n of the electrolyte.

The process of amalgamating the zinc may be performed by dipping it in
a solution composed of

Nitric Acid 1 lb.
Muriatic Acid 2 lbs.
Mercury 8 oz.

The acids should be first mixed and then the mercury slowly added
until dissolved. Clean the zinc with lye and then dip it in the
solution for a second or two. Rinse in clean water and rub with a
brush.

Another method of amalgamating zincs is to clean them by dipping them
in dilute sulphuric acid and then in mercury, allowing the surplus to
drain off.

Commercial zincs, for use in voltaic cells as now manufactured,
usually have about 4 per cent of mercury added to the molten zinc
before casting into the form of plates or rods.

Series and Multiple Connections. When a number of voltaic cells are
joined in series, the positive pole of one being connected to the
negative pole of the next one, and so on throughout the series, the
_electromotive forces_ of all the cells are added, and the
electromotive force of the group, therefore, becomes the sum of the
electromotive forces of the component cells. The currents through all
the cells in this case will be equal to that of one cell.

If the cells be joined in multiple, the positive poles all being
connected by one wire and the negative poles by another, then the
_currents_ of all the cells will be added while the electromotive
force of the combination remains the same as that of a single cell,
assuming all the cells to be alike in electromotive force.

Obviously combinations of these two arrangements may be made, as by
forming strings of cells connected in series, and connecting the
strings in multiple or parallel.

The term battery is frequently applied to a single voltaic cell, but
this term is more properly used to designate a plurality of cells
joined together in series, or in multiple, or in series multiple so as
to combine their actions in causing current to flow through an
external circuit. We may therefore refer to a battery of so many
cells. It has, however, become common, though technically improper, to
refer to a single cell as a battery, so that the term battery, as
indicating necessarily more than one cell, has largely lost its
significance.

Cells may be of two types, primary and secondary.

Primary cells are those consisting of electrodes of dissimilar
elements which, when placed in an electrolyte, become immediately
ready for ac