■ 174 ■ Class 1.—MINING AND MINERAL PRODUCTS. [United
South Side.—Areas S. 1 to S. 27.
[The produce of the Snailbeacli Mines since 1845 hasbeen as follows:—
Years.
Lead Ores.Tons.
Lead.
Tons.
1845
3,000
2,000
1846
3,852
2,700
1847
3,486
2,440
1848
3,463
2,436
1849
3,196
2,301
The returns for 1850 are not yet completed.—R. H.]
Composition tube, being an amalgam of certain metals,calculated to resist the action of acids contained in wateror gas. _
496 The Duke of Devonshire, and his Agent, Capt.
Eddy, Grassington —Producers.
Specimen of the Devonshire lode at Grassingtonmines.
Specimen of the gritstone, in which the lead occurs.
.Vein specimens from other lodes.
Transverse section of the Devonshire lode.
[The lode in the Grassington mines offers an exceptionto the common rule of lead veins in England, the wholeproduce being obtained in gritty beds alternating withthe limestone and shale, and not in the limestone, as itusually occurs. The veins worked in this district aregenerally with faults, and the veinstone is chiefly calcspar, fluor spar, and barytes.—D. T. A.]
497 Pattinson & Cain, Newcastle-upon-Tyne —
Producers.
Specimens of a peculiar ore of lead, viz., arsenio-phos-phate of lead, rarely found in such large masses. FromDry Gill Mine, near Hesket New Market, Cumberland.
[This appears to be the mineral called by Breithaupt,Kampylite, an arseniate of lead, in which the arsenic ispartially replaced by phosphorus.
The arsenio-phosphate of lead from this mine has beenemployed in glass manufacture, for the purpose of givinghigh transparency to the best flint or crystal, whichappeared to be produced by the formation of a lead glass,which may be regarded as a phosphate of lead and silica.—R. H.] _
498 Bennett, Thomas, 11 Woodbridge Street,
Clerkenwell —Manufacturer.
Specimen of uniform leaf gold, manufactured by steammachinery, for gilding large plain surfaces, and for ex-terior decorations; of an extra deep colour, for gildinglooking-glasses, cornices, &c.
499 Smith, R., Blackford, Perthshire —Inventor.
Minerals from the Ochills, collected by the exhibitor.
Two new alkaloids, <( cytisuine,” found in the bark of thelaburnum in combination with meconic acid; and euphor-bine, from Euphorbia officinalis. Starch, from the tubersof the Lunaria biennis; and iodine, from the Polytrichumundulatum.
500 Phillips, Smith, & Co., Llanelly, Wales —
Manufacturers.
Series of specimens illustrative of the manufacture oftin plates.
[To prepare tin plates, sheets of iron are carefullycleaned from all oxidation and from every trace of or-ganic matter: then being dipped into a saline solution,which serves as a flux, they are dipped into melted tin,which is diffused by heat over the surface, and the tinplates completed.]
Pig-iron, as received from the blast furnace.
Rough bar made from pig-iron, first melted and refinedby blast and coke fuel, and converted into malleable;iron in a clnircoal fire, stamped and rolled into a rough bar.
Bar-iron made from the rough bar heated with blastand coke in a hollow fire, hammered and rolled into afinished bar.
Sheet-iron, known as black plate, rolled in case-hardened rolls from the bar-iron.
Black plate cleaned in a preparation of sulphuric acidpassed through planished rolls, and softened by heatingin pots previous to being coated with tin.
Sheet of black plate, partly tinned.
Wooden boxes, each containing a specimen of finishedsheets of different sizes and thickness.
502 Jenkins, William Harry, Truro —Producer.
Specimens of arsenic:—White arsenic, arsenious acid,
used in glass manufactories, in patent shot manufactories,for washes for sheep, to preserve the wool and prevent thefly, and for preventing smut in wheat, &c.; white arsenic,in crystals, and sublimated, for the same purposes.Realgar, sulpliuret of arsenic, used by painters as orangered pigment ; orpiment, used by painters as yellowpigment.
Varieties of rarer minerals from various parts ofCornwall .
Specimens of wolfram from various tin mines in Corn-wall , used as a mordant in dying calicoes.
Varieties of mundics, or pyrites, from various mines inCornwall—Mangan Mine, an arsenuriet of iron. WhealWithey, near Truro; Baldher Mine, near Truro ; RoyalPolberrow Consols Mine in St. Agnes; Wheel Andrew andNangiles, near Truro , and others, a sulphuret of iron.Assorted specimens of pyrites of various qualities, fromdifferent mines, by the use of which, in combinations,a large produce of sulphuric acid is obtained.
[The arsenical pyrites, and the copper and iron orescontaining arsenic, are the common sources for this sub-stance. The ores are first roasted in “burning houses,”and the volatile matters, sulphur and arsenic, collectedin the flues. These are afterwards separated from eachother by a more delicate process, so as to sublime oneand not the other.
Wolfram , tungstate of iron, has only lately been in-troduced into the market. The tungstate of soda andtungstic acid are proposed to be employed as a mordant,and a new crimson pigment is an oxide of tungsten.—R. H.] _
503 Davey, Stephen, Redruth —Miner.
Specimens of ores of zinc.
504 Cole, Edward Joseph— Producer.
Rich specimen of tin ore, estimated to contain 60 percent, black tin, raised January, 1851, from Risehill mine,near Tavistock.
504a Nicholson, Sir Arthur, Fetlar, Zetland —Producer.
Specimens of clays, chromate of iron, black lead, andmagnetic sand from Fetlar, Shetland Islands .
[The chromate of iron is chiefly used in the productionof chromate of potash, the ore being cleaned, pounded,calcined with a certain proportion of nitre, and evaporatedafter lixiviation with water. From the neutral chromatethus obtained, or the bichromate, are produced chromateof lead (chrome yellow); a green oxide used as an enamelcolour in porcelain (chrome green); and a beautiful ver-milion (subchromate of lead). Chromic acid is alsomanufactured from the same mineral. Chromate ofiron is obtained in England principally from the ShetlandIslands.—D. T. A.]