Tltf-MORDANTS 1009 



Tin in Ingots, blocks, bars, slabs or regulus, Imported in 1874, 184,377 cwts. ; value 

 904,488^. 



Tin unwrought Exported in 1874, 155,068 cwts. ; value 813,30$. 



For the purification of tin from tungsten, see TUNGSTEN. 



The uses of tin are very numerous. - Combined with copper, in different pro- 

 portions, it forms Bronze, and a series of other useful alloys ; for an account of which, 

 see COPPER. With iron, it forms Tin-plate ; with Lead, it constitutes Pewter, and Solder 

 of various kinds. (See LEAD.) Tin-foil coated with quicksilver makes the reflecting 

 surface of glass mirrors. (See GLASS.) Nitrate of tin affords the basis of the scarlet 

 dye* on wool, and of many bright colours to the calico-printer and the cotton-dyer. 

 (See SCAELET and TiN-MoapANTS.) A compound of tin with gold gives the fine 

 crimson and purple colours to stained glass and artificial gems. (See PURPLE 

 OF CASSIUS.) Enamel is made by fusing oxide of tin with the materials of flint 

 glass. This oxide is also an ingredient in the white and yellow glazes of pottery- 

 ware. See PUTTY POWDER. 



TMT ASSAYING. The ore of tin submitted to assay is Cassiterite, peroxide of 

 tin or black tin. When the ore is poor it must be submitted to a washing, vanning, 

 or other concentration process, to separate the peroxide of tin from vein-stuff before 

 submitting it to the assay. If the ore is associated with iron pyrites, copper pyrites, or 

 other foreign metalliferous matters, it must be calcined or treated with acids, before 

 submitting it to the final washing process. The assays are made by the dry method. 



a. Cornish method. This process is conducted in black-lead crucibles in an air-furnace 

 similar to that described in COPPER (Fig, 533). Two ounces (960 grs.) of the ore are 

 mixed with about one-fifth of its weight of culm or anthracite powder, or charcoal, 

 and heated for about twenty minutes at a high temperature ; the reduced metal is now 

 poured out into a long flat ingot-mould. The slaggy residue is then scraped out from 

 the pot, and any shots of metal separated by pounding and washing, and the total 

 weight of metal ascertained. A small quantity of borax or fluor-spar is added when 

 necessary to render the slag fluid. The assay may also be made in earthen crucibles. 



b. By Fusion with Cyanide of Potassium. This process is conducted in earthen or 

 porcelain crucibles : 100 grs. of the black tin is a convenient quantity to operate on. The 

 ore is mixed with from four to six times its weight of cyanide of potassium, and the 

 crucible and its contents exposed to a low red heat for about 20 minutes. The contents 

 are poured out into the iron mould (fig. 534, see COPPER), and when cold the button 

 of tin is detached from the slag, cleaned and weighed. 



TINCAIi. The Oriental name for crude borax. Under this name considerable 

 quantities are brought from the East Indies. But the largest quantities are obtained 

 from the lagoons near Monte Cerbole in Tuscany. Recently, tincal of a very fins 

 quality has been discovered in California. A lake in Colorado Territory contained so 

 much of the bi-borate of soda that it was found crystallised out around the edges, but 

 was soon exhausted. See BORAX. 



TINCTORIAL MATTER. The colouring-matter employed in dyeing. See 

 DYEING ; MADDER ; TURKEY RED, &c. 



TINCTURE is a title used by apothecaries to designate alcohol, in a somewhat 

 dilute state, impregnated with the active principles of either vegetable or animal 

 substances. 



TINDER ORE. (Zundererz, Ger.) An impure arsenical sulphide of antimony. 

 It is found at Andreasberg in the Hartz, in soft flexible flakes resembling tinder, of a 

 dirty reddish colour and with little lustre. 



TINE, in metallurgy, a modification of the Trompe adopted by the French. 

 TIN GLANCE is an old name of bismuth. See BISMUTH. 

 TIN-MORDANTS for dyeing scarlet. See MORDANT. 



Mordant A, as commonly made by the dyers, is composed of 3 parts of nitric acid, 

 1 part of common salt or of sal-ammoniac, and 1 of granulated tin. This preparation 

 is very uncertain. 



Mordant B. Pour into a glass globe with a long neck, 3 parts of pure nitric acid 

 at 30 B., and 1 part of muriatic acid at 17 ; shake the globe gently, avoiding the 

 corrosive vapours, and put a loose stopper in its mouth. Throw into this nitro- 

 muriatic acid, one-eighth of its weight of pure tin, in small bits at a time. When t:.o 

 solution is complete, and settled, decant it into bottles, and close them with ground 

 stoppers. It should bo diluted only when about to be used. 



Mordant c, by Dambourney. In 2 drams (Fr., 144 grs.), of pure muriatic acid, 

 dissolve 18 grains of Malacca tin. This is reckoned a good mordant for brightening 

 or fixing the colour of peachwood. 



Mordant D, by Hellot. Take 8 ounces of nitric acid, diluted with as much water ; 

 dissolve in it half an ounce of sal-ammoniac, and 2 drams of nitre. In this acid solu- 



VOL. in. 3 T 



