Chapter II: BLEACHING of =Linen=:--Linen may be bleached in a similar way to (11)

=CAS'TOR.= _Syn._ CASTO''REUM, L. (B. P.) "The follicles of the prepuce of the _Castor fiber_ or _beaver_, filled with a peculiar secretion." (Ph. L.) "A peculiar secretion from the præputial follicles." (Ph. E. and D.) It is often sophisticated; a fraud readily detected by the "absence of the membranous partition in the interior of the bags, as well as by the altered smell and taste." (Ure.) Russian castor, which is very rare, may be distinguished by a tincture of 1-16th part in alcohol, being of the colour of deep sherry, while that with American castor is of the colour of London porter. (Pereira.)--_Dose_, 1 to 2 dr. or more, in powder or made into pills; in nervous and spasmodic affections, especially in hysteria, epilepsy, and other like diseases of females.

=CASTOR CAKE.= The crushed and closely-pressed seeds of the _Ricinus communis_, after the expression of the oil, are said to be sometimes employed as a cattle food, and have the following composition:--

Moisture 9·95
Organic matter 81·07
Phosphate of lime and magnesia 4·49
Alkaline salts 1·80
Sand 2·69
------
100·00

This cake, even when mixed with large quantities of linseed cake, &c., is intensely poisonous. A pupil of the Editor states, however, that in India castor cake, after exposure to the sun, is commonly and safely used as a food for cattle.

=CAS'TOR OIL.= See OILS.

=CAS'TORIN.= _Syn._ CASTORIN'A, CASTOREUM CAMPHOR. When castor is cut into small pieces and boiled in about 6 times its weight of alcohol, crystalline substance (_castorin_) is deposited by the filtered tincture in cooling. By re-solution in alcohol it may be obtained under the form of colourless, prismatic, acicular crystals.

_Obs._ Genuine Russian castor, although the most expensive, must be employed in the above process, as scarcely any castorin can be obtained from the American variety.

_Prop., &c._ Castorin has the odour of castor, and a coppery taste; it is inflammable, and is soluble both in ether and hot alcohol.

=CASTS.= In preparing casts and moulds with gelatin, wax, fusible metal, and similar substances, it is important to use them at the lowest temperature compatible with fluidity; as when only a few degrees hotter the water which adheres to the things from which the casts are taken is converted into vapour, and produces bubbles. Fusible metal may be allowed to cool in a teacup until just ready to set at the edges, and then poured into the moulds. In this way beautiful casts from moulds of wood, or of other similar substances, may be procured. When taking impressions from gems, seals, &c., the fused alloy should be placed on paper or pasteboard, and stirred about till it becomes pasty, from incipient cooling, at which moment the gem, die, or seal should be suddenly stamped on it, and a very sharp impression will then be obtained.

=CATALEP'SY.= _Syn._ TRANCE; CATALEP'SIS, CATALEP'SIA, L. A disease in which the organs of sense and motion cease to exercise their functions, and the heart and lungs feebly perform their offices, and in a scarcely perceptible manner. The paroxysm generally comes on without previous warning, and its duration varies from a few minutes to several days, and if medical reports are to be credited, sometimes for a much longer period. Dr Cullen seriously affirms that this disease is always counterfeited.

_Treat._ Ammoniacal stimulants applied to the nostrils, and spirituous liquors injected into the stomach, with general friction of the body, and free access to pure air are the best remedies. Electricity and galvanism should also be had recourse to when the necessary apparatus is at hand.

=CAT'APLASMS.= See POULTICES.

=CAT'ARACT.= An opaque condition of the lens of the eye. It is a common cause of blindness. It can only be cured by a surgical operation.

=CATARRH'.= _Syn._ CATARRH'US, L. The "cold in the head," or "cold on the chest," of domestic medicine. Influenza is a severer form of this complaint, and has been called epidemic catarrh.

The common symptoms of catarrh are a copious discharge from the eyes and nose, a hoarseness, and generally a cough, more or less severe. The exciting causes are sudden changes of temperature and exposure to currents of cold air while the body is heated; hence the frequency of colds in hot and changeable weather.

_Treat._ A light diet should be adopted, and animal food and fermented and spirituous liquors should be particularly avoided. Some mild aperient should be administered; and when the symptoms are severe, or fever or headache is present, small diaphoretic doses of antimonials, accompanied by copious draughts of diluents, as barley water, weak tea, or gruel should be taken. This treatment, except in very bad cases, will generally effect a cure.

In HORSES catarrh is caused by sudden changes of temperature, draughts, and faulty ventilation. Let the animal have plenty of cool fresh air, the body being kept warm by means of horse-cloths and bandages. If necessary, give a mild physic-ball, or a clyster; keep it on a soft, laxative diet, and give it an ounce of nitre daily. Should there be sore throat or troublesome cough apply a mild blister of cantharides or mustard.

