Answer.—Electro-plating is a process that requires apparatus, and a degree of skill in using the same which render it scarcely worth while to enter into a detailed description of it. We outlined the process not long ago, and cannot reiterate it. A cheap and simple method of silvering metals, that any one can put in practice, is as follows:
Clean the articles to be silvered with nitric acid, rub them with a mixture of cyanide of potassium and powdered silver, and wash thoroughly in clear, warm water. Then plunge them into a liquor composed of two parts, by weight, of grape sugar or sugar of milk, two of gallic acid, and 650 parts of distilled water, filtered and kept from the air in tightly-corked bottles until the instant of use. After a few minutes take them out of this liquor and immerse them in another composed of twenty parts, by weight, of nitrate of silver, twenty parts of ammonia solution, and 650 parts of distilled water. Repeat this process, plunging the articles first into one liquor and then into the other, every few minutes, until they are all well coated. The process can be accelerated by heating either the mixture or the articles to a moderate degree. Some persons prefer to mix the two liquors at the moment of use in equal quantities. In such case, shake the mixture thoroughly and filter before immersing the metals. The ammonia solution should be of standard strength. If there is any doubt of this, dissolve the nitrate of silver for the second liquor in the distilled water, add the first liquor, mix thoroughly, and add only enough ammonia to clear the mixture. This is the process for copper, brass, German silver, and similar articles, but before silvering iron or steel they should be coated with copper by leaving them for a little time in a solution of sulphate of copper.
THE GUILLOTINE.
Fairmont, Neb.
I should like to know who was the inventor of the guillotine. How was it constructed and operated.
W. P. Jacks.
Answer.—For many years the invention of the guillotine, the instrument for inflicting capital punishment adopted by the French during the reign of terror, was accredited to Joseph Ignace Guillotine, a French physician, born in 1738, who in 1785 recommended its use in France from motives of humanity, in place of the barbarous gibbet. However, there is in the Antiquarian Museum of Edinburgh a guillotine made before 1581, which served to behead the Scottish Regent, Morton, who had introduced it into use in that country. It was used in Italy in the thirteenth century in a form resembling the instrument now used in France. The guillotine is composed of two upright beams, grooved upon the inside, and surmounted by a cross-beam. Between these beams and sliding in the grooves is a sharp, iron blade, which falls by its own weight with great speed and certainty, severing the head from the body.
ASSESSMENT OF DEPOSITS.