MISCELLANEOUS ARTICLES. 413 



during a drouth. We not only saw greater injury when a rain followed 

 spraying within two or three days, but secured the same results by 

 spraying soon after treatment with pure water. This also accords with 

 the view that the injury conies from the presence of soluble arsenic." 



4. " It would seem that spraying soon after the foliage puts out is less 

 harmful than when it is delayed a few days, or better, a few weeks. " 



5. " London purple may be used on apple, plum, cherry, pear and most 

 ornamental trees, but on these should never be stronger than one 

 pound to two hundred gallons of water. If the application is to be re- 

 peated, as it must be for the curculio to prove effective, or if it is to be 

 used in June or July, Paris green should be used in the same propor- 

 tion as above, or else we should use only one pound of London purple 

 to three hundred gallons of water. I now think this necessity is more 

 due to time of application than to the fact of increased quantity of the 

 poison." 6. " If the arsenites are to be usad on the peach to defend 

 against the curculio, Paris green only should be used, and that not 

 stronger than one pound to three hundred gallons of water." 7. "The 

 injury done to the foliage is never immediately apparent. It usually 

 shows somewhat the second day, but the full injury is frequently not 

 manifest till the fifth day, and often not till the tenth." 



The bulletin details experiments to determine if sufficient poison 

 falls upon the grass under heavily sprayed trees to cause injury to stock. 

 Samples of grass were analyzed and others were fed to a horse ; both 

 the chemist and the horse declared that the poison was not sufficient 

 to cause damage — an interesting conclusion. 



Professor Cook recites instances of heavy loss to bee-keepers in 

 neighborhoods where orchardists sprayed their trees while in bloom. 

 The adult and immature bees were alike killed. This destruction of 

 bees is entirely unnecessary, as there is no occasion whatever for 

 spraying trees when in bloom. 



BULLETIN NO. 6, OHIO EXPERIMENT STATION, 



Containing Notes of Experiments Upon Various Insects. By Clarence 



M. Weed. 



Mr. Weed has repeated .his experiments of a year ago upon the 

 destruction of the curculio on cherries and plums by means of London 

 purple. It has now been proved by several observers that the adult 

 curculio feeds upon leaves and fruits, and spraying with the arsenics 

 has become a settled practice in many parts of the country. Mr. 



