle, kept in good condition and not allowed to 

 retain damp, is the best mode of killing insects of all orders ; but 

 in the case of some of the larger moths, such for instance as the 

 Sphingidse, an injection of strong nicotine will be found more 

 quickly effectual. A simple method for administration is to dip the 

 point of a needle in the nicotine of a pipe, and make a puncture 

 underneath the thorax of the insect, after the latter has been stupi- 

 fied by strong ammonia or chloroform fumes. The cyanide-bottle 

 is quite harmless to the colours of all insects, with the exception 

 of some " greens," such for example as the green of the " emeralds." 

 To kill such insects, I consider bruised laurel shoots are better 

 than the vapour of chloroform, which is apt to make the wings so 

 rigid as to render the difficulty of setting properly very great. If 

 it be desired to set an insect immediately after killing, oxalic acid 

 will prove to be the best poison, as there seems to be little or no 

 rigor mortis consequent upon the use of this acid. 



As to preservation. The most important point about the 

 preservation of insects primarily is, that they should be allowed 

 to remain upon the setting-board until they are quite dry ; and, 

 in the second place, I think it is a great mistake not to periodi- 

 cally (say once a month) remove the glass-tops from the drawers 

 of the cabinet to allow exposure of the specimens to the free 

 atmosphere of a well-aired room, in which the cabinet should be 

 kept. Never place specimens from other collections in the 

 cabinet without previously dipping them in corrosive sublimate 

 in alcohol, or some like preparation. Under these conditions 

 moulds and mildew need not be feared. The cabinet should be 

 constructed of mahogany in preference to oak, for oak is much 

 more subject to gather and hold damp than mahogany. Corrosive 

 sublimate in alcohol is the best thing to paint the bottom of the 

 drawers of the cabinet with ; and although it is absolutely fatal 

 to insect life, it is doubtful as to how long it remains a preserva- 

 tive. If the drawers of the cabinet be kept well aired and the 

 cells well filled with naphthaline, no mites need be feared. All 

 insects (except perhaps those of a delicate green colour, which are 

 usually affected by very little) imported from foreign collections, 

 however, should be dipped, as described by Mr. Cattle, in corrosive 

 sublimate in alcohol before being introduced into the cabinet. 



As to grease. There is no doubt that grease is, as Dr. Guard 

 Knaggs holds, a result of decomposition; and as far as my expe- 

 rience goes there is really no certain preventive. It is certainly 

 advisable to stuff the bodies of all large moths before the contents 

 become hard, as the Rev. Joseph Greene suggests in ' The Insect 

 Hunter's Companion,' pp. 77, 78. As a cure for grease I would 

 recommend slaked-lime, used in the manner described by Mr. J^ 



