Translated for the Scientific American Supplement by
Jenny H. Beach, from Neue Illustrirte Zeitung_.
* * * * *
ON NICKEL PLATING.
By THOMAS T.P. BRUCE WARREN.
The compound used principally for the electro-deposition of nickel is a
double sulphate of nickel and ammonia. The silvery appearance of the
deposit depends mainly on the purity of the salt as well as the anodes. The
condition of the bath, as to age, temperature, and degree of saturation,
position of anodes, strength of current, and other details of manipulation,
which require care, cleanliness, and experience, such as may be met with in
any intelligent workman fairly acquainted with his business, are easily
acquired.
In the present paper I shall deal principally with the chemical department
of this subject, and shall briefly introduce, where necessary, allusion to
the mechanical and electrical details connected with the process. At a
future time I shall be glad to enlarge upon this part of the subject, with
a view of making the article complete.
A short time ago nickel plating was nearly as expensive as silver plating.
This is explained by the fact that only a few people, at least in this
country, were expert in the mechanical portions of the process, and only a
very few chemists gave attention to the matter. To this must be added that
our text-books were fearfully deficient in information bearing on this
subject.
The salt used, and also the anodes, were originally introduced into this
country from America, and latterly from Germany. I am not aware of any
English manufacturer who makes a specialty in the way of anodes. This is a
matter on which we can hardly congratulate ourselves, as a well known
London firm some time ago supplied me with my first experimental anodes,
which were in every way very superior to the German or American
productions. Although the price paid per pound was greater, the plates
themselves were cheaper on account of their lesser thickness.
The texture of the inner portions of these foreign anodes would lead one to
infer that the metallurgy of nickel was very primitive. A good homogeneous
plate can be produced, still the spongy, rotten plates of foreign
manufacture were allowed the free run of our markets. The German plates
are, in my opinion, more compact than the American. A serious fault with
plates of earlier manufacture was their crumpled condition after a little
use. This involved
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