The following will be found a serviceable mixture:--Mendererus spirit, 1-1/2 oz.; sweet spirit of nitre, 2 drachms; syrup of sugar, 1/2 oz.; camphor mixture, enough to make a 6-oz. mixture. An adult may take two table-spoonfuls of this mixture every 3 or 4 hours. Should the cold in the head be severe and accompanied with cough, it has been recommended to inhale the vapour of pure washed ether by drawing it alternately into the nostrils from a wide-mouthed bottle holding about an ounce, and clutching it in the warm hand until about a fourth of the ounce has been volatilised. This repeated two, three, or four times in 48 hours is said to effect a cure within that time. Persons liable to colds are advised to use the cold bath.

_Dr Ferrier's Remedy for a Cold in the Head._--Hydrochlorate of morphia, 2 gr.; powdered gum Arabic, 2 drachms; subnitrate of bismuth, 6 drachms. Mix. Let a very small quantity be sniffed up the nose every five minutes for 20 or 30 minutes.

Another remedy: Carbolic acid, 10 drops; tincture iodine; chloroform, of each 7-1/2 grams. Place a few drops in a test-tube, and heat cautiously over a spirit-lamp, and when it boils remove, and inhale by the nose. Repeat after a few minutes. Two inhalations are said to be sufficient to cure a cold in the head. ('Year-book of Pharmacy.')

=CAT'ECHIN.= _Syn._ CATECHU'IC ACID, RESINOUS TAN'NIN. When cubical gambir or catechu, in powder, is treated with cold water, a portion remains undissolved. This is catechin. By repeated solutions in alcohol it may be obtained under the form of white, silky, acicular crystals.

_Prop., &c._ Catechin strikes a green colour with the salts of iron, but does not precipitate gelatin. When dissolved in caustic potassa, and the solution exposed to the air, it absorbs oxygen, and japonic acid is formed. If, instead of caustic potassa, carbonate of potassa is employed, it is converted into rutic acid.

=CAT'ECHU.= _Syn._ CAS''HEW, CUTCH, GAM'BIR; CAT'ECHU (Ph. L. E. & D.), TER'RA JAPON'ICA, L.; CACHOU, Fr. "The extract from the wood of _Acacia Catechu_, or from the leaf of _Uncaria Gambir_." (PALE CATECHU, Catechu Pallidum, B. P.) Also of the "kernels of _areca catechu_; probably, too, from other plants." (Ph. E.) The term is now applied to several extracts similar in appearance and properties to that of _Acacia Catechu_.

There are several varieties of catechu known in commerce, of which the principal are--

CATECHU, BOMBAY. Firm, brittle, dark brown, of a uniform texture, and a glossy, semi-resinous, and uneven fracture, Sp. gr. 1·39. Richness in tannin, 52%.

CATECHU, BENGAL. Rusty brown colour externally; porous, and more friable than the preceding. Sp. gr. 1·28. Richness in tannin, 49·5%.

CATECHU, MALABAR. Resembles the last in appearance, but is more brittle and gritty. Sp. gr. 1·40. Richness in tannin, 45·5%.

Of the above varieties the first is the one generally employed in medicine, and which commonly passes by the name of catechu. The second popularly passes under the name of _terra Japonica_ (Japan earth), from the old belief that it was of mineral origin.

CATECHU, PALE, is prepared at Singapore and in the Eastern Archipelago. It generally occurs in cubical reddish-brown pieces, porous, bitter, and astringent in taste. Entirely soluble in boiling water; the solution, when cold, is not rendered blue by iodine. Of 100 parts, only 60 are dissolved by cold water, and the solution is bright. Thirty parts of isinglass precipitate the whole of the astringent matter.--_Test._ Sp. gr. 1·39. "The pale catechu being already in the Edin., the B. P. 1864 retained it with the black; but the black is the one adopted by all other pharmacop[oe]ias, and is preferred in the arts and manufactures; it is well known to be far superior to the pale in astringency, and is always to be had of good quality; it is therefore a matter of surprise and regret that it has been rejected from the 'British Pharmacop[oe]ia.'" (Squire.)

_Estim._ It is often of importance to the tanner and dyer to determine the richness of this article in tannic acid or tannin. The following are two simple methods:--

1. Exhaust a weighed sample (in powder) with ether, and evaporate by the heat of a hot-water bath. The product, which is the tannin, must then be accurately weighed.

2. Dissolve the sample (in powder) in hot water, let it cool out of contact with the air, filter, and add a solution of gelatin as long as a precipitate falls. The precipitate, after being washed and dried at a steam heat, contains 40% of tannin.

_Uses, &c._ Catechu is extensively employed in medicine, both internally and externally, as an astringent. It is used to flavour British brandy, and by the tanners as a substitute for oak bark. With it the dyer produces, inexpensively, many of his most pleasing browns. Alum mordants are mostly employed in dyeing with catechu. "The salts of copper with sal-ammoniac cause it to give a BRONZE COLOUR, which is very fast; the protochloride of tin, a BROWNISH YELLOW; the perchloride of tin, with the addition of nitrate of copper, a DEEP-BRONZE HUE; acetate of alumina, alone, a REDDISH BROWN, and with nitrate of copper, a REDDISH-OLIVE GREY; nitrate of iron, a DARK-BROWN GREY. For dyeing a GOLDEN COFFEE-BROWN, it has entirely superseded madder; 1 lb. of it being equivalent to 6 lbs. of this root." (Ure.)--_Dose_, 10 gr. to 30 gr. in solution, in water, or made into a bolus, or sucked as a lozenge.

