for the loss of its lime, bestows upon it an
unusual amount of heat; and the surrounding particles, not to be
outdone, make it almost unlimited presents of salt. Full to overflow
with the gifts of its new companions, it hastens to bestow of its
superabundance on less favoured particles; joins the great army of the
ocean's currents; enters, perchance, the Gulf of Mexico, where it is
turned back, and hastens along with the Gulf Stream, with all its
natural warmth of character, to ameliorate the climate of Great Britain
and the western shores of Europe. Having accomplished this benevolent
work, it passes on, with some of its heat and vigour still remaining, to
the arctic seas--where it is finally robbed of all its heat and nearly
all its salt, and frozen into an icicle--there for many a long day to
exert a chilling influence on the waters and the atmosphere around it.
Being melted at last by the hot sun of the short arctic summer, it
hurries back with the cold currents of the north to the genial regions
of the equator, in search of its lost caloric and salt, taking in a full
cargo of lime, etcetera, as it passes the mouths of rivers. Arrived at
its old starting-point, our wanderer receives once more heat and salt to
the full, parts with its lime, and at once hastens off on a new voyage
of usefulness--to give out of its superabundance in exchange for the
superabundance of others: thus quietly teaching man the lesson that the
true principles of commerce were carried out in the depths of the sea
ages before he discovered them and carried them into practice on its
surface.

Perchance another fate awaits this adventurous particle of water.
Mayhap, before it reaches the cold regions of the north, it is
evaporated into the clouds, and descends upon the earth in fresh and
refreshing rain or dew. Having fertilised the fields, it flows back to
its parent ocean, laden with a superabundant cargo of earthy substances,
which it soon parts with in exchange for salt. And thus on it goes,
round and round the world; down in the ocean's depths, up in the cloudy
sky, deep in the springs of earth; ever moving, ever active, never lost,
and always fulfilling the end for which it was created.

All ocean currents are composed of water in one or other of the
conditions just described;--the hot and salt waters of the equator,
flowing north to be cooled and freshened; the cold and fresh waters of
the north, flowing south to be heated and salted