Or 5 ounces of tannin, 5 ounces of gallic acid, ounces of copperas, 1 ounce of indigo, carmine, or aniline blue, and 20 drops of sulphuric acid; or, for smaller quantities, the same proportions by weight. This mixture will be found an excellent ink for schools, offices, and domestic pur poses.
The following recipes will suggest interesting experiments in ink mak ing: pulverized Aleppo galls, 3 pounds; gum arabic, 1 pound. Put these in an earthen jar and add 1 gallon of boiling water. Let stand in a warm place for 2 weeks, stir ring frequently. Add 1 pound of green copperas dissolved in pints of water. Mix and let stand 2 or 3 weeks, stirring daily. The addition of 4 ounces of aniline blue and 2 ounces of sulphuric acid will improve this mixture.
Or mix 2 ounces of crushed gall nuts, 1 ounce of gum arabic, and 1 ounce of copperas with 16 ounces of soft water. Add 5 grains of corro sive sublimate to prevent mold. Let stand for 2 weeks, shaking frequently, before using.
A solution of logwood is often add ed to the nutgall inks to give a strong er black. Cover pound of Aleppo bruised galls with 1 gallon of soft water; let stand 3 weeks, stirring daily. Add 4 ounces of green cop peras dissolved in 1 pint of water, 4 ounces of logwood chips, 6 ounces of gum arabic, and 2 ounces of alcohol. Stir, and let stand a week or 10 days before using.
Mix 4 ounces of bruised Aleppo galls, 2 ounces of thin logwood chips, and 3 quarts of soft water; boil down to 3 pints. Add 2 ounces of green copperas, 1 ounces of powdered gum arabic, ounce of blue vitriol, and ounce of brown sugar. Stir until dissolved, let stand 24 hours, strain, and bottle for use.
Or mix 1 ounce of powdered cop peras, 1 ounce of fine logwood chips, 3 ounces of crushed Aleppo galls, 1 ounce of gum arabic, and 6i pounds of white wine or best vinegar.
Or boil 4 ounces of logwood chips in 6 quarts of water down to 3 quarts. Strain, and add 2 quarts of cold water. Add to this solution 1 pound of bruised Aleppo galls, 4 ounces of sulphate of iron, and ounce of ace tate of copper. Rub to a smooth paste with a little of the logwood liquor. Add also 3 ounces of coarse sugar and 6 ounces of gum arabic.
Chrome Logwood Inks.—These inks are prepared by the addition of 1 part of potassium chromate to 1,000 parts of saturated solution of log whod. Or boil the solution of log wood with chloride or acetate of chromium. Inks of this class have no sediment, do not corrode steel pens, and do not turn moldy. Writing
done with them may be soaked in water without the ink running or washing off. They also have the ad vantage over iron-gall inks that they will not fade.
To make chrome logwood ink on a large scale, boil 22 pounds of logwood in PS gallons of water down to 14 gallons; when cold, to 1,000 parts of this infusion add gradually 1 part of yellow chromate of potash, stirring constantly.
Or, for a small quantity, boil 1i ounces of thin logwood chips in 3 pints of water down to 1 pint, and when cold add 17 grains of yellow chromate of potash, stirring thor oughly. Do not add gum or acid. To prevent mold, add a few drops of bi chloride of mercury.
Copying Inks. — Copying inks are of the same composition as ordinary writing inks, but thicker. Gum, sugar, and other sticky ingredients are used in copying inks to keep them from soaking into the paper before it is brought in contact with the moist tissue paper of the copying press. The largest number of copies from one writing is obtained by means of a strong decoction of logwood extract with alum or chloride of aluminum, and by the use of sheets of tissue copying paper previously soaked in chromate of potash. A small amount of the logwood solution unites with the chromate salt in the tissue paper to form a black compound.
Or put 1 pound of powdered Alep po galls in an earthen jar and cover with 2 gallons of rain water. Let stand 10 days. Add 4 ounces of clean copperas, 4 ounces of brown sugar, and 4 ounces of gum arabic dissolved with gentle heat in a little water. Put the whole in an iron ket tle and boil down to 1 gallon.
Or put 2 ounces of logwood ex tract, 4 ounces of sal soda, and IS ounces of soft water in an earthen vessel, and set it in the oven until the solution becomes a deep red and the ingredients are all dissolved. Remove from the oven, and stir in 2 ounces of glycerin, 30 grains of yellow chromate of potash dissolved in a lit tle water, and ounce of gum arabic dissolved in water. Strain through cheese cloth and boil down to one half with gentle heat.
Or add 1 teaspoonful of brown sugar to 1 pint of ordinary writing ink. To take a single copy from any of the above without a copying press, first let the ink dry, then moisten a sheet of tissue paper or unsized writ ing paper with water, but do not have it too wet. Lay it over the writing, and go over it with a warm flatiron.