=CAT'GUT.= The prepared and twisted intestines of animals. _Prep._ The guts, taken whilst warm from the animal, are thoroughly cleaned, freed from adherent fat, and well rinsed in pure water. They are next soaked for about 2 days in water, after which they are laid on a table and scraped with a copper plate, having a semicircular notch, beginning the operation at the smaller end. In this way the mucous and peritoneal membranes are removed. The guts are then put into fresh water, and soaked until the next day, when they are again scraped, the larger ends cut off, and after well washing, again steeped for a night in fresh water, and then for 2 or 3 hours in a weak lye of pearlash or potash (2 oz. to the gall.) They are lastly washed in clean water, and passed through a polished hole in a piece of brass to smooth and equalise their surface; after which they are twisted, and sorted, according to the purposes for which they are intended. For many purposes the prepared gut is dyed or sulphured, and rubbed with olive oil. It improves by age. Red or black ink, or any of the simple dyes or stains, are used to colour it.

_Uses, &c._ Catgut is employed in several of the arts. The strings of harps, violins, &c., are formed of this material. Whipcord is made from catgut, which is sewed together while soft with the filandre or scrapings, after which it is put into a frame and twisted. Bowstrings for hatmakers are made out of the largest intestines, 4 to 12 of which are twisted together, until the cord is extended to 15 to 25 feet in length. It is then rubbed perfectly smooth and free from knots, half dried, sulphured twice, again stretched and sulphured, and lastly dried in a state of tension. Clock-makers' cords are made of the smallest intestines in a similar manner.

The best fine catgut is made at Venice or Rome, from the intestines of thin, sinewy sheep. That made in England is formed from the fat sheep killed for the shamble, and is, hence, inferior. Coarse catgut, for turning lathes, &c., is made from the intestines of horses, cut into 4 or 5 strips, by forcing a ball furnished with projecting knives placed cross-wise along them. These strips are next twisted, dried, and rubbed smooth with fish skin. Gutta percha and vulcanised india rubber are now applied to many of the purposes formerly exclusively occupied by catgut.

=CATHAR'TICS.= See PURGATIVES.

=CATHAR'TIN.= The purgative principle of senna, first noticed by Lassaigne and Fenuelle. A strong aqueous infusion of senna leaves is evaporated to the consistence of a syrup, out of contact with the air; this fluid extract is then digested in alcohol or rectified spirit, and the tincture, after filtration, is evaporated to dryness by a gentle heat.

_Prop., &c._ A reddish-coloured, uncrystallisable mass; having a peculiar odour and a bitter, nauseous taste; freely soluble in both water and alcohol, and strongly cathartic. Two or three grs. cause nausea, griping, and purging. It has been proposed to employ it, combined with aromatics, as a cathartic.

=CATH'ETERS.= Small tubes introduced into the bladder for the purpose of drawing off its contents. They may be regarded as hollow bougies.

_Prep._ 1. A piece of smooth catgut, or steel wire, bent to the proper shape, is coated with melted wax. When cold it is dipped repeatedly into an ethereal solution of india rubber, until a sufficient thickness is obtained, after which it is dried by a gentle heat, and then boiled in water to melt out the wax, and to allow the catgut to be withdrawn. A solution of india rubber in bisulphide of carbon is now generally employed instead of an ethereal solution.

2. From slips of india rubber, as directed under BOUGIES.

3. A smooth tissue of silk is woven over a bent wire, and then coated with a surface of india rubber, or elastic varnish, and finished off as before. See BOUGIES.

=CAUDLE.= Gruel enriched by various additions.

_Prep._ 1. Thick oatmeal gruel mixed with about one half its weight of good mild ale (made hot), and as much sugar, and mace, nutmeg, or ginger, as will make it agreeable.

2. To the last add an egg, well beaten.

3. Sugar, 3 or 4 lumps; hot water, a table-spoonful; dissolve; add 1 egg; beat well together; further add a glass of wine and a little nutmeg or ginger; mix well, and stir the mixture into good gruel (hot), 3/4 pint.

_Uses, &c._ A nourishing and restorative mixture during convalescence, much used among certain classes after accouchement. It is an excellent domestic remedy for colds, &c., unaccompanied with fever; for which purpose it should be taken on retiring to rest at night, preceded by a dose of castor oil during the day.

=CAULIFLOWER.= Like the cabbage, the cauliflower forms a very nutritious article of diet; rich in albumenoids and phosphates. The ash, as will be seen from the subjoined analysis, contains a large amount of mineral matter:--

_Ash of Cauliflower._

Potash 34·39
Soda 14·79
Magnesia 2·38
Lime 2·96
Phosphoric acid 25·84
Sulphuric acid 11·16
Silica 1·92
Phosphate of iron 3·67
Chloride of sodium 2·78

=CAUS'TIC.= _Syn._ CAUS'TICUM, ESCHAROT'I-CUM, L. A substance that corrodes or destroys the texture of organised bodies. This action is popularly termed "burning."

