21G 



applied to the foliage of plum, apple, and cherry has la no case done serious harm, 

 unless stronger than 1 pound to 50 gallons, and the average injury to plum foliage, 

 when applied in the proportion of 1 pound to 25 gallons, is less than 10 per cent. 



Atteiitioii is called to the fact that these results do not agree with 

 those reported in Bulletin No. 53 of the Michigan Station (See Ex- 

 periment Station Record, Vol. I, p. 227). 



Increased injuries to foliage from allowing the arsenites to remain in 

 water for a time before being ajipUed. — The tabulated data show that in 

 the case of Loudon purple the injuries were about the same as when 

 this poison was applied in the ordinary way. " The water from Paris 

 green, which is hardly at all soluble, did but slight harm in auy case. 

 Arsenic water did very serious harm. As dilute as 1 pound to 200 gal- 

 lons it destroyed 90 per cent of plum foliage, and 25 per cent of cherry 

 foliage." 



Effects of adding paste to arsenites mixed in irater. — "When treating 

 plum-trees for the destruction of the plum curculio, in the spring of 

 1889, 1 used one half ounce of flour made in paste to each gallon of the 

 mixture of London purple in water. So much injury was done to the 

 foliage that it was thought best to determine whether or not the paste 

 was in any measure accountable for it." The results of applications 

 made for this purpose, as recorded in a table, indicate that the addi- 

 tion of paste materially increased the injury to foliage. 



Soap added to arsenical mixtures. — "London purple, Paris green, and 

 white arsenic were also applied to foliage in water that had been made 

 slightly soapy, and considerable evidence of increased injury, as the 

 result, was obtained. The applications were not repeated, and final 

 conclusions can not be drawn." 



Best time to apply arsenical mixtures. — As far as the experiments per- 

 formed by the author are concerned, the time of day does not seem to 

 affect the result of the application of arsenites, and rains occurring 

 soon after such applications only lessen the injury to foliage. 



Lime added to the arsenites to prevent injury to foliage. — The first experi- 

 ment in which milk of lime was added to the arsenical mixtures was 

 made in the fall of 1881). The results were so encouraging that similar 

 experiments were made this year, the results of which are recorded in 

 two tables. "The applications were made upon the foliage of plum, 

 apple, cherry, peach, alder, locust, poplar, grape, and sqnash." The 

 average percentages of injury from Loudon purple and Paris green 

 with and without lime were as follows: 



