Chapter M: D’Arcet states the analysis of Marseilles soap at (18)

The construction of the bed will be seen by reference to the cross section _fig._ 1226. It consists of an iron or other metal roller _k_, _k_, turned to a truly cylindrical figure, and covered with cloth or leather, to afford a small degree of elasticity. This roller is mounted upon pivots in a frame _l_, _l_, and is supported by a smaller roller _m_, similarly mounted, which roller _m_, is intended merely to prevent any bending or depression of the central part of the upper roller or bed _k_, _k_, so that the cloth may be kept in close contact with the whole length of the cutting blades.

In order to allow the bed _k_ to rise and fall, for the purpose of bringing the cloth up to the cutters to be shorn, or lowering it away from them after the operation, the frame _l_, _l_, is made to slide up and down in the grooved standard _n_, _n_, the movable part enclosed within the standard being shown by dots. This standard _n_, is situated about the middle of the machine, crossing it immediately under the cutters, and is made fast to the frame _a_, by bolts and screws. There is a lever _o_, attached to the lower cross-rail of the standard, which turns upon a fulcrum-pin, the extremity of the shorter arm of which lever acts under the centre of the sliding-frame, so that by the lever _o_, the sliding-frame, with the bed, may be raised or lowered, and when so raised, be held up by a spring catch _j_.

It being now explained by what means the bed which supports the cloth is constructed, and brought up, so as to keep the cloth in close contact with the cutters, while the operation of shearing is going on; it is necessary, in the next place, to describe the construction of the cutters, and their mode of working; for which purpose, in addition to what is shown in the first three figures, the cutters are also represented detached, and upon a larger scale, in _fig._ 1227.

In this figure is exhibited a portion of the cutters in the same situation as in _fig._ 1221.; and alongside of it is a section of the same, taken through it at right angles to the former; _p_, is a metallic bar or rib, somewhat of a wedge form, which is fastened to the top part of the standard _a_, _a_, seen best in _fig._ 1220. To this bar a straight blade of steel _g_, is attached by screws, the edge of which stands forward even with the centre or axis of the cylindrical cutter _i_, and forms the ledger blade, or lower fixed edge of the shears. This blade remains stationary, and is in close contact with the pile or nap of the cloth, when the bed _k_, is raised, in the manner above described.

The cutter or upper blade of the shears, is formed by inserting two or more strips of plate steel _r_, _r_, in twisted directions, into grooves in the metallic cylinder _i_, _i_, the edges of which blades _r_, as the cylinder _i_ revolves, traverse along the edge of the fixed or ledger blade _g_, and by their obliquity produce a cutting action like shears; the edges of the two blades taking hold of the pile or raised nap, as the cloth passes under it, shaves off the superfluous ends of the wool, and leaves the face smooth.

Rotatory motion is given to the cutting cylinder _i_, by means of a band leading from the wheel _s_, which passes round the pulley fixed on the end of the cylinder _i_, the wheel _s_ being driven by a band leading from the rotatory part of a steam-engine, or any other first mover, and passed round the rigger _t_, fixed on the axle _s_. Tension is given to this band by a tightening pulley _u_, mounted on an adjustable sliding-piece _v_, which is secured to the standard by a screw; and this rigger is thrown in and out of geer by a clutch-box and lever, which sets the machine going, or stops it.

In order to give a drawing stroke to the cutter, which will cause the piece of cloth to be shorn off with better effect, the upper cutter has a slight lateral action, produced by the axle of the cutting cylinder being made sufficiently long to allow of its sliding laterally about an inch in its bearings; which sliding is effected by a cam _w_, fixed at one end. This cam is formed by an oblique groove, cut round the axle, (see _w_, _fig._ 1227.) and a tooth _x_, fixed to the frame or standard which works in it, as the cylinder revolves. By means of this tooth, the cylinder is made to slide laterally, a distance equal to the obliquity of the groove _w_, which produces the drawing stroke of the upper shear. In order that the rotation of the shearing cylinder may not be obstructed by friction, the tooth _x_, is made of two pieces, set a little apart, so as to afford a small degree of elasticity.

The manner of passing the cloth progressively under the cutters is as follows:--On the axle of the wheel _s_, and immediately behind that wheel, there is a small rigger, from which a band passes to a wheel _y_, mounted in an axle turning in bearings on the lower side-rail of the standard _a_. At the reverse extremity of this axle, there is another small rigger 1, from which a band passes to a wheel 2, fixed on the axle 3, which crosses near the middle of the machine, seen in _fig._ 1226. Upon this axle there is a sliding pulley 4, round which a cord is passed several times, whose extremities are made fast to the ends of the sliding carriage _d_; when, therefore, this pulley is locked to the axle, which is done by a clutch box, the previously described movements of the machine cause the pulley 4 to revolve, and by means of the rope passed round it, to draw the frame, with the cloth, slowly and progressively along under the cutters.

It remains only to point out the contrivance whereby the machinery throws itself out of geer, and stops its operations, when the edge of the cloth or list arrives at the cutters.

At the end of one of the habiting rails _h_, there is a stop affixed by a nut and screw 5, which, by the advance of the carriage, is brought up and made to press against a lever 6; when an arm from this lever 6, acting under the catch 7, raises the catch up, and allows the hand-lever 8, which is pressed upon by a strong spring, to throw the clutch-box 10, out of geer with the wheel 8; whereby the evolution of the machine instantly ceases. The lower part of the lever 6, being connected by a joint to the top of the lever _j_, the receding of the lever 6, draws back the lower catch _j_, and allows the sliding frame _l_, _l_, within the bed _k_, to descend. By now turning the lower rollers _e_, _e_, another portion of the cloth is brought up to be shorn; and when it is properly habited and strained, by the means above described, the carriage is slidden back, and, the parts being all thrown into geer, the operation goes on as before.

Mr. Hirst’s improvements in manufacturing woollen cloths, for which a patent was obtained in February, 1830, apply to that part of the process where a permanent lustre is given usually by what is called roll-boiling; that is, stewing the cloth, when tightly wound upon a roller, in a vessel of hot water or steam. As there are many disadvantages attendant upon the operation of roll-boiling, such as injuring the cloths, by overheating them, which weakens the fibre of the wool, and also changes some colours, he substituted, in place of it, a particular mode of acting upon the cloths, by occasional or intermitted immersion in hot water, and also in cold water, which operations may be performed either with or without pressure upon the cloth, as circumstances may require.

The apparatus which he proposes to employ for carrying on his improved process, is shown in the accompanying drawing. _Fig._ 1228. is a front view of the apparatus, complete, and in working order; _fig._ 1229. is a section, taken transversely through the middle of the machine, in the direction of _fig._ 1230.; and _fig._ 1230. is an end view of the same; _a_, _a_, _a_, is a vessel or tank, made of iron or wood, or any other suitable material: sloping at the back and front, and perpendicular at the ends. This tank must be sufficiently large to admit of half the diameter of the cylinder or drum _b_, _b_, _b_, being immersed into it, which drum is about four feet diameter, and about six feet long, or something more than the width of the piece of cloth intended to be operated upon. This cylinder or drum _b_, _b_, is constructed by combining segments of wood cut radially on their edges, secured by screw-bolts to the rims of the iron wheels, having arms, with an axle passing through the middle.