The principal caustics are nitrate of silver, caustic potassa, a mixture of caustic potassa and quick-lime, sulphate of copper, red oxide of mercury, verdigris, tincture of sesquichloride of iron, chloride of zinc, chloride of antimony, nitric acid, acetic acid, and carbolic acid.

_Use._ Caustics are employed to remove excrescences, morbid growths, granulations, &c., as corns, warts, and proud flesh; and to open issues, abscesses, &c. The first, second, and fourth are applied by gently rubbing them on the part previously moistened with water; the third is commonly made into a paste, with rectified spirit or glycerin, before application; red oxide of mercury and verdigris (in the form of powder) are often sprinkled over foul and indolent ulcers; whilst the acids and other liquid caustics are applied with a feather, camel-hair pencil, or glass rod. The same applies to the liquid preparations below. In all cases care should be taken to confine the application to the affected part.

=Caustic, Ammoni'acal.= See OINTMENTS, and CAUSTIC, GONDRET'S.

=Caustic, Antimo''nial.= _Syn._ CAUSTICUM ANTIMONIA'LE, L. Chloride of antimony.

=Caustic, Arsen'ical.= _Syn._ CAUSTICUM ARSENICA'LE, C. ARSENIO'SUM, C. A. COMPOS'ITUM, L. _Prep._ 1. See CAUSTIC, PLUNKET'S.

2. (Cutan. Hosp.) Calomel, 2-1/2 oz.; red sulphide of mercury, 1 dr.; arsenious acid, 1 dr. to 2 dr.

3. (Van Mons.) Arsenious acid, 6 dr.; dragon's blood, 2 dr.; animal charcoal, 1-1/2 dr.; cinnabar, 3 oz.

4. (Ratier.) Arsenious acid, 1 part; kino, 8 parts; cinnabar, 16 parts. The ingredients of the last three must be separately reduced to fine powder, and then carefully mixed. They are favourite applications on the Continent, in cases of cancer, cancerous sores, obstinate lepra, &c. They are either dusted over the part, or are made into a paste with mucilage or the saliva, and applied like an ointment on a piece of rag or lint; due caution being observed, and the effects watched. The last is much used in the French hospitals.

=Caustic, Canquoin's.= See ZINC CAUSTIC.

=Caustic, Canthar'ides.= _Syn._ CAUSTICUM CANTHAR'IDIS, L. _Prep._ 1. Powdered cantharides made into a paste with concentrated acetic acid.

2. (Cutan. Hosp.) Tannin, 1 oz.; cantharides (powdered), 2 oz.; strong acetic acid, 8 oz.; digest a week, and strain. Blisters.

=Caustic, Common.= See POTASSA (HYDRATE OF), and CAUSTIC OF POTASSA WITH LIME.

CAUSTIC, DUVILLE'S. _Prep._ 1. Aloes, 5 oz.; proof spirit, 10 oz.; oil of vitriol, 6 oz.; mix.

2. Aloes (in powder), 2-1/2 oz.; rum, 1/4 pint; mix, and the next day add, oil of vitriol, 1 oz. A favourite caustic in veterinary practice; especially in foot-rot.

=Caustic, Filho's.= _Prep._ From caustic potassa, 2 parts; quick-lime (in powder), 1 part; melt together in a ladle, mix well, and pour it into small leaden tubes, the size of a large swan-quill. When cold, coat each piece with melted beeswax, to exclude the air. Used as a strong caustic in veterinary practice. It is applied like nitrate of silver.

=Caustic, Golden.= _Syn._ CAUSTIC OF CHLORIDE OF GOLD; CAUSTICUM AUR'EUM, C. AUR''II CHLOR'IDI, L. _Prep._ 1. (Recamier.) Terchloride of gold, 6 gr.; nitro-hydrochloric acid, 1 oz.; dissolve.

2. (Legrand.) As the last, but using nitric acid. Both are recommended as caustics in syphilitic, scrofulous, and scorbutic ulcers, cancerous growths, &c.; applied by means of a dossil of lint.

=Caustic, Gondret's.= _Syn._ GONDRET'S AMMONI'ACAL CAUSTIC; POMMADE DE GONDRET, Fr.; CAUSTICUM AMMONIACA'LE, L. _Prep._ 1. See OINTMENT, AMMONIACAL.

2. (Original formula.) Almond oil, 2 dr.; suet, 4 dr.; lard, 6 dr.; melt together in a wide-mouthed bottle, cool a little, add solution of ammonia, 12 dr.; and agitate until cold. A powerful rubefacient and counter-irritant; used to produce an immediate revulsion. If covered with a compress, it raises a blister in 4 or 5 minutes.

=Caustic, I'odine.= _Syn._ CAUSTICUM IODIN'II, L. _Prep._ (Lugol.) Iodine and iodide of potassium, of each 1 part; water 2 parts; dissolve. Used in similar cases to iodine paint, and to scrofulous growths and ulcers.

=Caustic, Lu''nar.= _Syn._ LA'PIS INFERNA'LIS, L. _Prep._ 1. Nitrate of silver fused and formed into sticks by pouring it into moulds.

