To Make Incombustible Writing and Printing Paper.
To make incombustible writing and printing paper, asbestos of the best quality is treated with potassium permanganate and then with sulphuric acid. About ninety-five per cent of such asbestos is mixed with five per cent of wood pulp in water containing borax and glue. A fire proof ink is made of platinous chloride and oil of lavender, mixed for writing with India ink and gum, and for printing with lampblack and varnish.