The cylinder or drum being thus formed, rendered smooth on its periphery, and mounted upon its axle in the tank, the piece of cloth is wound upon it as tightly as possible, which is done by placing it in a heap upon a stool, as at _c_, _fig._ 1229., passing its end over and between the tension-rollers _d_, _e_, and then securing it to the drum, the cloth is progressively drawn from the heap, between the tension-rollers, which are confined by a pall and ratchet, on to the periphery of the drum, by causing the drum to revolve upon its axis, until the whole piece of cloth is tightly wound upon the drum; it is then bound round with canvas or other wrappers, to keep it secure.

If the tank has not been previously charged with clean and pure water, it is now filled to the brim, as shown at _fig._ 1229., and opening the stopcock of the pipe _f_, which leads from a boiler, the steam is allowed to blow through the pipe, and discharge itself at the lower end, by which means the temperature of the water is raised in the tank to about 170° Fahr. Before the temperature of the water has got up, the drum is set in slow rotatory motion, in order that the cloth may be uniformly heated throughout; the drum making about one rotation per minute. The cloth, by immersion in the hot water, and passing through the cold air, in succession, for the space of about eight hours, gets a smooth soft face, the texture not being rendered harsh, or otherwise injured, as is frequently the case by roll-boiling.

Uniform rotatory motion to the drum is shown in _fig._ 1228., in which _g_ is an endless screw or worm, placed horizontally, and driven by a steam-engine or any other first mover employed in the factory. This endless screw takes into the teeth of, and drives, the vertical wheel _h_, upon the axle of which the coupling-box _i_, _i_, is fixed, and, consequently, continually revolves with it. At the end of the shaft of the drum, a pair of sliding clutches _k_, _k_, are mounted, which, when projected forward, as shown by dots in _fig._ 1228., produce the coupling or locking of the drum-shaft to the driving wheel, by which the drum is put in motion; but on withdrawing the clutches _k_, _k_, from the coupling-box _i_, _i_, as in the figure, the drum immediately stands still.

After operating upon the cloth in the way described, by passing it through hot water for the space of time required, the hot water is to be withdrawn by a cock at the bottom, or otherwise, and cold water introduced into the tank in its stead; in which cold water the cloth is to be continued turning, in the manner above described, for the space of twenty-four hours, which will perfectly fix the lustre that the face of the cloth has acquired by its immersion in the hot water, and leave the pile or nap, to the touch, in a soft silky state.

In the cold-water operation he sometimes employs a heavy pressing roller _l_, which, being mounted in slots in the frame or standard, revolve with the large drum, rolling over the back of the cloth as it goes round. This roller may be made to act upon the cloth with any required pressure, by depressing the screws _m_, _m_, or by the employment of weighted levers, if that should be thought necessary.

_Pressing_ is the last finish of cloth to give it a smooth level surface. The piece is folded backwards and forwards in yard lengths, so as to form a thick package on the board of a screw or hydraulic press. Between every fold sheets of glazed paper are placed to prevent the contiguous surfaces of cloth from coming into contact; and at the end of every twenty yards, three hot iron plates are inserted between the folds, the plates being laid side by side, so as to occupy the whole surface of the folds. Thin sheets of iron not heated are also inserted above and below the hot plates to moderate the heat. When the packs of cloth are properly folded, and piled in sufficient number in the press, they are subjected to a severe compression, and left under its influence till the plates get cold. The cloth is now taken out and folded again, so that the creases of the former folds may come opposite to the flat faces of the paper, and be removed by a second pressure. In finishing superfine cloths, however, a very slight pressure is given with iron plates but moderately warmed. The satiny lustre and smoothness given by strong compression with much heat is objectionable, as it renders the surface apt to become spotted and disfigured by rain.

WOOTZ, is the Indian name of steel.

WORT, is the fermentable infusion of malt or grains. See BEER.

WOULFE’S APPARATUS, is a series of vessels, connected by tubes, for the purpose of condensing gaseous products in water. See ACETIC ACID, _fig._ 1.; also MURIATIC ACID.

X.

XANTHINE, is the name given by Kuhlmann to the yellow dyeing-matter contained in madder.

Y.

YEAST, is the froth of fermenting worts. See BEER and FERMENTATION.

YELLOW DYE. (_Teinture jaune_, Fr.; _Gelbfarben_, Germ.) _Annotto_, _dyer’s-broom_ (_Genista tinctoria_), _fustic_, _fustet_, _Persian or French berries_, _quercitron bark_, _saw-wort_ (_Serratula tinctoria_), _turmeric_, _weld_, and _willow leaves_, are the principal yellow dyes of the vegetable kingdom; _chromate of lead_, _iron-oxide_, _nitric acid_ (for silk), _sulphuret of antimony_, and _sulphuret of arsenic_, are those of the mineral kingdom. Under these articles, as also under CALICO-PRINTING, DYEING, and MORDANTS, ample instructions will be found for communicating this colour to textile and other fibrous substances. Alumina and oxide of tin are the most approved bases of the above vegetable dyes. A nankin dye may be given with _bablah_, especially to cotton oiled preparatory to the Turkey-red process. See MADDER.

YELLOW, KING’S, is a poisonous yellow pigment. See ARSENIC and ORPIMENT.

YTTRIA, is a rare earth, extracted from the minerals gadolinite and yttrotantalite, being an oxide of the metal yttrium.

Z.

ZAFFRE. See COBALT.

ZEDOARY, is the root of a plant which grows in Malabar, Ceylon, &c. It occurs in wrinkled pieces, externally ash-coloured, internally brownish-red; possessed of a fragrant odour, somewhat resembling camphor; and of a pungent, aromatic, bitterish taste. It contains, according to Bucholz, 1·42 of volatile oil, of a burning camphorated taste; 3·60 of a soft, bitter, aromatic resin; 11·75 of a bitter aromatic extract, mixed with a little resin and potash-salts; 4·5 of gum; 9 of vegetable mucilage; 3·60 of starch; 8·0 of a starchy extract from the woody fibre, by means of caustic potassa, along with 31·2 of another matter, 12·89 of woody fibre, and 15 of water. According to Morin, this root, contains besides, an azotized substance, analogous to the extract of beef.

ZIMOME, is a principle supposed by Taddei to exist in the gluten of wheat-flour. Its identity is not recognised by later chemists.

ZIRCON. See HYACINTH and LAPIDARY.

ZIRCONIA, is a rare earth, extracted from the minerals zircon and hyacinth; it is an oxide of zirconium, a substance possessing externally none of the metallic characters, but resembling rather charcoal powder, which burns briskly, and almost with explosive violence.

