Cooley's Cyclopaedia of Practical Receipts Volume Ii Part 115

=Paper, Razor-strop.= 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.

=Paper, Re'sin.= _Syn._ POOR-MAN'S PLASTER; CHARTA RESINOSA, L. _Prep._ 1.

Beeswax, 1 oz.; tar and resin, of each, 3 oz.; melted together and spread on paper.

2. (Ph. Bor.) Paper thinly spread over with black pitch. Calefacient, stimulant, and counter-irritant; in rheumatism, chest affections, &c.

=Paper, Rheu'matism.= See PAPERS, GOUT, and RESIN.

=Paper, Safe'ty.= _Syn._ PAPIER DE SURETe, Fr. White paper pulp mixed with an equal quant.i.ty of pulp tinged with any stain easily affected by chlorine, acids, alkalies, &c., and made into sheets as usual.

=Paper, Test.= _Syn._ CHARTA EXPLORATORIA, L. Under this head may be conveniently included all the varieties of prepared paper employed in testing. For this purpose sheets of unsized paper or of good ordinary writing paper (preferably the first), are uniformly wetted with a solution of the salt, or with a cold infusion or decoction of the tinctorial substance in distilled water, and are then hung up to dry in a current of pure air; they are, lastly, cut into pieces of a convenient size, and preserved in closed bottles or jars. For use, a small strip of the prepared paper is either dipped into or moistened with the liquid under examination, or it is moistened with distilled water and then exposed to the fumes. A single drop, or even less, of any liquid may be thus tested.

The following are the princ.i.p.al test papers and their applications:--

PAPER, BRAZIL-WOOD. From the decoction. Alkalies turn it purple or violet; strong acids, red.

PAPER, BUCKTHORN. From the juice of the berries. Reddened by acids.

PAPER, CHERRY-JUICE. As the last.

PAPER, DAHLIA, GEORGINA P. From an infusion of the petals of the violet dahlia (_Georgina purpurea_). Alkalies turn it green; acids red; strong caustic alkalies turn it yellow. Very delicate.

PAPER, ELDERBERRY. From the juice of the berries. As the last.

PAPER, INDIGO. From a solution of indigo. Decoloured by chlorine.

PAPER, IODINE OF POTa.s.sIUM. _a._ From the solution in distilled water.

Turned blue by an acidulated solution of starch.

_b._ From a mixture of a solution of iodide of pota.s.sium and starch paste.

Turned blue by chlorine, ozone, and the mineral acids, and by air containing them.

PAPER, LEAD. From a solution of either acetate or diacetate of lead.

Sulphuretted hydrogen and hydrosulphuret of ammonia turn it black.

PAPER, LITMUS. In general, this is prepared from infusion of litmus, without any precaution, but the following plan may be adopted when a superior test paper is desired;--

_a._ (Blue.) Triturate commercial litmus, 1 oz., in a wedgwood-ware mortar, with boiling water, 3 or 4 fl. oz.; put the mixture into a flask, and add more boiling water until the liquid measures fully 1/2 pint; agitate the mixture frequently until it is cold, then filter it, and divide the filtrate into two equal portions; stir one of these with a gla.s.s rod previously dipped into very dilute sulphuric acid, and repeat the operation until the litmus infusion begins to look very slightly red, then add the other half of the filtrate, and the two being mixed together, dip strips of unsized paper into the liquid, in the usual manner, and dry them. Acids turn it red; alkalies blue. The neutral salts of most of the heavy metals also redden this, as well as the other blue test papers that are affected by acids.

_b._ (Red.) The treatment of the whole quant.i.ty of the infusion (see _above_) with the rod dipped in dilute sulphuric acid is repeated until the fluid begins to look distinctly red, when the paper is dipped into it as before. The alkalies and alkaline earths, and their sulphides, restore its blue colour; the alkaline carbonates and the soluble borates also possess the same property. Very sensitive. An extemporaneous red litmus paper may be prepared by holding a strip of the blue variety over a pot or jar into which 2 or 3 drops of hydrochloric acid have been thrown.

PAPER, MALLOW. From an infusion of the purple flowers of the common mallow. Affected like 'dahlia paper.'

PAPER, MANGANESE. From a solution of sulphate of manganese. Ozonised air blackens it.

PAPER, RHUBARB. From a strong infusion of the powdered root. Alkalies turn it brown; but boracic acid and its salts do not affect it. Very sensitive.

PAPER, ROSE. From the petals of the red rose, as the last. Alkalies turn it bright green. Dr A. S. Taylor recommends the infusion to be very slightly acidulated with an acid before dipping the paper into it. More sensitive than turmeric paper.

PAPER, STARCH. From a cold decoction of starch. Free iodine turns it blue.

