ying with force and in
the form of a fine rain or mist, water in which a poison or a
substance which kills by contact is suspended. The first application
of the principle was against chewing insects with hellebore. Pure
arsenic was early used and soon led to the use of other arsenicals.

Our greatest fungicide, Bordeaux mixture, was discovered by accident
in 1882 when it was found to control mildew in France. Up until about
five years ago Bordeaux mixture as the fungicide and paris green as
the poison were almost universally used. Within the last few years,
however, there have been developed two substitutes which, although
known and used to some extent for twenty years, have only recently
come into such general use as practically to replace the old sprays.
These are lime and sulphur as the fungicide and partial insecticide
and arsenate of lead as a partial insecticide.

The necessity for and the advisability of spraying have already been
pointed out. There is an increasing demand for fine fruit the
supplying of which is possible only with thorough spraying. In the
humid East especially the competition of more progressive sections in
the West is demanding more and better spraying. There is no cure-all
in this process. It does not make a tree more fruitful except as it
improves its general health, but it does bring a larger percentage of
the fruit to perfection. Certain knowledge is fundamental; the grower
must know what he is spraying for, when and with what to combat it and
how to accomplish the desired result most effectively.

Spraying is an insurance against anticipated troubles with the fruit,
and the best and most successful growers are those most completely
insured. It has many general advantages also. It stimulates the grower
to a greater interest in his business because of the extra knowledge
and skill required. It compels thoroughness. It necessitates spending
money, therefore a return is looked for. To be sure, it is only one
of the operations necessary to success, but it enables us to grow a
quality of fruit which we could not obtain without it.

SPRAY MATERIALS are conveniently divided into two classes,
insecticides and fungicides. An insecticide is a poison by which the
insect is killed either directly by eating it, or indirectly by the
caustic, smothering, or stifling effects resulting from closing its
breathing pores. Direct poisons are used for insects which eat some
part of the tree or fruit and are