ZINC, is a metal of a bluish-white colour, of considerable lustre when broken across, but easily tarnished by the air; its fracture is hackly, and foliated with small facets, irregularly set. It has little cohesion, and breaks in thin plates before the hammer, unless it has been previously subjected to a regulated process of lamination, at the temperature of from 220° to 300° F., whereby it becomes malleable, and retains its malleability and ductility afterwards. On this singular property, a patent was taken out by Messrs. Hobson and Sylvester, of Sheffield, many years ago, for manufacturing sheet zinc, for covering the roofs of houses, and sheathing ships; but the low price of copper at that time, and its superior tenacity, rendered their patent ineffective. The specific gravity of zinc varies from 6·9 to 7·2, according to the condensation it has received. It melts under a red heat, at about the 680th or 700th degree of Fahrenheit’s scale. When exposed to this heat with contact of air, the metal takes fire, and burns with a brilliant bluish-white light, while a few flocculi, of a woolly-looking white matter, rise out of the crucible, and float in the air. The result of the combustion is a white powder, formerly called flowers, but now oxide of zinc; consisting of 34 of metal, and 8 of oxygen, being their respective prime equivalents; or, in 100 parts, of 81 and 19.

The principal ores of zinc are, the sulphuret called _blende_, the silicate called _calamine_ and the sparry calamine, or the carbonate.

1. _Blende_ crystallizes in the garnet-dodecahedron; its fracture is highly conchoidal; lustre, adamantine; colours, black, brown, red, yellow, and green; transparent or translucent; specific gravity, 4. It is a simple sulphuret of the metal; and, therefore, consists, in its pure state, of 34 of zinc, and 16 of sulphur. It dissolves in nitric acid, with disengagement of sulphuretted hydrogen gas. It occurs in beds and veins, accompanied chiefly by galena, iron pyrites, copper pyrites, and heavy spar. There is a radiated variety found at Przibram, remarkable for containing a large proportion of cadmium. Blende is found in great quantities in Derbyshire and Cumberland, as also in Cornwall.

2. _Calamine_, or silicate of zinc, is divided into two species; the prismatic or electric calamine, and the rhomboidal; though they both agree in metallurgic treatment. The _first_ has a vitreous lustre, inclining to pearly; colour, white, but occasionally blue, green, yellow, or brown; spec. grav. 3·38. It often occurs massive, and in botroidal shapes. This species is a compound of oxide of zinc with silica and water; and its constituents are--zinc oxide, 66·37; silica, 26·23; water, 7·4; in 100 parts. Reduced to powder, it is soluble in dilute sulphuric or nitric acid, and the solution gelatinizes on cooling. It emits a green phosphorescent light before the blowpipe. The second species, or rhombohedral calamine, is a carbonate of zinc. Its specific gravity is 4·442, much denser than the preceding. It occurs in kidney-shaped, botroidal, stalactitic, and other imitative shapes; surface generally rough, composition columnar. Massive, with a granular texture, sometimes impalpable; strongly coherent. According to Smithson’s analysis, Derbyshire calamine consists of--oxide of zinc, 65·2; carbonic acid, 34·8; which coincides almost exactly with a prime equivalent of the oxide and acid, or 42 + 22 = 64.

The mineral genus called _zinc-ore_, or red oxide of zinc, is denser than either of the above, its spec. grav. being 5·432. It is a compound of oxide of zinc 88, and oxide of iron and manganese 12. It is found massive, of a granular texture, in large quantities, in several localities, in New Jersey. It is set free in several metallurgic processes, and occurs crystallized in six-sided prisms of a yellow colour, in the smelting-works of Kœnigshutte in Silesia, according to Mitscherlich.

The zinc ores of England, like those of France, Flanders, and Silesia, occur in two geological localities.

The first is in veins in the carboniferous or mountain limestone. The blende and the calamine most usually accompany the numerous veins of galena which traverse that limestone; though there are many lead mines that yield no calamine; and, on the other hand, there are veins of calamine alone, as at Matlock, whence a very considerable quantity of this ore is obtained.

In almost every point of England where that metalliferous limestone appears, there are explorations for lead and zinc ores. The neighbourhood of Alston-moor in Cumberland, of Castleton and Matlock in Derbyshire, and the small metalliferous belt of Flintshire, are peculiarly marked for their mineral riches. On the north side of the last county, calamine is mined in a rich vein of galena at Holywell, where it presents the singular appearance of occurring only in the ramifications that the lead vein makes from east to west, and never in those from north to south; while the blende, abundantly present in this mine, is found indifferently in all directions.

The second locality of calamine is in the magnesian limestone formation of the English geologists, the alpine limestone of the French, and the zechstein of the Germans. The calamine is disseminated through it in small contemporaneous veins, which, running in all directions, form the appearance of a network. These veins have commonly a thickness of only a few inches; but in certain cases they extend to four feet, in consequence of the union of several small ones into a mass. The explorations of calamine in the magnesian limestone, are situated chiefly on the flanks of the Mendip Hills, a chain which extends in a north-west and south-east direction, from the canal of Bristol to Frome. The calamine is worked mostly in the parishes of Phipham and Roborough, as also near Rickford and Broadfield-Doron, by means of a great multitude of small shafts. The miners pay, for the privilege of working, a tax of 1_l._ sterling per annum to the Lords of the Treasury; and they sell the ores, mixed with a considerable quantity of carbonate of lime, for 1_l._ per ton, at Phipham, after washing it slightly in a sieve. They are despatched to Bristol, where they receive a new washing, in order to separate the galena.

OF THE SMELTING OF THE ORES OF ZINC.

The greater part of the zinc works are situated in the neighbourhood of Birmingham and Bristol. The manufacture of brass, which has been long one of the staple articles of these towns, was probably the cause of the introduction of this branch of industry, at the period when brass began to be made by the direct union of copper with metallic zinc, instead of calamine. A few zinc furnaces exist also in the neighbourhood of Sheffield, amid the coal-pits surrounding that town. Bristol and Birmingham derive their chief supply of ores from the Mendip Hills and Flintshire; and Sheffield, from Alston-moor.

The calamine, freed from the galena by sorting with the hand, is calcined before its introduction into the smelting-furnaces, by being exposed, coarsely bruised, in reverberatory ovens, 10 feet long, and 8 broad, in a layer 6 inches thick. In some establishments the calcination is omitted, and the calamine, broken into pieces about the size of a pigeon’s egg, is mixed with its bulk of small coal.

Zinc is smelted in England, likewise from blende (sulphuret of zinc). This ore, after being washed, and broken into pieces of the size of a filbert, was sold a few years ago at the mine of Holywell for 3_l._ a ton, or half the price of calamine. It is roasted, without any other preparation, in reverberatory furnaces; which are about 8 feet wide, and 10 long; the distance between the roof and the sole being 30 inches, and the height of the fire-bridge 18. The layer of blende, which is placed on the hearth, is about 4 or 5 inches thick; and it is continually stirred up with rakes. One ton of it requires, for roasting, four tons of coals; and it suffers a loss of 20 per cent. The operation takes from 10 to 12 hours. The mixture of reducing consists of one-fourth part of the desulphuretted oxide, one-fourth of calcined calamine, and one-half part of charcoal; which affords commonly 30 per cent. of zinc.

