This section is from the "Henley's Twentieth Century Formulas Recipes Processes" encyclopedia, by Norman W. Henley and others.
Pure nickel will remain nearly white, while "patent nickel," or nickel-copper will not retain its primitive brilliancy, but soon becomes slightly oxidized and grayish in color. The magnet furnishes a good means of testing. The unadulterated nickel is distinctly sensitive to magnetism, while that much alloyed is destitute of this property.
See Cleaning Preparations and Methods.
NICKELING, TEST FOR: See Plating.