he other post to the
foot-electrode, between eight and nine feet. The distal ends of the
wires should be stripped of their coating for a length of about three
inches, the proximal ends for about two inches. The denuded portion of
the distal ends should be rolled up in the form of a spiral coil; this
will insure their constant impinging on the carbons more certainly than
could be expected from a simple straight end of wire.

The carbons having now been fitted in their beds, the distal end (coil)
of the head wire is placed beneath the carbon, and the wire itself
continued up along the vertical groove to either one of the gimlet
holes. Through this, from within outward, the proximal end of the wire
is now drawn and left for the present. The distal end of the second wire
having now been placed beneath the carbon at the foot of the tub, this
wire is continued up through the vertical groove, along the upper edge
of the foot of the tub to the side nearest the binding post to which the
wire is to be attached, along the groove on the upper edge of this side
to the head of the tub, and thence to the respective gimlet hole, and
through this, from within outward. The wires being now all in position,
all the coping is next screwed or nailed down firmly, care being taken
that the screws or nails used for this purpose do not injure any of the
wires. The coping fastened down, the binding posts are now screwed down
in the sites previously marked out for them. Before they are screwed
_entirely_ down, the denuded portion of the proximal end of each wire is
securely wound around the screw of the respective binding post, and the
posts are then _firmly_ screwed down, holding the proximal ends of the
wires in place. Connection is now established between the binding posts
and the head and foot electrodes respectively. The vertical grooves are
now to be filled in with putty and painted over, care being taken to
keep the carbon free from paint. The last step towards completing the
apparatus is to fasten the carbons in their beds. The simplest way of
doing this is by stretching over each carbon a piece of muslin, folded
double, and tacking this down around the edges. Zinc or galvanized iron
tacks are best. Copper tacks should be avoided on account of their
superior conductivity.

In order to be able when required to localize the current in special
portions of the body, it is well to be provided with what I have termed
a "surface board." This is