2. (E. R. Squibb.) Nitrate of silver fused with a small quantity of chloride of iron, and formed into sticks or points. The chloride of iron gives toughness to the caustic.

=Caustic, Mercu''rial.= _Syn._ CAUSTIC OF NITRATE OF MERCURY; CAUSTICUM AC'IDI HYDRAR''GYRI NITRA'TIS, C. H. DEUTRONITRATIS, L. From mercury, 1 part; commercial nitric acid, 2 parts; dissolve.

2. (Cutan. Hosp.) Mercury, 1 part; nitric acid (sp. gr. 1·5), 2 parts.

3. (P. C.) As No. 1, but evaporating the solution to 3/4ths its weight. These liquids are applied with a pencil or lint, in scrofulous and syphilitic ulcers and eruptions, and in lupus, psoriasis, lepra, and other obstinate skin diseases; but their use requires great care.

4. (With arsenic.--Cutan. Hosp.) Mercury, 1/2 oz.; nitric acid, 1/2 oz.; arsenious acid, 1/2 dr.; as before.

=Caustic, Ni'tric.= _Syn._ SOLID'IFIED NITRIC ACID; CAUSTICUM NI'TRICUM, L. _Prep._ (Dr Rivallie.) Concentrated nitric acid is gradually dropped on a piece of lint, placed in a saucer or glass; as soon as the lint is gelatinised, it is pressed into a suitable shape with a glass rod, and applied to the part; it must be removed in 15 minutes. In cancerous tumours, fungoid growths, &c.

=Caustic, O''piated.= _Syn._ CAUSTICUM OPIA'TUM, L. _Prep._ 1. Common caustic (potassa with lime), 4 dr.; powdered opium, 1 dr.; soft soap, q. s. to make a paste. Applied to fungous ulcers.

=Caustic, Plunket's.= Upright crowfoot and lesser spear-wort, of each 1 oz.; sulphur, 5 scrup.; white arsenic (in very fine powder), 1 dr.; beat to a smooth paste, form it into balls, and dry them in the sun. In cancer; a portion of one of the balls is reduced to powder, which is mixed up with yelk of eggs, and applied on a piece of bladder.

=Caustic of Potassa with Lime.= _Syn._ VIENNA PASTE. Rub together equal parts of hydrate of potash and quick-lime, and keep the powder in a well-stoppered bottle.

=Caustic, Poten'tial.= Fused caustic potassa.

=Caustic, Recamier's.= See CAUSTIC, GOLDEN.

=Caustic, Sulphu''ric.= _Syn._ CAUSTICUM SULPHU''RICUM, C. AC'IDI SULPHU''RICI, L. _Prep._ 1. Plaster of Paris made into a paste with oil of vitriol.

2. Saffron, lint, or unsized paper, soaked in oil of vitriol, and triturated to a plastic mass.

=Caustic, Zinc.= _Syn._ CAUSTIC OF CHLORIDE OF ZINC, DR CANQUOIN'S CANCER CAUSTIC; CAUSTICUM ZINC'I, C. Z. CHLORID'I, L. _Prep._ 1. (Dr Canquoin.)--_a._ From chloride of zinc, 1 dr.; flour, 2 dr.; made into a stiff paste with water, q. s.

_b._ From chloride of zinc, 1 dr.; flour, 3 dr.; water, q. s.; as the last.

_c._ From chloride of zinc, 1 dr.; flour, 4 dr.; water, q. s.; as before.

_d._ From chloride of zinc, 2 dr.; chloride of antimony, 1 dr.; flour, 5 dr.; as before.

Powdered opium may be mixed with either of the preceding to mitigate the pain.

2. (Alex. Ure.) As above, but substituting plaster of Paris for the flour there ordered.

_Uses, &c._ As a caustic in cancer, lupus, skin-marks (_nævi_), &c. It is formed into small cakes or wafers not exceeding 1 or 2 lines in thickness, one of which is applied to the part, and allowed to remain on from 6 to 12 hours, when it is removed, and the part covered with a poultice. It produces an eschar, often exceeding a quarter of an inch in depth. The chlorides must be in the form of powder, and well mixed with the flour previously to adding the water. The last (No. 1, _d_) is recommended in nodulated cancerous tumours.

=CAUS'TICS (Ve'terinary).= In _veterinary practice_, any of the substances enumerated in the forgoing list may be employed; but nitric acid, sulphuric acid, carbolic acid, chloride of zinc, and nitrate of silver, are those most commonly used. See VETERINARY MEDICINES.

=CAV'IARE.= _Syn._ CAV'IAR, CAV'IALE. The salted roe of several species of sturgeon. It is much esteemed by the Russians, as well as by some other nations of northern Europe, and is occasionally eaten as a delicacy in this country. It is, however, very oily, indigestible, and unwholesome.

=CAYENNE'.= See CAPSICUM, PEPPERS.

=CEDAR-WOOD (Oil of).= See OILS.

=Cedar-Wood (Tincture of).= See TINCTURES.

=CE'DRAT.= See LIQUEURS.

=CE'DRENE= and =CE'DROLA=. The oil of cedar-wood, by careful distillation, is separable into two substances--a solid crystalline compound (_cedrola_), and a volatile liquid hydrocarbon (_cedrene_). The first may be converted into the other by distillation with phosphoric anhydride.

