Cooley's Cyclopaedia of Practical Receipts Volume I Part 132

2. Equal weights of red lead and white lead, mixed with boiled linseed oil, to a proper consistence. Used by engineers and others to make metallic joints. A washer of hemp, yarn, or canvas, smeared with the cement, is placed in the joint, which is then "brought home," or screwed up tight. It dries as hard as stone. It also answers well for joining broken stones, however large. Cisterns built of squares stones, put together, while dry, with this cement, will never leak or come to repair.

=Cement, Extempora"neous.= 1. Sh.e.l.l-lac, melted, and run into small sticks the size of a quill. Used to join gla.s.s, earthenware, &c. The edges are heated sufficiently hot to melt the cement, which is then thinly smeared over them, and the joint made while they are still hot. This is the cement so commonly vended in the streets of London, and which used to surprise us in our boyhood days.

2. Tears of gum mastic, used in the same way. Commonly employed by jewellers and others.

_Cement, Fire'proof._ _Prep._ From fine river sand, 20 parts; litharge, 2 parts; quick-lime, 1 part; linseed oil, q. s. to form a thin paste.

Applied to walls, it soon acquires a stony hardness. It is also used to mend broken pieces of stone, stone steps, &c. See CEMENT, BEALE'S, &c.

=Cement, Flour.= _Syn._ PASTE, FLOUR PASTE. This useful and well-known article is made by mixing about a tablespoonful of wheat flour with cold water, (say) 1/2 pint, adding the latter gradually, and thoroughly stirring in each portion before pouring in more; the vessel is then placed over the fire, and the whole a.s.siduously stirred until it boils, great care being taken to prevent caking on the bottom, or burning. Some persons add about 1/3 of a teaspoonful of powdered alum to the water, which is said to strengthen the product; the shoemakers add a little quant.i.ty of powdered resin to the flour, with the same intention. The addition of a little brown sugar and a few grains of corrosive sublimate will prevent it turning mouldy, and is said to preserve it for years. When too hard or dry, it may be softened by beating it up with a little hot water.

=Cement, French.= Mucilage of gum Arabic, thickened with starch powder or farina; a little lemon-juice is sometimes added. Used by naturalists in mounting specimens; by artificial-flower makers; and by confectioners, to stick paper, wafer papers, ornaments, &c., on their fancy cakes. Plain mucilage is often used in the same way.

=Cement, Gad's.= _Syn._ GAD'S HYDRAULIC CEMENT. From clay (well dried and powdered), 3 parts; oxide of iron, 1 part; mixed together, and made into a stiff paste with boiled oil. Used for work required to harden under water.

=Cement, Gla.s.s.= _Syn._ GLa.s.s FLUX. _Prep._ Red lead, 3 parts; fine white sand, 2 parts; crystallised boracic acid, 3 parts; mixed and fused; it is levigated, and applied with thin mucilage of tragacanth. Used for mending broken china, &c. The repaired article must be gently heated, so as partially to fuse the cement.

=Cement, Gibbs'.= Mr Gibbs patented in 1850 various processes for making admirable building and architectural cements, equal in hardness and duration, and superior in colour, to the best Roman and Portland cements at present in use. His materials are obtained from "the vast beds of (natural) argillaceous marls and marly limestones, or marl stones, which contain the due admixture of lime, silica, and alumina, from which hydraulic cements and artificial stones may be manufactured." These materials he finds in "the chalk formation, the Wealden formation, the Purbeck beds, the lias formation, the mountain limestone, and the lowest strata of the coal-measures." After duly choosing his materials according to the particular object in view, he prepares them "by burning in kilns, and grinding in mills, in the way cement is now manufactured." Marls and limestones are to be "first dried in kilns or ovens, at a heat fit for baking, until all moisture be driven off, and that then the calcination be prolonged as much as possible; the heat being kept as low as is only just sufficient to effect complete calcination--this being indispensable, to avoid the commencement of vitrification, which would destroy the adhesive properties of the cement."

=Cement, Glue.= _Prep._ 1. From glue, 1 lb. melted with the least possible quant.i.ty of water, and then mixed with black resin, 1 lb., and red ochre, 4 oz.

2. Glue, melted as above, and mixed with about 1/4th of its weight each of boiled oil and red ochre.

3. (Ure.) Melted glue (of the consistence used by carpenters), 8 parts; linseed oil, boiled to varnish with litharge, 4 parts; incorporate thoroughly together.

4. Glue (melted as last), 4 parts; Venice turpentine, 1 part.

_Obs._ The first three dry in about 48 hours, and are very useful to render the joints of wooden casks, cisterns, &c., watertight; also to fix stones in frames. The last serves to cement gla.s.s, wood, and even metal to each other. A good cement for fixing wood to gla.s.s may be made by dissolving isingla.s.s in acetic acid, in such quant.i.ties that it becomes solid when cold. When applied let it be heated. They all resist moisture well.

