ials can be reproduced--there is no advantage
in quoting them here.

CHAPTER IV

ELECTROPLATING AND ALLIED ARTS

Sec. 127. Electroplating.

This is an art which is usually deemed worthy of a treatise to itself,
but for ordinary laboratory purposes it is a very simple matter--so
simple, indeed, that the multiplicity of receipts as given in
treatises are rather a source of embarrassment than otherwise.

The fundamental principles of the art are:-

(1) Dirty work cannot be electroplated.

(2) Electroplated surfaces may be rougher, but will not be smoother
than the original unplated surface.

(3) The art of electroplating being in advance of the science, it is
necessary to be careful as to carrying out instructions in detail.
This particularly applies to the conditions which determine whether a
metallic deposit shall come down in a reguline or in a crystalline
manner.

Sec. 128. The Dipping Bath.

An acid dipping bath is one of the most useful adjuncts to the
laboratory, not only for cleansing metals for electroplating, but for
cleaning up apparatus made out of bits of brass tube and sheet, and
particularly for quickly cleaning binding screws, etc, where it is
necessary to ensure good electrical contact.

The cheapest and most satisfactory way in the end is to make up two or
three rather large baths to begin with. The glass boxes of storage
batteries do very nicely for the purpose, and being generally ground
pretty flat at the top, they may be covered by sheets of patent plate
glass, and thus preserved from the action of the air.

First Bath. A 30 or 40 per cent solution of commercial caustic soda.
Objects may be cleansed from grease in this bath by heating them as
hot as is consistent with individual circumstances, and plunging them
into it.

It is a considerable advantage to begin by removing grease from
articles subsequently to be dipped in an acid bath, both because it
saves time and acid, and because more uniform results are obtainable
when this is done than when it is omitted. It is a great advantage to
have the caustic soda solution hot. This is always done in factories
where nickel-plating is carried on, but it is inconvenient in the
laboratory. The articles after dipping in the alkali are swilled with
water, and may even be scrubbed with a brush, so as to remove greasy
matters that have been softened but not entirely removed.

Acid Bath. A convenient bath for laboratory purposes is made by