The English furnaces for smelting zinc ores are sometimes quadrangular, sometimes round; the latter form being preferable. They are mounted with from 6 to 8 crucibles or pots (see _fig._ 1231.), arched over with a cupola _a_, placed under a conical chimney _b_, which serves to give a strong draught, and to carry off the smoke. In this cone there are as many doors _c_, _c_, _c_, as there are pots in the furnace; and an equal number of vents _d_, _d_, _d_, in the cupola, through which the smoke may escape, and the pots may be set. In the surrounding walls there are holes for taking out the pots, when they become unserviceable; after the pots are set, these holes are bricked up. The pots are heated to ignition in a reverberatory furnace before being set, and are put in by means of iron tong machinery supported upon two wheels, as is the case with glass-house pots, _e_, is the grate; _f_, the door for the fuel; _g_, the ash-pit. The pots _h_, _h_, _h_, have a hole in the centre of their bottom, which is closed with a wooden plug, when they are set charged with calamine, mixed with one-seventh of coal; which coal prevents the mixture from falling through the orifice, when the heat rises and consumes the plug. The sole of the hearth _i_, _i_, upon which the crucibles stand, is perforated under each of them, so that they can be reached from below; to the bottom orifice of the pot, when the distillation begins, a long sheet-iron pipe _k_, is joined, which dips at its end into a water-vessel _l_, for receiving in drops the condensed vapours of the zinc. The pot is charged from above, through an orifice in the lid of the pot, which is left open after the firing, till the bluish colour of the flame shows the volatilization of the metal; immediately whereupon the hole is covered with a fire-tile _m_. The iron tubes are apt to get obstructed during the distillation, and must therefore be occasionally cleared out with a redhot rod. When the distillation is finished, the iron pipes must be removed; the coaly and other contents of the pot cleared away. A pot lasts about four months upon an average. Five distillations may be made in the course of 14 days, in which from 6 to 10 tons of calamine may be worked up, and from 22 to 24 tons of coals consumed, with a product of two tons of zinc. The metal amounts to from 25 to 40 per cent. of the ore.

1, 2, is the level of the upper floor; 3, 4, level of the lower ceiling of the lower floor.

_Fig._ 1232., ground plan on the level of 1, 2: only one-half is here shown.

The zinc collected in this operation, is in the form of drops, and a very fine powder, mingled with some oxide. It must be melted in an iron pot or boiler, set in a proper furnace; and the oxide is skimmed off the surface, to be returned into the crucibles. The metal is, lastly, cast into square bars or ingots.

The crucibles are discharged at the end of each operation, by withdrawing the condenser, breaking with a rake the piece of charcoal which shuts their bottom, and then emptying them completely, by shaking their upper part. In replacing the condenser-pipe _k_ (see second pot from the right hand, _fig._ 1231), the flange at its top is covered with a ring of loam-lute, pressed against the conical bottom of the crucible, and secured in its place by means of two parallel rods _o_, _o_, which can be clamped by screws projecting horizontally from the vertical tunnel. See their places, indicated by two open dots near _o_, _o_.

A smelter and two labourers are employed in conducting a furnace; who make, with a mixture of equal parts of fire-clay, and cement of old pounds finely ground, the pots or crucibles, which last about four months. Five charges are made in 15 days; these work up from 6 to 10 tons of calamine, consume from 22 to 24 tons of coals, and produce 2 tons of zinc, upon an average. The following estimate of prices was made a few years ago:--

3 tons of calamine, at _£_6. _£_18 0 0
24 ditto coal, at 5_s._ 6 0 0
A smelter, at 2 guineas a week 2 2 0
Two labourers, each at 4_s._ per day 2 16 0
Incidental expenses 1 0 0
--------
_£_29 18 0

The calamine of Alston-moor, used at Sheffield, is not so rich; it produces at most only 25 per cent. of zinc. The coals are laid down at a cost of 5_s._ 8_d._ per ton; and the calamine laid down there 5_l._; whence the zinc will amount to 32_l._ 14_s._ per ton. The considerable importations of zinc from Belgium and Germany, for some years back, have caused a considerable fall in its price.

At Lüttich, where the calamine of Altenberg, near Aix-la-Chapelle, is smelted, a reduction furnace, containing long horizontal earthen tubes, is employed. The roasted calamine is finely ground, and mixed with from one-third to two-thirds its volume of coke or charcoal, broken to pieces the size of nuts.

_Fig._ 1233. represents this zinc furnace in elevation; and _fig._ 1234. in a vertical section through the middle. From the hearth to the bottom of the chimney it is 9 feet high, and the chimney itself is 18 or 20 feet high. _a_, is the ash-pit; _b_, the grate; _c_, the fireplace; _d_, the hearth; _e_, _e_, the laboratory; _f_, the upper arch, which closes in the laboratory; _f_, the second arch, which forms the hood-cap of the furnace; _g_, the chimney; _h_, the fire-wall, which rests against a supporting wall of the smelting-house. Through the vaulted hearth the flame of the fire draws through ten flues _i_, _i_, two placed in one line; betwixt these 5 pairs of draught openings, upon the sole of the hearth, the undermost earthen tubes _k_, immediately rest. The second and third rows of tubes _k_, _k_, lie in a parallel direction over each other, at about one inch apart; in the sixth row there are only two tubes; so that there are 22 tubes altogether in one furnace. At their two ends these tubes rest upon fire-tiles, which form, with the side-walls, a kind of checquer-work _l_, _l_. The tubes are 4 feet long, 4 to 5 inches in diameter within, 5/4 of an inch thick. The fire, which arrives at the laboratory through the flues _i_, _i_, plays round the tubes, and passes off through the apertures _m_, _m_, in both arches of the furnace, into the chimney. _n_, is an opening in the front wall between the two arches, which serves to modify the draught, by admitting more or less of the external air.

The two slender side walls _o_, _o_, of the furnace, are a foot distant from the chequer-work, so that on the horizontal iron bars _q_, _q_, supported by the hooks _p_, _p_, the iron receivers _r_, _r_, may have room to rest at their fore part. These receivers are conical pipes of cast iron, 1-1/2 foot long, posteriorly 1-1/2 inch, and anteriorly 1 inch wide at the utmost. After the earthen tubes have been filled with the ore to be smelted, these conical pipes are luted to them in a slightly slanting position. These cones last no more than three weeks; and are generally lengthened with narrow-mouthed wrought-iron tubes, to prevent the combustion of the zinc, by contact of air. When the furnace is in activity, a blue flame is to be seen at the mouths of all these pipes. Every two hours the liquefied metal is raked out into a shovel placed beneath; and in 12 hours the charge is distilled; after which the tubes are cleared out, and re-charged. 100 pounds of metallic zinc are the product of one operation. It is remelted at a loss of 10 per cent., and cast into moulds for sale.