=CELLULARES.= In _botany_, a name given to cryptogams, or flowerless plants, upon the supposition that they consist entirely of cells.

=CEL'LULOSE.= See LIGNIN.

=CEMENT'.= _Syn._ CEMENT'TUM, L. Any substance which, when applied to the surfaces of other bodies, causes them to adhere together when placed in contact. Those referred to below are amongst the most useful preparations of this class. The term cement is also applied by builders and architects to several species of mortars and like compositions employed either to unite stones and bricks into masses, or as a protective covering against the weather or water, or to make statues, cornices, and similar ornamental articles.

In general the thinner the stratum of interposed cement, the stronger is the junction of the surfaces operated on. This caution is necessary, as in their anxiety to unite broken articles persons generally defeat themselves by spreading the cement too thickly on the edges of the fracture; whereas the least possible quantity should be used, so as to bring the edges as close as possible together.

=Cement, Al'abaster.= 1. Prom plaster of Paris (in fine powder), made into a cream with water, and at once applied.

2. Yellow resin, 2 parts; melt and stir in plaster of Paris, 1 part.

3. Yellow resin, beeswax, and plaster of Paris, equal parts.

4. Resin, 8 parts; wax, 1 part; melt and stir in plaster of Paris, 4 parts, or q. s.

5. Sulphur or shell-lac, melted with sufficient plaster of Paris or colouring matter to give the desired shade. Used to join or mend pieces in alabaster, white marble, Derbyshire spar, porphyry, and other like substances; and to fill up cracks, supply chips out of corners, &c. The last four are applied hot, the surfaces to be united having been previously warmed. See CEMENT, WATERGLASS.

=Cement, Architect'ural.= 1. From paper (reduced to a smooth paste by boiling it in water), sifted whiting, and good size, equal parts, boiled to a proper consistence.

2. Paper paste, size, and plaster of Paris, equal parts; as before.

_Obs._ This is a species of papier-maché. It is used to make architectural ornaments, busts, statues, columns, &c. It is very light, and receives a good polish, but will not stand the weather unless it is well varnished or painted.

=Cement, Arme'nian.= _Syn._ DIAMOND CEMENT, PERSIAN C., TURKISH C., JEWELLERS' C. The jewellers of Turkey, who are mostly Armenians, have a singular method of ornamenting watch-cases, &c., with diamonds and other precious stones, by simply gluing or cementing them on. The stone is set in silver or gold, and the lower part of the metal made flat, or to correspond with the part to which it is to be fixed; it is then gently warmed, and the glue is applied, which is so very strong that the parts thus cemented never separate. This glue will strongly unite pieces of glass and china, and even polished steel, and may be applied to a variety of useful purposes.

_Prep._ 1. (Original Armenian formula; Eton.) Dissolve five or six bits of gum mastic, each the size of a large pea, in as much rectified spirit of wine as will suffice to render it liquid; and, in another vessel, dissolve as much isinglass, previously a little softened in water (though none of the water must be used), in French brandy or good rum, as will make a two-ounce phial of very strong glue, adding two small bits of gum galbanum or ammoniacum, which must be rubbed or ground till they are dissolved. Then mix the whole with a sufficient heat. Keep the glue in a phial closely stopped, and when it is to be used set the phial in boiling water.

2. (Keller's ARMENIAN CEMENT.) Soak isinglass, 1/2 oz., in water, 4 oz., for 24 hours; evaporate in a water bath to 2 oz.; add rectified spirit, 2 oz., and strain through linen; mix this, whilst warm, with a solution formed by dissolving gum mastic (best), 1/4 oz., in rectified spirit, 2 oz.; add of powdered gum ammoniac 1 dr., and triturate together until perfectly incorporated, avoiding loss of the spirit by evaporation as much as possible.

3. (Ure's DIAMOND CEMENT.) Isinglass, 1 oz.; distilled water, 6 oz.; boil to 3 oz., and add rectified spirit, 1-1/2 oz.; boil for a minute or two, strain, and add, while hot, first a milky emulsion of ammoniac, 1/2 oz., and then tincture of mastic, 5 dr.

4. Isinglass soaked in water and dissolved in spirit, 2 oz. (thick); dissolve in this 10 gr. of very pale gum ammoniac (in tears), by rubbing them together; then add 6 large tears of gum mastic, dissolved in the least possible quantity of rectified spirit.

5. Isinglass dissolved in proof spirit (as _above_), 3 oz.; bottoms of mastic varnish (thick, but clear), 1-1/2 oz.; mix well.

_Obs._ When carefully made, this cement resists moisture and dries colourless. As usually met with, it is not only of very bad quality, but sold at exorbitant prices. "Some persons have sold a composition under the name of Armenian cement in England; but this composition is badly made; it is much too thin, and the quantity of mastic is much too small." (Eton.) Methylated spirit may be used instead of the pure spirit in the above preparations. Mastic and mastic varnish are also used by jewellers as cements.

