1943. To Make Fireproof Paper

1943.      To Make Fireproof Paper. Newspapers may be rendered fireproof by dipping into a solution of soluble glass of 25° Baum'e; next neutralizing the alkali by diluted muriatic acid of 10° Baum'e while hot, and drying by the atmosphere. Fire cannot then destroy the texture of the paper.

1944. To Make Paper Waterproof

1944.    To Make Paper Waterproof. Melt in 10 pints hot water, 30 ounces glue, gelatine or size, and 3 ounces gum-arabic. In another 30 pints hot water, melt 20 ounces soap and 4 pounds alum; mix both liquids together in one pot. This constitutes composition No. 1. In another pot heat 1/2 gallon benzole and 1 gallon paraffine, and melt in it 24 ounces resin; let it boil until it attains a moderate degree of consistency. To these materials, resin, oil, and copal or mastic varnish may, in some cases, be added. This is composition No. 2. First dip the article to be waterproof into the composition No. 1 in a heated state, and then dry it. Next apply composition No. 2, in a cooled state, with a brush, or in any other convenient manner.

1945. Papier-Mache

1945.    Papier-Mache. A plastic material, formed of cuttings of white or brown paper, boiled in water, beaten to a paste in a mortar, and then mixed with a solution of gum-arabic in size, to give tenacity. It is variously manufactured by being pressed into oiled moulds, afterwards dried, covered with a mixture of size and lamp-black, or otherwise ornamented, and varnished.

1946. To Detect the Presence of Plaster in Paper

1946.      To Detect the Presence of Plaster in Paper. Calcine the paper in a close vessel, and dilute the residue with vinegar, in a silver spoon; if sulphuretted hydrogen is disengaged, which blackens the spoon, the presence of a sulphate (plaster) will be shown. This adulteration has lately become very common among the paper-makers, with the view of increasing the weight.

1947. To Detect Woody; Fibre in

1947.     To Detect Woody; Fibre in. Paper. The paper is touched with ordinary strong nitric acid. If wood fibre is present the paper will bo colored brown, especially on warming.

1948. Magic Copying Paper

1948.     Magic Copying Paper. To make black paper, take lamp-black mixed with cold lard. Bed paper — Venetian red mixed with lard. Blue paper - Prussian blue mixed with lard. Green paper - chrome green mixed with lard. The above ingredients to be mixed to the consistency of thick paste, and applied to the paper with a rag. Then take a flannel rag, and rub until all the color ceases coming off. These sheets, alternated with writing paper and written on with a solid pen, produce 2 or 3 copies of a letter at once.

1949. Manifold Copying Process

1949.      Manifold Copying Process. This is a method patented by Mr. Underwood, of London, for taking copies of writing by pressure;. by this means as many as twenty copies or more of a letter or other writing can be obtained.

The copying paper is prepared by being wetted with a solution of 200 grains of the yellow or neutral chromate of potash in 1 gallon of distilled water. This paper can be used immediately, or may be dried, and damped with water when required for use. The copying ink to be used for the original writing must be made by dissolving (in a water-bath) about 6 pounds pure extract of logwood in 1 gallon distilled water.

Damp 6 sheets of the prepared paper, and remove all superfluous moisture with good blotting paper, place the original writing on the upper sheet, and put in the copying-press for about half a minute; then remove the original and substitute in its place 6 more damp sheets of the paper, and press for a quarter of an hour. Then take the original again and lay it on the top of 5 more damped sheets of the paper, and press for about two minutes; finally remove the original, and in its place put 3 more sheets of the paper, then press for a quarter of an hour. This process will give twenty copies. If more than twenty copies are to be made, the writing of the original should, before the ink is quite dry, be dusted over with a powder composed of 5 parts extract of logwood, 1 part powdered gum-arabic, and 1 part powdered gum-traga-canth.