270 



BOARD OF AGRICULTURE. [Pub. Doc. 



London Purple, — Owing to the variable nature of this 

 substance, it has not come into such general use as has Paris 

 green. Upon crops that are not injured by the soluble 

 arsenious acid it contains it may be safely used. 



Arsenate of Lead. — The peach, Japanese plum and the 

 cherry foliage are injured by the use of Paris green ; but 

 the arsenate of lead is said to be equally as effective as 

 the latter, and not injurious to the foliage, even when used 

 in large quantities. 



Kerosene. — Up to within a year or two this insecticide 

 has been used in the form of kerosene emulsion, and with 



Fig. 5. 



good results ; but some difficulty seems to have been ex- 

 perienced in making a reliable emulsion under various con- 

 ditions, and injury has often resulted. It has been found, 

 however, that clear kerosene or kerosene and water, applied 

 in a fine spray or mist, and on hrigJil, airy days, is safe, 

 more effectual and not more expensive, when the labor of 

 making the emulsion is considered. Neither the emulsion 

 nor the kerosene and water should be applied in moist, 

 cloudy weather. 



Pyrethrum. — This powder, called also Persian or Dal- 

 mation insect powder, is an insecticide that acts very quickly 

 upon the breathing organs, killing delicate insects like the 