=Cement, Beale's.= Chalk, 60 parts; lime and salt, of each 20 parts; Barnsey sand, 10 parts; iron filings or dust, and blue or red clay, of each 5 parts; grind together and calcine. Patented as a fire-proof cement.

=Cement, Boil'er.= _Prep._ Dried clay in powder, 6 lbs.; iron filings, 1 lb. Make into a paste with boiled linseed oil. Used to stop cracks and leaks in iron boilers, stoves, &c. See CEMENT, IRON, STEAM-BOILER C.

=Cement, Bot'any Bay.= Yellow gum (Botany Bay gum) and brickdust, equal parts, melted together. Used to cement coarse earthenware, &c.

=Cement, Bot'tle.= _Prep._ 1. Resin, 1 lb.; tallow or suet, 1/4 lb.; melt together, and stir in the colouring matter.

2. Resin, 5 lbs.; beeswax, 1 lb.; colouring, q. s.; as last.

3. (Red.) To each pound of the above add whiting (dry), 3 oz., and light red (burnt ochre), 4 oz.; or red bole, q. s. (all in fine powder).

4. (Black.)--_a._ To each pound of No. 1, or No. 2, add ivory black (bone black), q. s.

_b._ From black pitch, 6 lbs.; ivory black and whiting of each, 1 lb.; melted together. Used in the same way as common sealing-wax for bottle corks, cask bungs, &c. See CEMENT, MAISSIAT'S.

=Cement, Brim'stone.= Melted brimstone, either alone, or mixed with resin and brickdust. Cheap and useful.

=Cement, Bru'yere's.= Clay, 3 parts; slaked lime, 1 part; mix and expose them to a full red heat for 3 hours, then grind to powder. Recommended as an hydraulic cement.

=Cement, Build'ing.= _Syn._ ARTIFICIAL PUZZOLENE'. From a mixture of clay or loam, broken pottery, flints, or siliceous sand, or broken bottle glass, and wood ashes, exposed to a considerable heat in a furnace, until it becomes partially vitrified; it is then ground to fine powder, sifted, and mixed with one third its weight of quick-lime, also in fine powder, after which it must be packed (tight) in casks to preserve it from the air and moisture. For use it is mixed up with water and applied like Roman cement.

=Cement, Cap.= _Prep._ 1. Resin, 5 lbs.; beeswax and dried Venetian red, of each 1 lb.; melted together.

2. (C. G. Williams.) Equal weights of red lead and white lead. Used for chemical and electrical purposes. For cementing glass tubes, necks of balloons, &c., into metal mountings. No. 2 is preferable to white lead alone, and may be depended on for temperature up to 212°.

=Cement, Cheese.= From grated cheese, 2 parts; quick-lime (in fine powder) 1 part; white of egg, q. s.; beat to a paste. Used for earthenware, &c.

=Cement, Chem'ical.= _Syn._ SOFT CEMENT. _Prep._ From yellow wax, 4 parts; common turpentine, 2 parts; Venetian red (well dried), 1 part; melted together. Used as a temporary stopping or lute for the ends or joints of tubes, which are not exposed to much heat; as in alkalimetry, &c. See CEMENT, ELECTRICAL.

=Cement, Chi'nese.= _Syn._ SHELL-LAC CEMENT, LIQUID GLUE. _Prep._ 1. Finest pale orange shell-lac (broken small), 4 oz.; rectified spirit (strongest), 3 oz.; digested together in a corked bottle in a warm place until dissolved. Very strong and useful; almost odourless. It should have about the consistence of treacle.

2. As before, but using rectified wood naphtha as the solvent. Inferior to the last, but excellent for many purposes.

3. (Without spirit.) _Prep._ Borax, 1 oz.; water, 3/4 pint; shell-lac, 3 oz.; boil in a covered vessel until dissolved, then evaporate to a proper consistence. Cheap and useful, but dries slowly.

4. Macerate for several hours, 6 parts of glue, in small pieces, in 16 parts of water; then add 1 part of hydrochloric acid, and 1-1/2 part of sulphate of zinc; and let the mixture be kept for 10 or 12 hours at a temperature of 68° or 70° C.

_Uses, &c._ Employed to mend glass, china, fancy work, jewelry, &c., for which it is only inferior to Armenian cement. The first formula produces a cement so strong that pieces of wood may be joined together, cut slopingly across the grain, and will afterwards resist every attempt to break them at the same place. In many of the islands of the Indian Ocean, in Japan, China, and the East Indies, a similar cement is used to join pieces of wood for bows, lances, &c. The fluid is thinly smeared over each face of the joint, a piece of very thin gauze interposed, and the whole pressed tightly together and maintained so until the next day. Joints so made will even bear the continual flexure of a bow without separating. It is admirably adapted for fishing rods. The product of the second formula is commonly sold as LIQUID GLUE. That of the last is much used by the druggists and oilmen, instead of gum, for fixing paper labels to tin, and to glass when exposed to damp.

=Cement, Cop'persmiths'.= _Syn._ BLOOD CEMENT. From bullock's blood thickened with finely powdered quick-lime. Used to secure the edges and rivets of copper boilers, to mend leaks from joints, &c. It must be used as soon as mixed, as it rapidly gets hard. It is cheap and durable, and is suited for many other purposes.

