Stránka:roll 1931.djvu/128

112 Woodcraft Birch Bark Roll the stone; for there is little doubt that stone, sand, and ashes preceded file and paper in the shop of the Indian smith.” Oxydizing Oxydization gives a very finished effect to jewelry. To oxydize, place a piece of liver of sulphur in a pint of hot water, drop the bracelet in, and it will turn black. Re- move from solution, and with a little pumice and water, take off as much oxydization as desired. It is advisable to use the oxidizing liquid as soon as pre- pared. After it has been used for some time, the deposit be- comes dull and gray, and lacking in adherence. By dipping the oxydized article in a liquid composed of 10 parts of blue vitriol, 5 of sal-ammoniac, and Ioo of vinegar, the places of the silver left bright acquire a warm, brown shade. Another method of oxydization is effected by dipping the article in diluted chlorine water, in chloride of lime solution, or in eau de Javelle. The action of these baths is based upon the formation of a thin layer of silver chloride which becomes dark on exposure to light. Soldering Soldering should be practiced on scrap silver before being tried on a finished article. Place in a saucer a piece of borax the size of a hickory nut, and add enough water to make a milky solution. With a brush, apply this solution at the necessary points of contact around the design. It is not necessary that the whole design be soldered. | Cut small pieces of silver solder (1/16 x 1/16 inch), and drop on the borax solution saucer. Place these pieces, one at z. time, about the design, being sure that they always touch the silver ; and that, at these particular points, the design and foundation also touch each other, because metal must be touching in order to fuse in soldering. Carefully apply the heat with a blow pipe, slowly at first until the borax solution evaporates, heating the surrounding silver quite hot before applying the flame to the solder itself. Watch attentively for the solder to flow, then remove flame at once. The secret of good soldering is to keep the flame continually in motion, so as not to melt or burn the silver.