BLACKING. An article prepared in various ways for polishing shoes and boots. Each manufacturer has his own recipe, in which ivory black or some other black color, oil, and vinegar, with molasses, are the principal ingredients. The following is the mode of making the waterproof or India-rubber blacking : 18 ounces of caoutchoue are to be dis solved in about 9 pounds of hot rape oil. To this solution 60 pounds of fine ivory black and 45 pounds of molasses are to be added, along with 1 pound of finely ground gum arable, previously dissolved in 20 gallons of vinegar, of strength No. 21. These mixed ingredients are to he finely triturated in a paint-mill till the mixture becomes perfectly smooth. To this varnish 12 pounds of sulphuric acid are to be now added in small successive quantities, with powerful stirring for half an hour. The blacking thus compounded is allowed to stand for fourteen days, it being stirred half an hour daily ; at the end of which time, 3 pounds of finely ground gum arabic are added, after which the stirring is repeated half an hour every day for fourteen days longer, when the liquid blacking is ready for use.
In making the paste blacking, the above quantity of India-rubber, oil, ivory black, molasses, and grim arabic, may be used, the latter being dissolved in only 12 pounds of vinegar. These ingredients are to be well mixed, and then ground together in a mill till they form a perfectly smooth paste. To this paste 12pounds of sulphuric acid are to be added in small quantities at a time, with powerful stirring, which is to be continued for half an hour after the last portion of the acid has been introduced. This paste will be found fit for use in about seven days.