Читать книгу Henley's Formulas, Recipes and Processes (Applied Chemistry) - Various - Страница 61

—I.—Make a paste of sulphur, sal ammoniac, iron filings, and boiled oil.

II.—Mix together dry: Whiting, 6 pounds; plaster of Paris, 3 pounds; sand, 3 pounds; litharge, 3 pounds; rosin, 1 pound. Make to a paste with copal varnish.

III.—Make a paste of boiled oil, 6 pounds; copal, 6 pounds; litharge, 2 pounds; white lead, 1 pound.

IV.—Make a paste with boiled oil, 3 pounds; brickdust 2 pounds; dry slaked lime, 1 pound.

V.—Dissolve 93 ounces of alum and 93 ounces of sugar of lead in water to concentration. Dissolve separately 152 ounces of gum arabic in 25 gallons of water, and then stir in 62 ¹/₂ pounds of flour. Then heat to a uniform paste with the metallic salts, but take care not to boil the mass.

VI.—For Iron and Marble to Stand in Heat.—In 3 pounds of water dissolve first, 1 pound water glass and then 1 pound of borax. With the solution make 2 pounds of clay and 1 pound of barytes, first mixed dry, to a paste.

VII.—Glue to Resist Boiling Water.—Dissolve separately in water 55 pounds of glue and a mixture of 40 pounds of bichromate and 5 pounds of alum. Mix as wanted.

VIII. (Chinese Glue).—Dissolve shellac in 10 times its weight of ammonia.

IX.—Make a paste of 40 ounces of dry slaked lime 10 ounces of alum, and 50 ounces of white of egg.

X.—	Alcohol	1,000 parts
Sandarac	60 parts
Mastic	60 parts
Turpentine oil	60 parts

Dissolve the gums in the alcohol and add the oil and stir in. Now prepare a solution of equal parts of glue and isinglass, by soaking 125 parts of each in cold water until it becomes saturated, pouring and pressing off the residue, and melting on the water bath. This should produce a volume of glue nearly equal to that of the solution of gums. The latter should, in the meantime, have been cautiously raised to the boiling point on the water bath, and then mixed with the hot glue solution.

It is said that articles united with this substance will stand the strain of cold water for an unlimited time, and it takes hot water even a long time to affect it. {22}

XI.—	Burgundy pitch	6 parts
Gutta percha	1 part
Pumice stone, in fine powder	3 parts

Melt the gutta percha very carefully add the pumice stone, and lastly the pitch, and stir until homogeneous.

Use while still hot. This cement will withstand water and dilute mineral acids.