_Fig._ 1235. is a longitudinal section of the furnace for calcining calamine in Upper Silesia; _fig._ 1236. is a ground-plan of the furnace. _a_, is the orifice in the vault or dome, for the introduction of the ore; _b_, _b_, apertures in the side-walls, shut with doors, through which the matter may be turned over; _c_, the chimney; _d_, the fire-bridge; _e_, the grate; _f_, the feed opening of the fire, the fuel being pitcoal. The calamine is stirred about every hour; and after being well calcined during 5 or 6 hours, it is withdrawn; and a new charge is put in. These Silesian furnaces admit of 30 cwt. at a time; and for roasting every 100 cwt. 15 Prussian bushels of fuel, equal to 23 English bushels, are employed. These calcining furnaces are sometimes built alongside of the zinc smelting-furnaces, and are heated by the waste flame of the latter. The roasting is performed in the Netherlands in shafts, like small blast iron-furnaces, called schachtofen.

The hearth _a_, in _figs._ 1237, 1238., is constructed for working with 5 muffles, one of which is long, and four short. The muffles are made upon moulds, of fire-clay mixed with ground potsherds. The receivers are stoneware bottles. The grate is 10 inches beneath the level of the hearth. _b_, the fire-bridge, is proportionally high, to diminish the force of the flame upon the hearth, that it may not strike the muffles. _c_, is the opening through which the muffles are put in and taken out; during the firing it is partly filled with bricks, so that the smoke and flame may escape between them; _d_, _d_, are openings for adjusting the positions of the muffles; _e_, cross hoops of iron, to strengthen the brick arch; _f_, is a bed of sand under the sole of the hearth. During the first two days, the fire is applied under the grating; the heat must be very slowly raised to redness, at which pitch it must be maintained during two days. From 8 to 10 days are required for the firing of the muffles.

The furnace shown in _figs._ 1239, 1240, 1241. is for the melting of the metallic zinc. _Fig._ 1240. is a front view; _fig._ 1239. a transverse section; _fig._ 1241. a view from above: _a_, is the fire-door; _b_, the grate; _c_, the fire-bridge; _d_, the flue; _e_, the chimney; _f_, _f_, _f_, cast-iron melting-pots, which contain each about 10 cwt. of the metal. The heat is moderated by the successive addition of pieces of cold zinc. The inside of the pots should be coated with loam, to prevent the iron being attacked by the zinc. When the zinc is intended to be laminated, it should be melted with the lowest possible heat, and poured into hot moulds.

When the zinc ores contain cadmium, this metal distils over in the form of brown oxide, with the first portions, being more volatile than zinc.

Under BRASS and COPPER, the most useful alloys of zinc are described. The sulphate, vulgarly called white vitriol, is made from the sulphuret, by roasting it gently, and then exposing it upon sloping terraces to the action of air and moisture, as has been fully detailed under SULPHATE OF IRON. The purest sulphate of zinc is made by dissolving the metal in dilute sulphuric acid, digesting the solution over some of the metal, filtering, evaporating, and crystallizing.

Sulphate of zinc is added as a drier to japan varnishes.

The ordinary zinc found in the market is never pure; but contains lead, cadmium, arsenic, copper, iron, and carbon; from some of which, it may be freed in a great degree by distillation; but even after this process it retains a little lead, with all the arsenic and cadmium. The separation of the latter is described under CADMIUM. Zinc, free from other metals, may be obtained by distilling a mixture of charcoal and its subcarbonate, precipitated from the crystallized sulphate by carbonate of soda. By holding a porcelain saucer over the flame of hydrogen produced from the action of dilute sulphuric acid upon any sample of the zinc of commerce, the presence of arsenic in it may be made manifest by the deposit of a gray film of the latter metal. Antimony, however, produces a somewhat similar effect to arsenic.

Zinc is extensively employed for making water-cisterns, baths, spouts, pipes, plates for the zincographer, for voltaic batteries, filings for fire-works, covering roofs, and a great many architectural purposes, especially in Berlin; because this metal, after it gets covered with a thin film of oxide or carbonate, suffers no further change by long exposure to the weather. One capital objection to zinc as a roofing material, is its combustibility.

Chloride of zinc has been recently used with great advantage as an escharotic for removing cancerous tumours, and healing various ill-constitutioned ulcers. It, as also the nitrate, forms an ingredient in the resist pastes for the pale blues of the indigo vat.

Spelter (zinc) imported for home consumption--in 1835, 52,604 cwts.; in 1836, 47,406 cwts. Duty,--in cakes, 2_s._; not in cakes, 10_s._ per cwt.

THE END.

LONDON:
Printed by A. SPOTTISWOODE
New-Street-Square

Alphabetical List of Articles.

ABB-WOOL -- ACETATE -- ACETATE OF ALUMINA -- ACETIC ACID -- ACETIMETER -- ACETONE -- ACID OF ARSENIC -- ACIDS -- ACROSPIRE -- ADDITIONS -- ADIPOCIRE -- ADIT -- ADULTERATION -- ÆTHER -- AFFINITY -- AGARIC -- AGATE -- AIR -- ALABASTER -- ALBUM GRÆCUM -- ALCARAZZAS -- ALCOHOL -- ALE -- ALEMBIC -- ALEMBROTH -- ALGAROTH -- ALIZARINE -- ALKALI -- ALKALIMETER -- ALKANA -- ALKANET -- ALLIGATION -- ALLOY -- ALMOND -- ALMOND OIL -- ALOE -- ALUDEL -- ALUM -- AMADOU -- AMALGAM -- AMALGAMATION -- AMBER -- AMBERGRIS -- AMIANTHUS -- AMMONIA -- AMMONIAC -- AMORPHOUS -- ANALYSIS -- ANCHOR -- ANIMÉ -- ANKER -- ANNEALING or NEALING -- ANNOTTO -- ANTHRACITE -- ANTIGUGGLER -- ANTIMONY -- ANTISEPTICS -- ANVIL -- AQUA REGIA -- AQUA VITÆ -- AQUAFORTIS -- ARCHIL -- ARDENT SPIRIT -- AREOMETER OF BAUMÉ -- ARGILLACEOUS EARTH -- ARGOL -- ARMS -- ARRACK -- ARROW ROOT -- ARSENIC -- ARTESIAN WELLS -- ASPHALTUM -- ASSAY and ASSAYING -- ATOMIC WEIGHTS or ATOMS -- ATTAR OF ROSES -- AURUM MUSIVUM -- AUTOMATIC -- AUTOMATON -- AXE -- AXLES -- AXUNGE -- AZOTIZED -- AZURE