=Cement, Grind'ers'.= _Prep._ 1. From pitch, 5 parts; wood ashes and hard tallow, of each 1 part; melted together.

2. Black resin, 4 lbs.; beeswax, 1 lb. melt, and add of whiting (previously heated red hot, and still warm), 1 lb.

3. Sh.e.l.l-lac, melted and applied to the pieces slightly heated. Used to fix pieces of gla.s.s, &c., whilst grinding. The last is used for lenses and fine work.

=Cement, Hamelin's.= _Syn._ HAMELIN'S MASTIC. From siliceous sand, 60 parts; Bath or Portland stone (in fine powder), 40 parts; lime-marl, 20 parts; litharge, 8 parts; ground together. For use it is mixed up with linseed oil and used like mortar. When this cement is applied to the purpose of covering buildings intended to resemble stone, the surface of the building is first washed with linseed oil.

=Cement, Hensler's.= Litharge, 3 parts; quick-lime, 2 parts; white bole, 1 part (all in fine powder); linseed-oil varnish, q. s. to make a paste.

Used for china, gla.s.s, &c. It is very tenacious, but long in drying.

=Cement, Hnle's.= Sh.e.l.l-lac, 2 parts; Venice turpentine, 1 part; fused together, and formed into sticks. It is used like extemporaneous cement for gla.s.s and earthenware.

=Cement, Hydraulic.= Hydraulic mortars or cements are those which set or become hard under water. Common lime does not possess this property; but limestone containing from 8% to 25% of alumina, magnesia, and silica, yield a lime on burning, which does not slake when moistened with water, but forms a mortar with it, which hardens in a few days when covered with water, although it does not acquire much solidity in the air. Puzzolana, septaria, and argillaceous or siliceous earths, burnt, either with or without the addition of common limestone, and then ground to powder, form excellent hydraulic cements. The reniform limestone, commonly called "cement stone," which is found distributed in single nodules or lenticular cakes, in beds of clay, is the substance most commonly used in this country for the manufacture of the cements in question.

"A very good hydraulic mortar is made by slaking lime with water containing about 2 per cent. of gypsum, and adding a little sand to the product. The presence of the gypsum tends to delay the slaking of the lime, and also to harden the substance formed after the slaking.

"If water containing a little lime in solution be added to burnt gypsum, a very hard compact ma.s.s is obtained. This substance is much used as an imitation marble, as by polis.h.i.+ng it with pumice stone, colouring it, and again polis.h.i.+ng with oil, it may be made to resemble natural marble very closely. Hardened gypsum treated with stearic acid, or paraffin, and polished, is used as a subst.i.tute for meerschaum, which it much resembles."[238] See GAD'S, HAMELIN'S, and PARKER'S CEMENTS, &c.

[Footnote 238: 'Chemistry, Theoretical, Practical, and a.n.a.lytical.']

=Cement, Iron.= This cement, which is much used for closing the joints of iron pipes and similar purposes, is formed of the borings or turnings of cast iron, which should be clean and free from rust, mixed with a small quant.i.ty of sal-ammoniac and flowers of sulphur. For use, it is stirred up with just enough water to thoroughly moisten it, and it is rammed or caulked into the joints with a blunt caulking chisel and hammer, after which the joint is screwed up by its bolts as tightly as possible. If the turnings and borings are very coa.r.s.e they are broken by pounding in an iron mortar, and the dust sifted off before use. The following are good proportions:

1. Sal-ammoniac (in powder), 2 oz.; flowers of sulphur, 1 oz.; iron borings, 5 lbs.; water, q. s. to mix.

2. Sal-ammoniac, 2 oz.; sulphur, 1 oz.; iron borings, 12 lbs.; water, q.

s. to mix.

3. Sal-ammoniac, 2 oz.; iron borings, 7 or 8 lbs.; water, q. s. to mix.

4. Iron borings, 4 lbs.; good pipeclay, 2 lbs.; powdered potsherds, 1 lb.; make them into a paste with salt and water.

_Remarks._ The first of these forms is that generally employed for common purposes, but formerly much more sulphur and sal-ammoniac were used. We are told by one of the leading engineers in London that the strongest cement is made without sulphur and with only 1 or 2 parts of sal-ammoniac to 100 of iron borings (see the third form); but that when the work is required to dry rapidly, as for the steam joints of machinery wanted in haste, the quant.i.ty of sal-ammoniac is increased a little, and a very small quant.i.ty of sulphur is added. This addition makes it set quicker, but reduces its strength. As the power of the cement depends on the oxidation and consequent expansion of the ma.s.s, it is evident that the less foreign matter introduced the better. No more of this cement should be made at a time than can be used at once, because it soon spoils. I have seen it become quite hot by standing even a few hours, when it contained sulphur; and I have been informed by workmen that when much sulphur is used, and it has been left together in quant.i.ty all night, combustion has taken place. The last form produces a cement that gets very hard when allowed to dry slowly, and is excellent for mending cracks in iron boilers, tanks, &c.

