PARIS GREEN AS AN INSECTICIDE. 147 


~ Strength of the miature. 
Paris green does not dissolve in water: it is simply held in 
Suspension. The strength of the mixture depends on the 
quality of the foliage to be sprayed. The teak has a thick» 
tough leaf even when young, and the mixture of 1 lb. of Paris 
green to 150 gallons of water should be tried first. If it does 
not appear to kill off the larvee, it might be made stronger up to 
1 lb. of Paris green to 130 gallons of water. The lime or flour 
used has of course no effect: it is simply to enable the Paris 
green to mix better whilst at the same time the lime would take 
up any free arsenic. 
Method of mixing. 
The exact method of mixing is quite immaterial, only 
remember that the powder should be thoroughly diffused 
through the water, not allowed to be in lumps. The mixture 
must be kept an even strength throughout. The Paris green 
and lime should be first mixed up with a small quantity of 
water, and then the rest added till the full amount has been 
made up. The operator should not handle or inhale the 
powder. 
Applying the mixture. 
It should be applied as a fine spray by means of a force- 
pump. It should be thrown so finely as to reach all parts of 
the tree and both sides of the leaves, and coat the leaves as with 
a fine dew. The foliage must not be drenched, but the spray 
should only be allowed to fall upon the trees until it begins to 
drop from the leaves. All washes containing Paris green must 
be kept constantly stirred to keep it in suspension, or it will 
sink to the bottom. This is important, The following points 
should be insisted on :— 
(a2) As above mentioned, keep the mixture well stirred all 
the time. 
(4) Have the barrel or vessel used for the mixture well 
washed out after it has been filled ten or twelve 
times. The Paris green is very heavy and keeps 
sinking to the bottom. As the barrel is frequently 
refilled, the residue will keep accumulating until it 
will be too strong as the mixture reaches the bottom, 
L 2 
