The Encyclopedia Americana (1920)/Blacking
BLACKING, the article employed in blacking boots and shoes, usually contains for its principal ingredients oil, vinegar, ivory, or bone black, sugar or molasses, and strong sulphuric acid, though every manufacturer has his own recipe, and endeavors to turn it to best account by concealing its composition and puffing its merits. Blacking is used either liquid or in the form of a paste, but both are obtained from the same ingredients, the only difference being that in making the paste a portion of the liquid is withheld. Blacking was introduced into England from France in the latter part of the 18th century. A celebrated old English blacking consists of 18 ounces of caoutchouc dissolved in 9 pounds of hot rape-oil, 60 pounds ivory-black, 45 pounds molasses, and 20 gallons vinegar, of strength No. 24, in which one pound finely ground gum-arabic has been dissolved. The whole mixture, after being carefully triturated in a grinding mill, receives 12 pounds sulphuric acid, in small successive quantities, stirring strongly for half an hour. The stirring is continued for half an hour daily during a fortnight, and then three pounds of gum-arabic are added, after which the stirring is resumed, and continued as before for another fortnight. This gives fine liquid blacking; the paste is obtained within a week by withholding 8 of the 20 gallons in which the gum-arabic is dissolved. Shoe blacking in liquid form may be made from powdered graphite (1 pound), lampblack (1 ounce), rosin (4 ounces) and turpentine (1 gallon). Graphite is the principal ingredient in many stove polishes. The solid cakes of stove polish are made by subjecting the powdered graphite, mixed with turpentine, to great pressure.