CEMENT, j.a.pANESE. _Syn._ RICE GLUE. From rice flour, mixed with a little cold water, and boiling water gradually poured in until it acquires a proper consistence; when it is boiled for 1 or 2 minutes in a clean saucepan or earthen pipkin. It is beautifully white, and almost transparent, for which reason it is well adapted for fancy paper work, which requires a strong and colourless cement. It is superior to French cement. (See _ante_.)

=Cement, Keene's Marble.= Baked gypsum or plaster of Paris, steeped in a saturated solution of alum, and then recalcined, and reduced to powder.

For use it is mixed up with water, as ordinary plaster of Paris.

_Obs._ This cement has been most extensively applied as a stucco. It is susceptible of a high polish, and when coloured produces beautiful imitations of mosaic and other inlaid marbles, scagliola, &c. It is not adapted to hydraulic purposes, or for exposure to the weather, but it is admirable for internal decorations, and from its extreme hardness is very durable. It may be coloured or tinted of any shade, by diffusing mineral colours (levigated, if in powder) through the water used to mix up the cement with. A pleasing tint is given to this cement by adding a little solution of green copperas to the alum liquor.

=Cement, Laboratory.= _Syn._ CHEMICAL MASTIC. From equal parts of pitch, resin, and plaster of Paris (thoroughly dried), mixed together. Used for the masonry of chlorine chambers, vitriol works, &c.; and as a lining for casks intended to hold chloride of lime.

=Cement, Letter-fixing.= _Prep._ Copal varnish, 15 parts; drying oil, 5 parts; turpentine, 3 parts; oil of turpentine, 2 parts; liquefied glue (made with the least possible quant.i.ty of water), 5 parts; melt together in a water bath, and add fresh slaked lime (perfectly dry, and in very fine powder), 10 parts. Used to attach metal letters to plate gla.s.s in shop windows, &c.

=Cement, Mahogany.= _Prep._ 1. Melt beeswax, 4 oz.; then add Indian red, 1 oz., and enough yellow ochre to produce the required tint.

2. Sh.e.l.l-lac, melted and coloured as above. Very hard. Both are used to fill up holes and cracks in mahogany furniture by the cabinet makers. Red putty is also used for the same purpose.

=Cement, Maissiat's.= India rubber is melted either with or without about 15% of either beeswax or tallow; quick-lime (in fine powder) is gradually added; and the heat continued until change of odour shows that combination has taken place, and until a proper consistence is obtained. Used as a waterproof and air-tight covering for corks, bungs, &c.

=Cement, Marine.= See GLUE, MARINE, and CEMENT, ELASTIC.

=Cement, Martin's.= This is manufactured in the same way as Keene's, only carbonate of soda or carbonate of potash is used as well as alum, and the burning is carried on at a higher temperature.

=Cement, Opticians'.= _Prep._ 1. Sh.e.l.l-lac softened with rectified spirit or wood naphtha. For fine work.

2. Beeswax, 1 oz.; resin, 15 oz.; melt and add whiting (previously made red hot, and still warm), 4 oz.

3. Resin, 1 lb.; melt and add plaster of Paris (dry), 4 oz. The above are used to fix gla.s.ses, stones, &c., while polis.h.i.+ng and cutting them. The last is a very strong cement for rough purposes.

=Cement, Oxychlo"ride of Zinc.= (Sorel.) _Prep._ In solution of chloride of zinc, marking from 50 to 60 of Baume's hydrometer (_i.e._ sp. gr.

1490 to 1652), dissolve 3% of borax or sal-ammoniac; then add oxide of zinc which has been heated to redness, until the ma.s.s is of a proper consistence.

_Obs._ This cement becomes as hard as marble. It may be cast in moulds like plaster of Paris, or used in mosaic work, &c.

=Cement, Parabol'ic.= _Syn._ UNIVERSAL CEMENT. _Prep._ Curdle skim milk with rennet or vinegar, press out the whey, and dry the curd by a very gentle heat, but as quickly as possible. When it has become quite dry grind it in a coffee or pepper mill, and next triturate it in a mortar until reduced to a very fine powder. Mix this powder with 1/10th of its weight of new dry quick-lime, also in very fine powder, and to every ounce of the mixture add 5 or 6 gr. of powdered camphor; triturate the whole well together, and keep it in wide-mouth 1-oz. phials, well corked. Used to join gla.s.s, earthenware, &c. It is made into a paste with a little water, as wanted, and applied immediately.

=Cement, Parian.= Is prepared as Keene's, subst.i.tuting a solution of borax (1 part of borax to 9 of water) for a solution of alum.