After making durable ink, set the marking liquid or lunar caustic preparation for three or four days in the hot sun; otherwise it will not become black.
SUMACH INK.—The milk or gum that exudes from the sumach is a good substitute for durable ink. Break off the stalks that support the leaves. Squeeze them into a cup, and write with the liquid. Expose it to the sun and it will become a fine black.
VERY FINE INK.—Into a large jar or pitcher put half a pound of the best Aleppo galls, broken up with a hammer or flat-iron; but not pounded. Pour on two quarts of soft water, nearly of boiling heat. Cover the vessel; and let it stand on a warm hearth or in the hot sun for a fortnight; stirring it to the bottom twice a day, with a stick. At the end of the fortnight, add two ounces of green copperas; two ounces of logwood chips; two ounces of gum-arabic; half an ounce of alum; and half an ounce of sugar-candy. Let the whole remain in a moderate heat a fortnight longer; stirring it twice a day. Keep the mouth of the vessel covered with paper only, tied down over it. On the last day, do not stir it, but pour the ink through a strainer into another vessel, and then with a funnel transfer it to bottles. Pour a small tea-spoonful or more of brandy into the top of each bottle, if small. To a pint bottle there should be a table-spoonful of brandy. This will preserve the ink from moulding. Cork the bottles well, and seal the corks. Keep them in a place of temperate heat.
In buying Aleppo galls get those that are dark coloured, heavy, and free from holes.
GOOD INK.—Bruise two ounces of Aleppo galls; put them into a pitcher with half an ounce of copperas, and a quarter of an ounce of gum arabic. Pour on a pint of soft water at boiling heat. Cover it, and let it stand a week; stirring it several times a day, except on the last day. Then pour it through a funnel into a bottle that has half a dozen cloves in it. In pouring, see that you do not disturb the sediment at the bottom of the pitcher. Cork the bottle tightly.