[193] By taking the ‘parts’ ordered in this and the other formulæ as so many 1⁄4 lbs., lbs., 1⁄4 cwts., or cwts., the proportions of each ingredient for any quantity of blacking, from a 1⁄4 of a lb., or a 1⁄4 pint, up to 2 tons, or nearly 450 galls., will be at once seen; and so on of even larger quantities. See Concluding Remarks (infrà).
2. Ivory-black, 16 parts; treacle, 8 parts; oil of vitriol, 4 parts; (diluted with) water, 2 parts; oil, 2 parts; gum-arabic, 1 part; soft water (for the final dilution, instead of vinegar), 64 parts; mixed, &c., as before. Excellent.
3. As the last; but taking only 6 parts of treacle, 1 part of oil, and omitting the gum-arabic. Good. A commoner article of liquid blacking does not sell.
4. (Bryant and James’s India-rubber Liquid Blacking. Patent dated 1836.) Take of india rubber (in small pieces), 18 oz.; hot
rape oil, 9 lbs. (say 1 gall.); dissolve; to the solution add of ivory-black (in very fine powder), 60 lbs.; treacle, 45 lbs.; mix thoroughly; further add of gum-arabic, 1 lb., dissolved in vinegar (No. 24), 20 galls.; reduce the whole to a perfect state of smoothness and admixture by trituration in a paint-mill; throw the compound into a wooden vessel, and add, very gradually, of sulphuric acid, 12 lbs.; continue the stirring for 1⁄2 an hour, repeating it daily for 14 days; then add of gum-arabic (in fine powder), 3 lbs.;[194] again mix well, and repeat the stirring for 1⁄2 an hour daily for 14 days longer, when the liquid blacking will be ready for use or for bottling. The quality is very excellent; but this, probably, does not depend on the presence of the india rubber, but on the general correctness of the proportions, and the care and completeness with which they are mixed.
[194] This should be gently rubbed through a sieve, held over the blacking by one person, whilst another stirs the mass assiduously with the spatula.
5. (Without Vitriol.) Take of ivory-black (in very fine powder), 2 lbs.; treacle, 11⁄2 lb.; sperm oil, 1⁄4 pint; mix, as before; then add of gum-arabic, 1 oz.; (dissolved in) strong vinegar, 1⁄2 pint; mix well; the next day further add of good vinegar, or strong sour beer, 3 to 4 pints (or q. s.); stir briskly for a 1⁄4 of an hour, and again once a day for a week. Excellent. A cheaper, but inferior article, may be made by the reductions and omissions noticed above.
6. From paste-blacking (see below), by reducing it with sufficient vinegar, sour beer, or water, to give it the liquid form.[195]
[195] It is sometimes convenient to prepare liquid blacking in this way from a stock of ‘paste-blacking’ already on hand.
II. Paste Blacking:—