BABLAH -- BAGASSE -- BAKING -- BALANCE -- BALSAMS -- BANDANNA -- BARBERRY -- BARILLA -- BARIUM -- BARK OF OAK -- BARLEY -- BARM -- BARYTA or BARYTES -- BASSORINE -- BATHS -- BDELLIUM -- BEER -- BEET-ROOT SUGAR -- BELL-METAL -- BELLOWS -- BEN OIL -- BENGAL STRIPES -- BENJAMIN or BENZOIN -- BERLIN BLUE -- BERRIES OF AVIGNON -- BERYL -- BEZOAR -- BILE -- BIRDLIME -- BISMUTH -- BISTRE -- BITTER PRINCIPLE -- BITUMEN, or ASPHALTUM -- BLACK DYE -- BLACK PIGMENT -- BLEACHING -- BLENDE -- BLOCK MANUFACTURE -- BLOOD -- BLOWING MACHINE -- BLOWPIPE -- BLUE DYES -- BLUE PIGMENTS -- BLUE VITRIOL -- BOMBAZINE -- BONE BLACK -- BONES -- BOOKBINDING -- BORAX -- BOTTLE MANUFACTURE -- BOUGIE -- BRACES -- BRAIDING MACHINE -- BRAN -- BRANDY -- BRASS -- BRAZIL-WOOD -- BRAZING -- BREAD -- BRECCIA -- BREWING -- BRICK -- BRIMSTONE -- BRITISH GUM -- BROMINE -- BRONZE -- BROWN DYE -- BRUSHES -- BUTTER -- BUTTER OF CACAO -- BUTTON MANUFACTURE

CABLE -- CACAO, BUTTER OF -- CADMIUM -- CAFEINE -- CAJEPUT OIL -- CALAMANCO -- CALAMINE -- CALC-SINTER -- CALC-TUFF -- CALCAREOUS EARTH -- CALCAREOUS SPAR -- CALCEDONY -- CALCHANTUM -- CALCINATION -- CALCIUM -- CALCULUS -- CALENDER -- CALICO-PRINTING -- CALOMEL -- CALORIC -- CALORIFÈRE OF WATER -- CAMBRIC -- CAMLET OR CAMBLET -- CAMPHOR, or CAMPHIRE -- CAMWOOD -- CANDLE -- CANE-MILL -- CANNON -- CANVASS -- CAOUTCHOUC, GUM-ELASTIC, OR INDIAN-RUBBER -- CAPERS -- CAPSTAN -- CARAT or CARACT -- CARBON -- CARBONATE OF AMMONIA -- CARBONATED WATER -- CARBONATES -- CARBONIC ACID -- CARBONIC OXIDE -- CARBUNCLE -- CARBURET OF SULPHUR -- CARBURETTED HYDROGEN -- CARD CUTTING -- CARDS -- CARDS, PLAYING -- CARMINE -- CARPET -- CARTHAMUS -- CASE-HARDENING -- CASHMERE or CACHEMERE -- CASK -- CASSAVA -- CASSIS -- CASTING OF METALS -- CASTOR -- CASTOR OIL -- CASTOR or CASTOREUM -- CASTORINE -- CATECHU -- CATGUT -- CATHARTINE -- CAUSTIC -- CAVIAR -- CAWK -- CEDRA -- CELESTINE -- CEMENTATION -- CEMENTS -- CERASIN -- CERATE -- CERINE -- CERIUM -- CERUSE -- CETINE -- CHAINWORK -- CHALK -- CHALK--Black -- CHALK--French -- CHALK--Red -- CHARCOAL -- CHICA -- CHIMNEY -- CHINTZ -- CHLORATE OF POTASH -- CHLORATES -- CHLORIC ACID -- CHLORINE -- CHLOROMETRY -- CHOCOLATE -- CHROMATES -- CHROMIC ACID -- CHROMIUM -- CINNABAR -- CINNAMON -- CITRIC ACID -- CIVET -- CLAY -- CLOTH-BINDING -- CLOTH, MANUFACTURE OF -- COBALT -- COCCULUS INDICUS, or Indian berry -- COCHINEAL -- COCOA, STEARINE, AND ELAINE -- COFFEE -- COKE -- COLCOTHAR OF VITRIOL -- COLOPHANY -- COLOURING MATTER -- COLUMBIUM -- COLZA -- COMB -- COMBINATION -- COMBUSTIBLE -- COMBUSTION -- COMPOUND COLOURS -- CONCRETE -- CONGELATION -- COOLING OF FLUIDS -- COPAL -- COPPER -- COPPER, Statistics of -- COPPERAS -- CORAL -- CORK -- CORROSIVE SUBLIMATE -- CORUNDUM; or Telesie -- COTTON DYEING -- COTTON MANUFACTURE -- COURT PLASTER -- CRAPE -- CRAYONS -- CRAYONS, lithographic -- CREOSOTE -- CRUCIBLES -- CRYSTAL -- CUDBEAR -- CUPELLATION -- CURRYING OF LEATHER -- CUTLERY -- CYANATES -- CYANHYDRIC Acid -- CYANIDES -- CYANIDES, FERRO -- CYANOGEN -- CYDER

DAHLINE -- DAMASCUS BLADES -- DAMASK -- DAMASKEENING -- DAMASSIN -- DAMPS -- DAPHNINE -- DATOLITE -- DECANTATION -- DECOCTION -- DECOMPOSITION -- DECREPITATION -- DEFECATION -- DEFLAGRATION -- DELIQUESCENT -- DELPHINIA -- DEPHLEGMATION -- DEPHLOGISTICATED -- DEPILATORY -- DETONATION -- DEUTOXIDE -- DEXTRINE -- DIAMOND -- DIAMOND MICROSCOPES -- DIAMONDS, cutting of -- DIAPER -- DIASTASE -- DIES FOR STAMPING -- DIGESTER -- DIMITY -- DISTILLATION -- DOCIMACY -- DORNOCK -- DRAGON’S BLOOD -- DRUGGET -- DRYING HOUSE -- DUCTILITY -- DUNGING -- DYEING

EARTHS -- EAU DE COLOGNE -- EAU DE LUCE -- EBULLITION -- EDGE-TOOLS -- EDULCORATE -- EFFERVESCENCE -- EFFLORESCENCE -- EGGS, HATCHING -- EIDER-DOWN -- ELAINE -- ELASTIC BANDS -- ELECTIVE AFFINITY -- ELEMENTS -- ELEMI -- ELUTRIATE -- EMBALMING -- EMBOSSING CLOTH -- EMBOSSING WOOD -- EMBROIDERING MACHINE -- EMERALD -- EMERY -- EMPYREUMA -- ENAMELS -- EPSOM SALTS -- EQUIVALENTS, CHEMICAL -- ESSENCE D’ORIENT -- ESSENCES -- ETCHING Varnish -- ETHER -- ETHER, Acetic -- ETHIOPS -- EUDIOMETER -- EVAPORATION -- EXPANSION -- EXTRACTS

