234 ENTOMOLOGY. 



strong alcohol, enough to make one quart. I have not 

 stated the quantity of naphtha, since there are some vari- 

 eties of light petroleum in commerce which dissolve in alco- 

 hol only to a slight extent. These should not be used. 

 The heavier oils which mix indefinitely with alcohol are the 

 proper ones, and for the two pints of mixture ten to twelve 

 fluid ounces of the naphtha will be sufficient. Care should 

 be taken to test the naphtha on a piece of paper. If it 

 leaves a greasy stain which does not disappear after a few 

 hours, it is not suitable for this purpose. 



" The best form of atomizer is the long, plated, reversi- 

 ble tube; it should be worked with a gum-elastic pipe hav- 

 ing two bulbs, to secure uniformity in the current. The 

 atomizing glass tubes and the bottle, which usually accom- 

 pany the apparatus, are unnecessary; a common narrow- 

 necked two-ounce bottle will serve perfectly to hold the 



fluid." 



Preparing Insects for the Cabinet. Dried insects may be 

 moistened by laying them for twelve or twenty-four hours 

 in a box containing a layer of wet sand, covered with one 

 thickness of soft paper. Their wings can then be easily 

 spread. Setting -boards for spreading the wings of insects 

 may be made by sawing deep grooves in a thick board, and 

 placing a strip of pith or cork at the bottom. The groove 

 may be deep enough to allow a quarter of the length of the 

 pin to project above the insect. The setting-board usually 

 consists of thin parallel strips of board, leaving a groove 

 between them wide enough to receive the body of the in- 

 sect, at the bottom of which a strip of cork or pith should 

 be glued. The ends of the strips should be nailed on to a 

 stouter strip of wood, raising the surface of the setting- 

 board an inch and a half, so that the pins can stick through 

 without touching. Several setting-boards can be made to 

 form shelves in a frame covered with wire gauze, so that 

 the specimens may be preserved from dust and destructive 

 insects, while the air may at the same time have constant 

 access to them. The surface of the board should incline 



