Page:Popular Science Monthly Volume 25.djvu/583

Rh by the success which Mr. Joseph Wharton has attained in the production of metallic nickel of suitable purity at a reasonable price. Mr. Wharton was one of the first to work the metal successfully, and exhibited at Vienna, in 1873, samples of axles and axle-bearings, and at Philadelphia, in 1876, a remarkable series of objects of wrought-nickel. He produced in his works, between 1876 and the close of 1882, 1,466,765 pounds of the metal, the principal source of supply of which was from the ores at Lancaster Gap, Pennsylvania. The earliest practical process for nickel-plating in the United States was patented by Isaac Adams, Jr., in 1869. He devised a bath of the double sulphate of nickel and ammonium and the double chloride of nickel and ammonium, with anodes of metallic nickel, in which iron was combined, to obviate the bad effects of copper and arsenic impurities. The extensive application of this process was facilitated by the production of nickel of improved qualities of purity, and the introduction of dynamos for producing the electric currents, they taking the place of the expensive galvanic battery. Edward Weston, in 1878, prepared a solution containing boric acid, with the double sulphate of nickel and ammonium, the superiority of which is generally recognized. The deposited metal is almost silver-white, dense, homogeneous, and tenacious, while the solution maintains a uniform, excellent working quality. Among other solutions which have been introduced, one prepared by adding ammonia and water to the sulphate of nickel, is recommended by Professor Böttger, and is said to be well suited for the purposes of amateurs, because of its giving good results with a platinum anode. Compositions containing sulphate of nickel and ammonium and sulphate of ammonium are recommended for coating several different metals. Where the double sulphate of nickel and ammonium is used, the bath should be maintained as nearly neutral as possible; but it may be either slightly acid or slightly alkaline. The strength of the current should be carefully regulated according to the surface of the articles in the bath, or the work will be apt to "burn," when the metal is precipitated as a dark-gray or black deposit. To obviate this difficulty, a plate of nickel presenting considerable surface is suspended from the rods by which the objects to be plated are held in the bath, to divert the surplus of the current from them. Other things being equal, the slower the rate of deposition, the more adherent and tenacious the coating of deposited metal will be. Success in plating depends very largely upon the perfect cleansing of the articles before they are immersed in the bath; and this is more important in case of plating with nickel than with other metals, for which the solutions are generally more alkaline. As nickel-plated articles can not be burnished on account of the hardness of the deposited metal, they should be thoroughly polished before being exposed to the bath. A good coating of nickel properly laid on preserves great durability.

A People who can not make Fire.—The Papuans of the Maclay coast of New Guinea are represented by the Russian explorer, Dr. Miklucho Maclay, as being in the most primitive stage. They are wholly unacquainted with metals, and make their weapons of stone, bones, and wood. They do not know how to start a fire, though fire is in use among them. When the traveler asked them how they made a fire, they could not understand his question, but they regarded it as very amusing, and answered that when a person's fire went out he got some of a neighbor, and, if all the fires in the village should go out, they would get it from the next village. Some of the natives represented that their fathers and grandfathers had told them that they remembered a time, or had heard from their ancestors that there was a time, when fire was not known, and everything was eaten raw. The natives of the southern coast of New Guinea, having no iron, shave themselves now with a piece of glass. Formerly they shaved with flint, which they could sharpen quite well, and used with considerable dexterity.

The Art of Early Rising.—The proper time to rise, says the "Lancet," is when sleep ends. Dozing should not be allowed. True sleep is the aggregate of sleeps, or is a state consisting in the sleeping or rest of all the several parts of the organism. Sometimes one and at other times another part of the body, as a whole, may