=Cement, Curd.= _Prep._ 1. The curd of skimmed milk (obtained by the addition of vinegar or rennet) is beaten to a paste with quick-lime, in fine powder.

2. Add vinegar, 1/2 pint, to skimmed milk, 1/2 pint; mix the curd with the whites of 5 eggs; well beaten and powdered quick-lime, q. s. to form a paste. Used for mending glass and earthenware; they resist water and a moderate degree of heat.

3. Rub from two to four parts of the curd, with a cold solution of borax, till a thick liquid is obtained, that becomes clear on standing. This is an excellent cement for artificial meerschaums, and may be used to give consistency to silk goods, or to coat artificial flowers, and court plaster, to the latter of which it imparts more adhesiveness and firmness.

=Cement, Cut'lers'.= _Prep._ 1. Black resin, 4 lbs.; beeswax, 1 lb.; melt, and add finely powdered and well-dried brickdust, 1 lb.; mix well.

2. Equal weights of resin and brickdust, melted together.

_Use._ To fix knives and forks in their handles. It is put into the hollow of the handle, and the metal, previously made hot enough to melt the composition, pressed into its place whilst warm, and the whole kept upright and still until quite cold.

=Cement, Di'amond.= See CEMENT, ARMENIAN.

=Cement, Egg.= White of egg thickened with finely powdered quick-lime. Used to mend earthenware, glass, china, marble, alabaster, spar ornaments, &c. It does not resist long exposure to moisture unless it has been exposed to heat.

=Cement, Elas'tic.= _Prep._ 1. Caoutchouc (in small pieces), 1 part; chloroform, 3 parts; dissolve.

2. (Lenher.) Caoutchouc, 5 parts; chloroform, 3 parts; dissolve, and add gum mastic (powdered), 1 part. Elastic and transparent.

3. Gutta percha, 3 parts; caoutchouc, 1 part (both cut small); bisulphide of carbon, 8 parts; mix in a close vessel and dissolve by the heat of a water bath. This is to be gently warmed before it is applied.

4. Gutta percha, 1 lb.; caoutchouc, 4 oz.; pitch, 2 oz.; shell-lac, 1 oz.; linseed oil, 2 oz.; melted together. This must be melted before being applied.

_Obs._ The cements 1 and 2 are elastic and transparent, and are applicable to many uses. The others, 3 and 4, are used for uniting leather, cloth, &c.

=Cement, Elec'trical.= _Syn._ CHEMICAL CEMENT. From black resin, 7 lbs.; red ochre, 1 lb.; plaster of Paris, 1/2 lb. (both well dried and still warm); melted together, and the heat and agitation continued until all frothing ceases, and the liquid runs smooth; the vessel is then withdrawn from the fire, and the mixture stirred until cooled sufficiently. Used to cement the plates in galvanic troughs, join chemical vessels, &c. See CEMENT, CAP, CEMENT, SINGER'S, &c.

=Cement, Engineers''.= _Prep._ 1. Ground white lead, mixed with as much red lead as will make it of the consistence of putty.

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. Shell-lac, melted, and run into small sticks the size of a quill. Used to join glass, 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 assiduously 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 quantity 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, Glass.= _Syn._ GLASS 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 quantity 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 glass, wood, and even metal to each other. A good cement for fixing wood to glass may be made by dissolving isinglass in acetic acid, in such quantities 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. Shell-lac, melted and applied to the pieces slightly heated. Used to fix pieces of glass, &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, glass, &c. It is very tenacious, but long in drying.

=Cement, H[oe]nle's.= Shell-lac, 2 parts; Venice turpentine, 1 part; fused together, and formed into sticks. It is used like extemporaneous cement for glass 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 mass is obtained. This substance is much used as an imitation marble, as by polishing it with pumice stone, colouring it, and again polishing 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 substitute for meerschaum, which it much resembles."[238] See GAD'S, HAMELIN'S, and PARKER'S CEMENTS, &c.

[Footnote 238: 'Chemistry, Theoretical, Practical, and Analytical.']

=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 quantity 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 coarse 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 quantity of sal-ammoniac is increased a little, and a very small quantity 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 mass, 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 quantity 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, JAPANESE. _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 _antè_.)

=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 quantity 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 glass 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. Shell-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. Shell-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 glasses, stones, &c., while polishing 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 Baumé's hydrometer (_i.e._ sp. gr. 1·490 to 1·652), dissolve 3% of borax or sal-ammoniac; then add oxide of zinc which has been heated to redness, until the mass 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 glass, earthenware, &c. It is made into a paste with a little water, as wanted, and applied immediately.

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

=Cement, Park'er's.= This cement is made of the nodules of indurated and slightly ferruginous marl, called by mineralogists "septaria," and also of some other species of argillaceous limestone. These are burnt in conical kilns, with pit coal, in a similar way to other limestone, care being taken to avoid the use of too much heat, as if the pieces undergo the slightest degree of fusion, even on the surface, they will be unfit to form the cement. After being properly roasted the calx is reduced to a very fine powder by grinding, and immediately packed in barrels, to keep it from the air and moisture.