_The current_ is that moving electric essence which traverses the
circuit. The _course_ of the current is always from the positive to the
negative. It leaves the machine at the positive post, where it enters
the cord which holds the positive electrode or pole. Thence it advances
around the circuit, going out from the opposite cord where that connects
with the negative post. The forward end of the current is its positive
end; the rear, of course, is its negative end. At its forward end it is
in its greatest volume. At its rear end the volume is least. At the
_central point_ of its circuit there is the _mean_ quantity--the
_average_ volume. And because the positive and negative forces on either
side exactly balance each other upon the central point, therefore this
point is practically neuter--neither positive nor negative.