Collecting and Laboratory Methods 195 



the insects are to be carried a long distance, or if the 

 weather is hot, it is necessary to slightly dampen the 

 cotton, or the mosquito will dry up and die. In this 

 manner adults can be sent alive in the mail, by placing 

 the vial in a mailing tube. Care must be taken that 

 the cotton is not so wet that the moisture will run 

 down the side of the bottle, as in this case the insect 

 will be caught and probably killed by the water. A 

 horse makes good mosquito bait, and, if it will stand 

 still, may be used to advantage. In catching mos- 

 quitoes in the sick-room, a glass or wide-mouthed 

 bottle will do ; Dr. Smith says that cotton fastened 

 to the bottom of this and well dosed with chloroform 

 is an aid in capture, stupefying the specimens, but 

 if they are to be kept alive this is not a good 

 method, being likely to kill them or, if they revive, 

 to affect their ovipositing. Also, it is not well to 

 allow mosquitoes in a sick-room to be captured by 

 the method used in the woods. 



Adult specimens for preservation may be killed by 

 chloroform or in a cyanide jar. The latter may be 

 easily made from a wide-mouthed bottle. In the 

 bottom of this place a small lump of cyanide of 

 potassium and cover the cyanide with liquid plaster 

 of Paris. When this hardens it will prevent the water 

 which results from the deliquescence of the chemical 

 from escaping and ruining the specimens. It is well, 

 for still further safety in this direction, to place on top 

 of the plaster a disk of blotting-paper. It should be 

 borne in mind that cyanide is one of the most deadly 

 poisons, and that its fumes are very active, a small 

 amount being fatal. The vial should be always kept 



