I

Dip white unsized paper for half a minute in strong sulphuric acid, specific gravity, 1.842, and afterwards in water containing a little ammonia.

II

Plunge unsized paper for a few seconds into sulphuric acid diluted with half to a quarter its bulk of water (this . solution being of the same temperature as the air), and afterwards wash with weak ammonia.

Razor Paper

I

Smooth unsized paper, one of the surfaces of which, while in a slightly damp state, has been rubbed over with a mixture of calcined peroxide of iron and emery, both in impalpable powder. It is cut up into pieces (about 5x3 inches), and sold in packets. Used to wipe the razor on, which thus does not require stropping.

II

From emery and quartz (both in impalpable powder), and paper pulp (estimated in the dry state), equal parts, made into sheets of the thickness of drawing paper, by the ordinary process. For use, a piece is pasted on the strop and moistened with a little oil.

Safety Paper

White paper pulp mixed with an equal quantity of pulp tinged with any stain easily affected by chlorine, acids, alkalies, etc., and made into sheets as usual, serves as a safety paper on which to write checks or the like. Any attempt to wash out the writing affects the whole surface, showing plainly that it has been tampered with.

Tracing Paper

Open a quire of smooth, unsized white paper, and place it flat upon a table. Apply, with a clean sash tool to the upper surface of the first sheet, a coat of varnish made of equal parts of Canada balsam and oil of turpentine, and hang the prepared sheet across the line to dry; repeat the operation on fresh sheets until the proper quantity is finished. If not sufficiently transparent, a second coat of varnish may be applied as soon as the first has become quite dry.