To 1 ounce add twenty-four drops of boiled linseed oil: rub them thoroughly together in a mortar; then spread out the mixture, for a few days, to dry. When dry, mix with starch, dextrine solution, or gum water, and chop into3⁄8or1⁄2inch cubical blocks.
Mix together on paper, damp with lac solution, and chop into cubical blocks. The composition may also be pumped into roman candle streamer stars.
No substance combines better with salts of copper, than sugar. Sugar, put into the bowl of a tobacco pipe, and placed in the fire, burns fiercely, and is converted into caramel. This, poured on to a plate, slightly smeared with butter, to prevent its sticking, hardens on cooling; and is used for colouring brandy, vinegar, gravy, porter, coffee, &c. Stearine must be scraped very fine from a composite candle.
It is impossible to powder shellac sufficiently fine, by hand; and, twenty years ago, it could not be procured. About that time the drug-grinders, finding a demand for it, submitted it to the action of the stamping mills, (mechanical pestle and mortar), and now it can be obtained at most shops. Chertier mixed it with salt; melted the two together; powdered the mixture; and washedout the salt. Such process is needless now. It is useless, unless as fine as wheaten flour. Page, of 47, Blackfriars Road; and Chubb, of 29, Old Street, St. Lukes, London, supply it.
If powdered nitrate of barytes, and shellac crushed by being hammered in a bag, aremixed together, and melted in a pipkin, over the fire, the mixture, when cold, may be reduced to a powder in an iron mortar, with patience. Take Number 6. Weigh out 21 parts nitrate of barytes, and 2 parts of coarsely powdered lac; melt them together; when cold, powder them; and add the other substances in proper proportion. Shellac may be melted with nitrate of strontian, in the same way.