3659. Stolba's Method of Nickel Plating

3659.      Stolba's Method of Nickel Plating. Into the plating vessel - which may bo of porcelain, but preferably of copper - is placed a concentrated solution of chloride of zinc, which is then diluted with from 1 to 2 volumes of water, and heated to boiling. If any precipitate separates, it is to bo redissolv-ed by adding a few drops of hydrochloric acid. As much powdered zinc as can bo taken on the point of a knife is thrown in, by which the vessel becomes covered internally with a coating of zinc. The nickel salt - for which purpose cither the chloride or sulphate may be used - is then added until the liquid is distinctly green; and the articles to bo plated, previously thoroughly cleaned, are introduced, together with some zinc fragments. The boiling is continued for 15 minutes, when the coating of nickel is completed, and the process is finished. The articles are well washed with water and cleaned with chalk. If a thicker coating bo desired, the operation may be repeated. Professor Stolba found that copper vessels thus plated were scarcely tarnished after several months' use in the laboratory.