THE 
GARDEN YARD 232 
of arsenic or of kerosene emulsion, and occasion- 
ally whale-oil soap is used. The most common 
form of arsenical poison is Paris green, of which 
about 2000 tons are used annually in this 
country ; this is mixed in the proportion of one- 
half pound of Paris green to 100 to 150 gallons 
of water and one-half pound of fresh burnt lime. 
However, where the insects are very bad, 
as potato bugs often are, the same amounts of 
Paris green and lime may be mixed with only 
50 gallons of water. Paris green is too caustic 
to apply stronger than that, except in very 
rare, specified cases. The Paris green should 
be mixed with a little water till it is smooth, 
before it is added to the larger quantity of water. 
Sometimes it can be sprinkled on, but the only 
sure results are secured by using a spray, either 
hand or power. 
Sometimes Paris green is added to the Bor- 
deaux mixture, and the crops sprayed for in- 
sects and diseases at the same time. When 
this is done, you regard the Bordeaux as water, 
and add the Paris green in the same propor- 
tion as you would add it to water. In this 
case you need not add the lime, because the 
lime in the mixture is sufficient. London 
purple is sometimes used in place of Paris green 
for the same purposes, and in exactly the same 