FAHLERZ -- FAINTS -- FAN -- FARINA -- FATS -- FAULTS -- FEATHERS -- FECULA -- FELSPAR -- FELTING -- FERMENT -- FERMENTATION -- FERROCYANATE, or, FERROCYANIDE -- FERROPRUSSIATES -- FIBRE, VEGETABLE -- FIBRINE -- FILE -- FILLIGREE -- FILTRATION -- FIRE ARMS, MANUFACTURE OF -- FIRE-DAMP -- FIRE-WORKS -- FISH-HOOKS -- FLAKE WHITE -- FLAME -- FLANNEL -- FLAX -- FLINT -- FLOSS -- FLOSS-SILK -- FLOUR -- FLOUR OF WHEAT, Adulterations of, to Detect -- FLOWERS -- FLOWERS, ARTIFICIAL, MANUFACTURE OF -- FLUATES -- FLUOR SPAR -- FLUX -- FLY POWDER -- FODDER -- FONDUS -- FORGE -- FORMIATES -- FORMIC ACID -- FORMULÆ, CHEMICAL -- FOUNDING -- FOUNTAIN -- FOXING -- FRANKFORT BLACK -- FREEZING -- FRENCH BERRIES -- FRICTION, counteraction of -- FRIT -- FUEL -- FULGURATION -- FULLER’S EARTH -- FULLING -- FULLING MILL -- FULMINATES -- FULMINIC ACID -- FUMIGATION -- FUR -- FURNACE OF ASSAY -- FUSIBILITY -- FUSIBLE METAL -- FUSTET -- FUSTIAN -- FUSTIC

GABRONITE -- GADOLINITE -- GALACTOMETER, or LACTOMETER -- GALBANUM -- GALENA -- GALIPOT -- GALL OF ANIMALS, or OX-GALL, purification of -- GALL OF GLASS -- GALL-NUTS, or GALLS -- GALLATES -- GALLIC ACID -- GALLIPOLI OIL -- GALVANIZED IRON -- GAMBOGE -- GANGUE -- GARNET -- GAS -- GAS-HOLDER -- GAS-LIGHT -- GASOMETER -- GAUZE WIRE CLOTH -- GAY-LUSSITE -- GELATINE -- GEMS -- GEOGNOSY -- GERMAN SILVER -- GERMINATION -- GIG MACHINES -- GILDING -- GIN, or Geneva, -- GINNING -- GLANCE COAL -- GLASS -- GLASS CUTTING AND GRINDING -- GLASS MAKING -- GLAUBER SALT -- GLAZES -- GLAZIER -- GLOVE MANUFACTURE -- GLOVE-SEWING -- GLUCINA -- GLUE -- GLUTEN -- GLYCERINE -- GNEISS -- GOLD -- GONG-GONG; or tam-tam -- GONIOMETER -- GRADUATOR -- GRANITE -- GRANULATION -- GRAPHITE -- GRAUWACKE or GREYWACKE -- GRAY DYE -- GREEN DYE -- GREEN PAINTS -- GREEN VITRIOL -- GUAIAC -- GUANO -- GUM -- GUM RESINS -- GUNPOWDER -- GYPSUM

HADE -- HAIR -- HAIR PENCILS OR BRUSHES -- HALOGENE -- HANDSPIKE -- HARDNESS -- HARTSHORN, SPIRIT OF -- HAT MANUFACTURE -- HATCHING OF CHICKENS -- HEALDS -- HEARTH -- HEAT -- HEAT-REGULATOR -- HEAVY SPAR -- HECKLE -- HELIOTROPE -- HEMATINE -- HEMATITE -- HEMP -- HEPAR -- HEPATIC AIR -- HERMETICAL SEAL -- HIDE -- HIRCINE -- HOG’s LARD -- HONEY -- HONEY-STONE -- HOP -- HORDEINE -- HORN -- HORNSILVER -- HORNSTONE -- HORSE POWER -- HOSIERY -- HOT-FLUE -- HYDRATES -- HYDRAULIC PRESS -- HYDRIODIC ACID -- HYDROCHLORIC ACID -- HYDROGEN -- HYDROMETER -- HYDROSULPHURETS -- HYMEN[OE]A COURBARIL -- HYOSCIAMUS NIGER -- HYPEROXYMURIATES -- HYPOSULPHATES; HYPOSULPHITES

ICEHOUSE -- IMPERMEABLE -- INCOMBUSTIBLE CLOTH -- INCUBATION, ARTIFICIAL -- INDIAN RUBBER -- INDIGO -- INK -- INULINE -- IODINE -- IRIDIUM -- IRON -- ISINGLASS, or Fish-glue -- ISLAND MOSS -- IVORY -- IVORY BLACK

JACK -- JACK and JACK-SINKERS -- JACK-BACK -- JACQUARD -- JADE -- JAPANNING -- JASPER -- JELLY, ANIMAL -- JELLY, VEGETABLE -- JET -- JEWELLERY, Art of.

KALI -- KAOLIN -- KARABÉ -- KELP -- KERMES -- KILLAS -- KILN -- KINIC ACID -- KINO -- KIRSCHWASSER -- KNOPPERN -- KOUMISS

LABDANUM or LADANUM -- LABRADORITE, OPALINE or LABRADORE FELSPAR -- LABYRINTH -- LAC, LAC-DYE -- LACCIC ACID -- LACCINE -- LACE MANUFACTURE -- LACQUER -- LACTIC ACID -- LACTOMETER -- LAKES -- LAMINABLE -- LAMIUM ALBUM -- LAMP OF DAVY -- LAMP-BLACK -- LAMPATES and LAMPIC ACID -- LAMPS -- LAPIDARY, Art of -- LAZULITE -- LEAD -- LEAD-SHOT -- LEATHER -- LEDUM PALUSTRE -- LEGUMINE -- LEMONS -- LEUCINE -- LEUCITE -- LEVIGATION -- LEWIS -- LIAS -- LIBAVIUS, LIQUOR OF -- LICHEN. -- LIGNEOUS MATTER -- LIGNITE -- LILAC DYE -- LIMESTONE -- LINEN -- LINSEED -- LIQUATION -- LIQUEURS, LIQUORISTE -- LIQUID AMBER -- LITHARGE -- LITHIA -- LITHIUM -- LITHOGRAPHY -- LITMUS -- LIXIVIATION -- LOADSTONE, MAGNETIC IRON-STONE -- LOAM -- LODE -- LOGWOOD -- LOOM -- LUBRICATION -- LUPININE -- LUPULINE -- LUTE -- LUTEOLINE -- LYCOPODIUM CLAVATUM -- LYDIAN STONE

