INKS, are fluid compositions designed for writing, drawing, and printing. As there are a great variety of sorts, we shall treat them consecutively, according to the following arrangement of the subject, For Writing. 1. On black writing inks generally. 2. On common black writing ink. 3. On best, or Japan ink. 4. Copying ink. 5. Indelible, or indestructible ink. 6. Red ink. 7. Indestructible red ink. 8. Blue ink. 9. Yellow ink. 10. Green, and other coloured inks. 11. Cloth-marking ink. 12. Sympathetic, invisible, or secret inks. 13. Lithographic ink.
For Drawing. 14. Indian, and imitation Indian ink. 15. Lithographic ink, for drawing on atone or paper.
For Printing. 19. Letter-press printing ink. 17. Red, and other coloured ditto. 18. Copper-plate printing ink. 19. Lithographic printing ink.
For removing stains of ink, 20.
1. Black Writing Inks generallg.—When any vegetable matter, containing the gallic acid, is infused with a solution of iron in water, the gallic acid unites with the iron, and a black liquor results, from which the colour, in the form of an impalpable powder, is gradually precipitated. To prevent the latter effect, it becomes necessary to render the liquor viscid, or of greater specific gravity; and this is best effected by the addition of a gum which is perfectly soluble in water, as this gum, besides keeping the black fecuhe suspended in the liquor, serves also to prevent the ink from sinking or spreading on the paper, and likewise to defend it, in the manner of a varnish, from the action of the air. Ink may therefore be regarded as merely a gallate of iron, combined with a little mucilage. It follows, from this view of the matter, that the same, or very nearly the same, kind of black liquid may be produced from a great variety of substances, and, therefore, to make 2. Common Black Writing Ink.—It becomes the business of the manufacturer to select such materials as will produce the required quality at the least cost to himself. It is commonly supposed that nut-galls are employed on a large scale for this purpose, but the low price at which common ink is sometimes sold per gallon, renders this improbable ; and that such an expensive material (however good) is not necessary, the reader has only to consider that the dyer makes a variety of good blacks without it. Of all known vegetable matters,
sumach approaches nearest to galls, and forms a very cheap substitute ; com bined with the sulphate of iron (green copperas) it makes a very rich black ink, but it requires some peculiar management to prevent its becoming thick. Logwood, from the great affinity of its colouring matter to the oxide of iron, renders it a most desirable substitute for galls. It is well known to be partially used with galls in making ink ; but very good common ink may be made from it without any other astringent matter. Valonia, the barks of the oak, chestnut, and many other trees, may be very advantageously applied as useful substitutes for galls in making common ink, and are well deserving of the attention of the manufacturer who may not be acquainted with their properties. A good common ink is made in the following manner : Take 8 ounces of Aleppo galls, in coarse powder, and 8 ounces of logwood, in thin chips; boil these in six quarts of soft water for an hour, and supply the waste from evaporation by the addition of fresh water; strain the decoction through a hair sieve, and then add 5 ounces of sulphate of iron, and 3 ounces of gum Senegal, of ordinary quality. Stir the mixture until the latter is dissolved, then let it subside for twenty-four hours, after which, decant the ink, and preserve it in bottles of glass or stone ware for use. This recipe, it is evident from the preceding remarks, may be considerably varied without material prejudice to the quality of the article ; but it should be borne in mind that galls possess more intrinsic value (without reference to their prime cost) than their substitutes, as a given weight of them yields a greater quantity of black precipitate than any of the others; • the current price, as well as the quality of the galls, will therefore have to be duly estimated, and in apportioning the substitute a greater quantity must be used.