CATALOGUE OF INSECTS. 21 



London purple is a waste product much used at one time and with 

 advantage in many cases ; but it was never very favorably considered 

 by farmers generally because of its variability and its tendency to 

 burn foliage : hence it need not be further considered here. The 

 green arsenoid has all its advantages and none of its bad features. 



Another form of using the arsenical poisons may be conveniently 

 mentioned here, /. <?., dry and mixed with bran. Wheat bran seems 

 to be peculiarly attractive to caterpillars, especially cut-worms, who 

 will eat it in preference to their usual green food, and this weakness 

 we may take advantage of to their undoing. Mix paris green, white 

 arsenic or green arsenoid, i pound, with bran 50 lbs., making the 

 mixture as complete as possible so that each particle of bran may 

 carry its particle of poison. Against cabbage worms, especially the 

 loopers, sprinkle over the forming head liberally the dry mixture. 

 Against cut-worms a spoonful at the base of each hill to be protected 

 will be effective. In my experience it is better to moisten the bran 

 by adding water enough to make a mush, using also a little molasses 

 to make it somewhat sticky and causing it to remain moist the longer, 

 when cut-worms are to be killed. There is then no danger of the 

 material blowing away or becoming covered with sand, while the 

 sweet stuff seems to make it either more attractive or more easily dis- 

 covered. 



When an arsenical spray is to be used on a very smooth leaf, or one 

 that, like cabbage, sheds a watery mixture, the addition of 1 pound 

 of soap to every 40 or 50 gallons of water will be an advantage, 

 while it will do no harm in any case. Once thoroughly applied, 

 arsenic remains on the foliage a long time. It settles into the pores 

 of the leaf, and, as it is not soluble, remains there for weeks. It is 

 this fact that sometimes causes a premature ripening or dropping of 

 the leaves of sprayed trees, and this also makes the arsenate of lead 

 so lasting in its effects, because the very fine particles settle every- 

 where, while they do not so seriously interfere with the functions of 

 the leaf as do the larger crystals of paris green. 



The bordeaux mixture is not, strictly speaking, an insecticide; yet 

 few insects care to eat foliage covered with it, hence it serves as a re- 

 pellant. 



The formula is as follows : 



Sulphate of copper, 6 pounds. 



Quick lime, 4 pounds. 



Water 22 gallons. 



Dissolve the copper sulphate in 1 gallon of hot water, and in 

 another vessel slake the lime with a gallon of water; add the milk of 



