A kind of mineral, of a strong, sharp taste. It dissolves both in cold and boiling water, but best in the latter. It is of some use in medicine; a principal ingredient in dyeing and coloring, neither of which can be well performed without it, as it sets and brightens the colors, and prevents them from washing out. It is also extremely useful in many arts and manufactures. Are there not different sorts of this material? The principal kinds are native alums: _viz._ those prepared and perfected underground by the spontaneous operations of nature; as the roch, commonly called rock alum, from Rocha, in Syria, whence it is brought. _Spontaneous_, unassisted by art. _Orientals_, inhabitants of the Eastern parts of the world. What is Ink? A liquor used in writing on paper or parchment, made of copperas, galls; and gum arabic[6] mixed together. There are likewise several plants that may serve for the making of ink, as oak-bark, red roses, log-wood, &c. It is also made from an infusion of oak galls and iron filings: there are also many other ways, as well as materials, employed in the making of this useful article. Ink is the name applied to all liquids used in writing, of whatever color they may be, as red, blue, &c., though black is the most used for common purposes. The ink of the ancients seems to have been of a thick, oily nature, unlike the modern ink; it consisted of nothing more than a species of soot, or ivory black, mixed with one fourth of gum. [Footnote 6: See Chapter XI.] What is Copperas? A kind of vitriol. Copperas is the name given to green vitriol, which is a preparation from iron. The blue vitriol is a sulphate of copper, and the white vitriol a sulphate of zinc. For what is Vitriol used? In the making of glass, to color it; in many arts and manufactures; and in medicine. What are Galls? Excrescences formed on a kind of oak tree in certain warm climates; perforations are made by an insect into the bark of the tree, whence issues a liquid which hardens by exposure. They are used in dyeing, making ink, and other compositions. There are two sorts of oak galls in our shops, brought from the Levant, and the southern parts of Europe. What does the word Levant signify? A country to the eastward. It is applied to the countries of Turkey, Greece, Asia Minor, Syria, Egypt, &c., which are washed by the eastern part of the Mediterranean. Is the Ink used in Printing the same as writing Ink? No; it is more of the nature of paint, being thicker and more glutinous: it chiefly consists of a mixture of oil and lamp-black, or some other ingredient, according to the color required; and is remarkable for the ease with which it adheres to paper that is moistened. _Glutinous_, gummy, resembling glue. What is Indian, or Chinese Ink?