7 
The arsenite of lead is prepared by carefully pulverizing and com- 
bining, in a small quantity of water, the weight of the two ingredients 
needed at the strength decided upon as indicated by the capacity of 
the spray tank. The chemical combination is effected in a few minutes 
and the resulting milky mixture is ready for the tank. Lime is not 
needed with this arsenical. At slightly greater expense this arsenical 
can be procured already combined as a dry powder, white or colored 
with a dye. 
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 being greatly intensified in the mixture. 
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 
long and about 2 inches in diameter is taken, and a three fou. ...s inch 
hole bored through it within 6 inches of each end. Near each end is 
securely tacked a bag of ‘8-ounce osnaburg cloth,” 1 foot wide and 18 
inches to 2 feet long, so that the powdered poison may be introduced 
into the bags with a funnel through the holes at the ends of the pole. 
The bags are filled with undiluted Paris green, which is generally pre- 
ferred to London purple on account of its quicker action, and the appa- 
ratus is carried on horse or mule back, through the cotton fields, 
dusting two or four rows at once. The shaking induced by the motion 
of the animal going at a brisk walk or at a trot is sufficient to dust the 
1 Bordeaux mixture formula.—tinto a 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 lime 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.—GALLOoway. 

