es,
high chimneys, spires, in fact all points elevated above the earth's
surface assist greatly in charging and discharging the atmosphere.
Again, if two iron rods are driven into the earth and connected by a
copper wire with an electrometer in the circuit, the instrument is
almost immediately affected, showing that currents of electricity are
running through the ground. Now, what is the function of these
atmospheric and ground electric currents? Many scientists are agreed
that certain forms of precipitation are due to electrical action; but
my observations have led me to believe conclusively that electricity
is a potent factor in the economy of nature, and has more to do with
the growth and development of plants than has hitherto been known.
Davy succeeded in the decomposition of the alkalies, potash and soda,
by means of electric currents. In our laboratories, water and ternary
compounds are rapidly decomposed by the battery, and we may reasonably
suppose that that which is effected in our laboratories by artificial
means takes place in the great laboratory of nature on a grander and
more extended scale.

Plant food is carried throughout the plant by means of the flow of
sap; these currents circulate through all the rootlets and center, as
it were, in the stalk, carrying their tiny burdens of various elements
and depositing them in their proper places. That this phenomenon of
circulation is due to electricity cannot be doubted. Most plants grow
more rapidly during the night than in the day. May not the following
be a reason for this?

We have already mentioned how electric currents pass from air to earth
and _vice versa_; at night the plant is generally covered with dew and
the plant itself becomes a good conductor, and, consequently, currents
of electricity pass to each through this medium, and during the
passage convert soil elements into plant food and stimulate the upward
currents to gather up the dissolved elements and carry them to their
proper places.

From the time electricity became a science, much research has been
made to determine its effect, if any, upon plant growth. The earlier
investigations gave in many cases contradictory results. Whether this
was due to a lack of knowledge of the science on the part of the one
performing the experiments, or some defect in the technical
applications, we are not prepared to say; but this we do know, that
such men as Jolabert, Nollet, Mainbray and other eminent phy