6348. To Clean Gutta-Percha

6348.    To Clean Gutta-Percha. This can be done by using a mixture of soap and powdered charcoal, polishing afterwards with a dry cloth with a little of the charcoal on it.

6349. To Dye Straw Hats Black

6349.    To Dye Straw Hats Black. The following is given as a black color for straw hats. The quantities of material are intended for 25 hats or bonnets. They are kept for 2 hours in a boiling decoction of 4 pounds logwood, 1 pound sumach, and 5 ounces fustic; and afterwards dipped into a solution of nitrate of iron of 4° Baumé, then well rinsed with water, and, when dry, are painted over with a solution of lac or dextrine.

6350. To Dye Leather Yellow

6350.    To Dye Leather Yellow. Pic-iic acid gives a good yellow without any mordant; it must be used in very dilute solution, and not warmer than 70° Fahr., so as not to penetrate the leather.

6351. To Dye Leather Green

6351.    To Dye Leather Green. Aniline blue modifies picric acid to a fine green. In dyeing the leather, the temperature of 85° Fahr. must never be exceeded.

6352. To Dye Leather Green

6352. To Dye Leather Green. Aniline green is well adapted to dyeing leather, and its application is quite simple. "Whether used in paste or as powder, we must make a concentrated aqueous solution. The leather is brushed over with a solution of sulphate of ammonia, mixed with water, the dye solution applied at 95° Fahr., and it must be endeavored, by rapid manipulation, to prevent the dye from penetrating through the leather. By the addition of picric acid, the blueish shade of this dye-stuff is modified to leaf green, and it becomes faster; but the picric acid must not be added to the color solution; it must be applied to the leather before or after the dyeing with aniline green. (Spring-muhl.)

6353. Slating for Black-Boards

6353. Slating for Black-Boards. The imitations of slate are of two kinds, real imitations, consisting of pulverized slate or quartz rock moistened to the consistency of a thick fluid with silicate of soda (water-glass of commerce), and applied to the boards by means of a brush; or merely paints, such as asphaltum or Grahamite dissolved in petroleum naphtha. The first one will produce slates that are very similar to the natural elates, less expensive than those, and last a good while.

6354. Asphalt for Walks

6354.    Asphalt for Walks. Take 2 parts very dry lime rubbish, and 1 part coal-ashes, also very dry, and both sifted fine. In a dry place, on a dry day, mix them, and leave a hole in the middle of the heap, as bricklayers do when making mortar. Into this pour boiling hot coal-tar; mix, and when as stiff as mortar put it 3 inches thick where the walk is to be; the ground should be dry, and beaten smooth. Sprinkle over it coarse sand. When cold, pass a light roller over it; in a few days the walk will be solid and waterproof.