PAPER, SULPHATE OF IRON. From a solution of ferrous sulphate. As a test for hydrocyanic acid and the soluble cyanides.

PAPER, TURMERIC. From decoction of turmeric (2 oz. to the pint). It is turned brown by alkalies, and by boracic acid and the soluble borates. It is not quite so susceptible as some other tests, but the change of colour is very marked and characteristic.

=Paper, Tra"cing.= _Prep._ Open a quire of smooth unsized white paper, and place it flat upon a table, then 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 quant.i.ty is finished. If not sufficiently transparent, a second coat of varnish may be applied as soon as the first has become quite dry.

2. Rub the paper with a mixture of equal parts of nut oil and oil of turpentine, and dry it immediately by rubbing it with wheaten flour; then hang it on a line for 24 hours to dry.

_Obs._ Both the above are used to copy drawings, writing, &c. If washed over with ox-gall and dried, they may be written on with ink or water colours. The first is the whitest and clearest, but the second is the toughest and most flexible. The paper prepared from the refuse of the flax-mills, and of which banknotes are made, is also called 'tracing paper,' and sometimes 'vegetable paper.' This requires no preparation; but though very flexible, it has little strength.

=Paper, Var'nished.= Before proceeding to varnish paper, card-work, pasteboard, &c., it is necessary to give it 2 or 3 coats of size, to prevent the absorption of the varnish, and any injury to the colour or design. The size may be made by dissolving a little isingla.s.s in boiling water, or by boiling some clean parchment cuttings until they form a clear solution. This, after being strained through a piece of clean muslin, or, for very nice purposes, clarified with a little white of egg, is applied by means of a small clean brush called by painters a sash tool. A light, delicate touch must be adopted, especially for the first coat, lest the ink or colours be started, or smothered. When the prepared surface is perfectly dry, it may be varnished in the usual manner. See MAPS, VARNISH, &c.

=Paper, Wa"fer.= See WAFERS.

=Paper, Waxed.= _Prep._ Place cartridge paper, or strong writing paper, on a hot iron plate, and rub it well with a lump of beeswax. Used to form extemporaneous steam or gas pipes, to cover the joints of vessels, and to tie over pots, &c.

=PAPER HANG'INGS.= The ornamental paper used to cover the walls of rooms, &c. Under the old system, the paper, after being sized and prepared with a ground colour, had the pattern produced on it by the common process of 'stencilling,' a separate plate being employed for each colour that formed the pattern. To this succeeded the use of wooden blocks, the surface of which bearing the design in relief, and being covered with colour, was applied by simple hand pressure on the paper, in a precisely similar manner to that adopted in the block-printing of calicoes. The cylinder calico-printing machine has now been successfully applied to the manufacture of paper hangings.

The colours employed for paper hangings are--

BLACKS.--Frankfort, ivory, and blue black.

BLUES. Prussian blue, verditer, and fact.i.tious ultramarine.

BROWNS. Umber (raw and burnt), and mixtures.

GRAYS. Prussian blue and blue black, with Spanish white.

GREENS. Brunswick green, Scheele's g., Schweinfurt g., and green verditer; also mixtures of blues and yellows.

REDS. Decoctions of Brazil wood (chiefly), brightened with alum or solution of tin; the red ochres; and, sometimes, red lake.

VIOLETS. Decoction of logwood and alum; also blues tempered with bright red.

YELLOWS. Chrome yellow, decoction of French berries or of weld, terra di sienna, and the ochres.

WHITES. White lead, sulphate of baryta, plaster of Paris, and whiting, and mixtures of them.

The vehicle employed to give adhesiveness and body to the colours is a solution of gelatin or glue, sufficiently strong to gelatinise on cooling.

The satiny l.u.s.tre observable in some paper hangings (SATIN PAPERS) is produced by dusting finely powdered French chalk over the surface, and rubbing it strongly with a brush or burnisher. The ground for this purpose is prepared with plaster.

FLOCK and VELVET PAPERS are produced by covering the surface of the pattern with a mordant formed with boiled oil thickened with white lead or ochre, and then sprinkling powdered woollen flocks on it. These are previously dyed, and ground to the required fineness in a mill.

=PAPIER-MaCHe.= Pulped paper moulded into forms. It possesses great strength and lightness. It may be rendered partially waterproof by the addition of sulphate of iron, quicklime, and glue or white of egg to the pulp; and incombustible by the addition of borax and phosphate of soda.

The papier-mache tea-trays, waiters, snuff-boxes, &c., are prepared by pasting or glueing sheets of paper together, and then submitting them to powerful pressure, by which the composition acquires the hardness of board when dry. Such articles are afterwards j.a.panned, and are then perfectly waterproof.