80 
is applied with great force, the stream is broken up into a fine mist, 
which, if well directed, is evenly distributed over the foliage and fruit, 
and upon dr3dng leaves a more or less uniform coat. If the nozzle is 
held close to the foliage, the force causes it to spread well, but the 
coating is not so uniform as that which is derived from the mist. In 
spra^^ing one-half of a tree the mist drifts through the tree from the 
side which is being sprayed, and in that way the tree is well covered, 
having received practically two incomplete sprayings. If fruit is 
allowed to grow in clusters it is necessary to apply the spray with 
great force in order to secure good results. 
MATERIALS FOR SPRAYING. 
CONTACT INSECTICIDES. 
Contact insecticides are those which kill the insects by touching 
them. Kerosene emulsion and solutions of whale-oil soap are the sub- 
stances that have been most used for this purpose; but on account of 
the expense, the necessity of frequent application, and the fact that 
the insect can be more easil}^ and effectively reached in other stages by 
other insecticides, these kinds of spraying solutions have been used 
but little against the insect. 
AESENICAL SPRAYS. 
The arsenical spra3\s contain arsenic as their essential ingredient. 
Other chemicals are mixed with the arsenic for the purpose of pre- 
venting it from burning the foliage or are products incidental to the 
numerous compounds of arsenic which were used for other purposes 
than spraj^ng. There are man}^ spraying compounds of which arsenic 
is the base on the market, but there are many others which the fruit 
grower can make for himself by combining the necessary ingredients. 
Paris green is probabh^ the best known of these arsenicals. It has 
been used for man}' 3'ears with success, and is a definite chemical com- 
pound of arsenic, copper, and acetic acid. The composition is usuallj^ 
quite uniform, but many instances have been found in which it was 
adulterated or the percentage of soluble arsenic was dangerously high. 
As indicated b}^ its name, it is a substance green in color. It is a 
rather coarse powder, which has the fault of settling rapidly in the 
spraying tank. It is quite necessary to use lime with Paris green in 
order to counteract the burning effects of the free arsenic. Paris 
green is comparativeh^ expensive; in the East it costs about 20 cents a 
pound and in the West 25 cents. 
Paris green may be prepared for spraying as follows: 
Paris green . - pound. . 1 
Lime pounds . . 1 to 2 
Water gallons. . 100 to 250 