MACARONI -- MACE -- MACERATION -- MACLE -- MADDER -- MADREPORES -- MAGISTERY -- MAGISTRAL -- MAGMA -- MAGNANIER -- MAGNESIA -- MAGNESIA, NATIVE -- MAGNESIAN LIMESTONE -- MAGNESITE -- MAGNET, NATIVE -- MAHALEB -- MALACHITE -- MALATES -- MALIC ACID -- MALLEABILITY -- MALT -- MALT KILN -- MALTHA -- MANGANESE -- MANGLE -- MANIOC -- MANNA -- MARBLE -- MARCASITE -- MARGARATES -- MARGARIC ACID -- MARINE ACID -- MARINE SALT -- MARL -- MARQUETRY -- MARTIAL -- MASSICOT -- MASTIC -- MATRASS -- MATTE -- MEADOW ORE -- MEDALS -- MEERSCHAUM -- MELLITE -- MELLITIC ACID -- MELLON -- MENACHANITE -- MERCURY or QUICKSILVER -- MERCURY, BICHLORIDE OF -- MERCURY, PROTOCHLORIDE OF -- METALLURGY -- METALS -- METEORITES -- METHYLÈNE -- MICA -- MICROCOSMIC SALT -- MILK -- MILL-STONE, or BUHR-STONE -- MINERAL WATERS -- MINES -- MINIUM -- MINT -- MIRRORS -- MISPICKEL -- MOHAIR -- MOIRÉE METALLIQUE -- MOLASSE -- MOLASSES -- MOLYBDENUM -- MORDANT (adhesive) -- MORDANT (colouring) -- MOROCCO -- MORPHIA -- MORTAR, HYDRAULIC -- MOSAIC -- MOSAIC GOLD -- MOTHER OF PEARL -- MOTHER-WATER -- MOUNTAIN SOAP -- MUCIC ACID -- MUCILAGE -- MUFFLE -- MUNDIC -- MUNJEET -- MURIATES -- MURIATIC or HYDROCHLORIC ACID -- MUSK -- MUSLIN -- MUST -- MUSTARD -- MUTAGE -- MYRICINE -- MYRRH

NACARAT -- NAILS, MANUFACTURE OF -- NANKIN -- NAPHTHA, or ROCK-OIL -- NAPHTHALINE -- NAPLES YELLOW -- NATRON -- NEALING -- NEB-NEB -- NEEDLE MANUFACTURE -- NEROLI -- NET -- NEUTRALIZATION -- NICARAGUA WOOD -- NICKEL -- NICOTIANINE -- NICOTINE -- NITRATE OF AMMONIA -- NITRATE OF LEAD -- NITRATE OF POTASH -- NITRATE OF SILVER -- NITRATE OF SODA -- NITRATE OF STRONTIA -- NITRIC ACID -- NITRO-MURIATIC ACID -- NITROGEN GAS, or AZOTE -- NITROGEN, DEUTOXIDE OF -- NITROGEN, PROTOXIDE OF -- NITROUS ACID -- NOPAL -- NUT OIL -- NUTMEG -- NUX VOMICA

OAK BARK -- OATS -- OBSIDIAN -- OCHRE -- OIL OF VITRIOL -- OILS -- OILS, VOLATILE OR ESSENTIAL; Manufacture of -- OLEATES -- OLEFIANT GAS -- OLEIC ACID -- OLEINE -- OLIBANUM -- OLIVE OIL -- ONYX -- OOLITE -- OOST, or OAST -- OPAL -- OPERAMETER -- OPIUM -- OPOBALSAM -- OPOPONAX -- ORANGE DYE -- ORCINE -- ORES -- ORPIMENT -- ORYCTNOGNOSY -- OSMIUM -- OSTEOCOLLA -- OXALATES -- OXALIC ACID -- OXIDES -- OXISELS -- OXYGEN

PACKFONG -- PACO, or PACOS -- PADDING MACHINE -- PAINT -- PAINTS, GRINDING OF -- PAINTS, VITRIFIABLE -- PALLADIUM -- PALM OIL -- PAPER CUTTING -- PAPER-HANGINGS -- PAPER, MANUFACTURE OF -- PARAFFINE -- PARCHMENT -- PARTING -- PASTEL (colour) -- PASTEL (crayon) -- PASTES, or FACTITIOUS GEMS -- PASTILLE (perfumery) -- PASTILLE (tablet) -- PE-TUNT-SE -- PEARLASH -- PEARLS -- PEARLS, ARTIFICIAL -- PEARLWHITE -- PECTIC ACID -- PECTINE -- PELTRY -- PENCIL MANUFACTURE -- PENS, STEEL -- PEPPER -- PERFUMERY, ART OF -- PERRY -- PERSIAN BERRIES -- PETROLEUM -- PEWTER, PEWTERER -- PHOSPHORIC ACID -- PHOSPHORUS -- PICAMARE -- PICROMEL -- PICROTOXINE -- PIGMENTS, VITRIFIABLE -- PIMENTO -- PIN MANUFACTURE -- PINCHBECK -- PINE-APPLE YARN and CLOTH -- PINEY TALLOW -- PIPERINE -- PITCH of wood-tar -- PITCH, MINERAL -- PITCOAL -- PITCOAL, COKING OF -- PITTACALL -- PLASTER -- PLASTER OF PARIS -- PLATED MANUFACTURE -- PLATINA-MOHR -- PLATINUM -- PLUMBAGO -- PLUSH -- POINT NET -- PORCELAIN -- PORPHYRY -- PORTER -- PORTLAND STONE -- POTASH, or POTASSA -- POTASSIUM -- POTATO -- POTTERY, PORCELAIN. -- PRECIPITATE -- PRECIPITATION -- PRESS, HYDRAULIC -- PRINCE’S METAL, or Prince Rupert’s metal -- PRINTING INK -- PRINTING MACHINE -- PRUSSIAN BLUE, and PRUSSIATE OF POTASH -- PUMICE-STONE -- PUOZZOLANA -- PURPLE OF CASSIUS, Gold purple -- PURPLE OF MOLLUSCA -- PURPURIC ACID -- PURPURINE -- PUTREFACTION and its prevention -- PYRITES -- PYRO-ACETIC SPIRIT -- PYROLIGNOUS ACID -- PYROLIGNOUS or PYROXILIC SPIRIT -- PYROMETER -- PYROPHORUS -- PYROTECHNY -- PYROXILINE

QUARTATION -- QUARTZ -- QUASSIA -- QUEEN’s WARE -- QUEEN’s YELLOW -- QUERCITRON -- QUICKLIME -- QUICKSILVER -- QUILL -- QUININA -- QUINTESSENCE

RAISINS -- RAPE-SEED -- RASP, MECHANICAL -- RATAFIA -- REALGAR -- RECTIFICATION -- RED LIQUOR -- REED -- REFINING OF GOLD AND SILVER -- REFRIGERATION OF WORTS, &c. -- REGULUS -- RESIN, KAURI or COWDEE -- RESINS -- RETORT -- REVERBERATORY FURNACE -- RHODIUM -- RIBBON MANUFACTURE -- RICE -- RICE CLEANING -- RIFLE -- RINSING MACHINE -- ROCKETS -- ROLLING-MILL -- ROPE-MAKING -- ROSIN GAS -- ROSIN, or COLOPHANY -- ROTTEN-STONE -- ROUGE -- RUBY -- RUM -- RUST -- RYE