April, '04] 



ENTOMOLOGICAL NEWS. 



129 



cents each. The most satisfactory size is about six inches 

 long by three-quarters of an inch in diameter. It is well to 

 have more than one for fear of accident, and also that too 

 many moths may not be in the same tube at the same time. 

 Three or four can easily be carried in top coat pocket, and 

 when I expect a big day's work I load both top coat and vest 

 pockets. 



The cyanide should be crushed into small lumps, about size 

 of buckshot, and put in bottom of tube from one-half to three- 

 quarters of an inch deep ; on top of this put a layer of saw- 

 dust one-quarter to one-half inch thick, and on top of the 

 sawdust pour a teaspoonful of liquid plaster-of-paris. The chem- 

 ical action caused by the contact of the sawdust and cyanide very 

 much increases the strength of the latter. Leave 

 open for a couple of hours and then push a small 

 piece of absorbent cotton in the tube, shoving it 

 down as flat as possible against the plaster. This 

 will prevent the moths from sliding around over 

 the smooth surface of the plaster and rubbing off 

 their scales. Fig. 13 shows a test-tube properly 

 charged, and it is surprising, considering the very 

 small amount of cyanide, how long its strength 

 continues at full power. I have some that are 

 still as good as new that were made two and three 

 years ago. Their length and slightly flared mouth 

 make it particularly easy to manipulate them in- 

 side the net. But they are much more fragile 

 than the ordinary bottle or jar, and the greatest 

 care should be used, in case of an accidental 

 break, to dig a little hole and bury all the frag- 

 ments in the earth. If a finger is cut by the 

 sharp edge of the broken glass, get it immediately 

 into water, rubbing vigorously to get all the 

 poison out of the wound. 



COLLECTING Box. The best boxes are made 

 of thin sheet zinc, which does not rust like common tin, nor 

 verdigris like brass. My boxes are oval in shape, and are 

 cork-lined inside on both bottom and top. 



Two sizes are convenient to have, the smaller about 5 by 3 



