8 
The wet method.—Hither Paris green or London purple may be used 
at the rate of 1 pound to 100 to 250 gallons of water, or 1 ounce to 6 to 
15 gallons. The stronger mixtures are for such vigorous foliage as that 
of the potato, for the Colorado potato-beetle, and the greater dilutions for 
the more tender foliage of the peach or plum. An average of 1 pound 
to 150 gallons of water is a good strength for general purposes. The 
poison should be first made into a thin paste in a small quantity of 
water and powdered or quick lime added in amount equal to the poi- 
son used to take up the free arsenic and remove or lessen the danger 
of scalding. An excess of lime will do no injury. The poisons thus 
mixed should be strained into the spray tank or reservoir, care being 
taken that all the poison is pulverized and washed through the meshes 
of the strainer. The use of the lime is especially desirable in the case 
of the peach and plum, the foliage of which, particularly the former, is 
very tender and easily scalded. To the stronger foliage of the apple 
and most shade trees Paris green may be applied at. the strength of 1 
pound to 150 gallons of water without danger; with London purple it 
is always better to use the lime. 
If it be desirable to apply a fungicide at the same time, as on the 
apple for the codling moth and the apple scab fungus, the Bordeaux 
mixture! may be used instead of water, adding the arsenical to it at 
the same rate per gallon as when water is used. ‘The lime in this fun- 
gicide neutralizes-any excess of free arsenic and makes it an excellent 
medium for the arsenical, removing, as it does, all liability of scalding 
the foliage and enabling an application of the arsenical, if necessary, 
eight or ten times as strong as it could be employed with water alone. 
The arsenicals can not be safely used with most other fungicides, such 
as the sulphate of copper, eau celeste or iron chloride solution, the 
scalding effects of these in the mixture being greatly intensified. 
The dry method.—The following description applies to the pole-and- 
bag duster commonly used against the cotton worm: A pole 5 to 8 feet 


1Bordeaus mixture formula.—Into @ 50-gallon barrel pour 30 gallons of water, and 
suspend in it 6 pounds of bluestone in coarse sacking. Slack 4 pounds of fresh lime 
in another vessel, adding water slowly to obtain a creamy liquid, free from grit. 
When the bluestone is dissolved add the lime milk slowly with water enough to fill 
the barrel, stirring constantly. 
With insufficient lime the mixture sometimes injures the foliage, and it should be 
tested with a solution obtained by dissolving an ounce of yellow prussiate of potash 
(potassium ferrocyanide) in one-half pint of water. If there be insufficient lime in 
the Bordeaux mixture the addition of a drop or two of this solution will cause a 
brownish-red color, and more lime should be added until no change takes place when 
the solution is dropped in. Use the Bordeaux mixture promptly, as it deteriorates on 
standing. 
Stock solutions of both the bluestone and lime may be kept for any length of 
time. Make the stock bluestone by dissolving in water at the rate of 2 pounds to 
the gallon. The stock hme is slacked and kept as a thick paste. Cover both mix- 
tures to prevent evaporation and keep the lime moist. For the 50-gallon formula 
add 3 gallons of the bluestone solution to 50 gallons of water, and introduce the stock 
lime slowly until there is no reaction with the testing solution.—B. T. G. 
— ae 
