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Gallic Acid

When pure, gallic Schlesinger gives the following method:

Sugar 4 parts (dried at 257° Fahr.); nitric acid (specific gravity 1.38) 33 parts; the mixture, as soon as the evolution of gas ceases, is to be boiled down to one-sixth its original less crystals, which have a beautiful silky volume, and allowed to crystallize. The whole process may be executed in 2 hours, pale yellow color, soluble in both water and and yields of beautifully crystallized oxalic acid from 56 to 60 per cent. of the sugar employed. lustre. Commercial gallic acid has usually a alcohol. Its aqueous solution decomposes by exposure to the air. It blackens the salts of a deep, rich, red solution, which, when thrown iron. Dissolved in hot oil of vitriol, it forms into water, drops the gallic acid, deprived of some of its water. Gallic acid forms GAL- On the large scale, the first part of the process is usually conducted in salt-glazed stoneware pipkins, about two-thirds filled and set in a water-bath; but on the small scale a LATES with the bases. glass retort or capsule may be used. The 3906. Το Obtain Gallic Acid. Mix 36 evaporation should be preferably conducted | troy ounces nut-gall, in fine powder, with sufficient distilled water to make a thin paste; its bulk of water, to form again a soft paste, expose the mixture to the air in a shallow and express as before. Mix the liquids, and glass or porcelain vessel, in a warm place, for evaporate spontaneously to a syrupy consista month, occasionally stirring with a glass ence; then spread it on glass or tinned rod, and adding sufficient distilled water to preserve the original consistence. Then press out the water, boil the residue in 8 pints dis- A plates, and dry quickly in a drying closet.

Put the dry residue in a well-stopped bottle.