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TIN MANUFACTURE AND TRADE. 



TIN, MEDICAL PROPERTIES OF. 



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ingredient in many useful alloys, for which iU ready fusibility, iU 

 cleanliness, and ita beautiful appearance, render it especially valuable, 

 or a* the basis of chemical compounds used in dyeing, kc. It is rarely 

 employed alone in our metalline manufactures owing to its softness, 

 but when laid in a thin coat upon the surface of sheet-iron by Uie 

 .process of TINMXO, it produces a material of extensive use in the 

 manufacture of culinary and other articles. In this country the greater 

 portion of the tin used in the manufacture of articles composed ex- 

 clusively of that metal is that which in expanded by rolling or 

 hammering, or by a combination of the two operations, into leaves 

 or sheets barely one-thousandth part of an inch in thickness, under 

 the name of tin -foil. [Foil..] 



The art of tin-plate working, or of forming sheet* of tinned iron into 

 vessels and utensils, depends more on the manual dexterity of the 

 workman than upon any peculiarity in the tools he requires, which 

 are few and simple, consisting of bench and hand-shears, mallet* 

 and hammers, steel heads and wooden blocks, soldering-irons, and 

 snagea. In the formation of a vessel the first operation is to cut the 

 plates to the proper size and form with shears ; and when the dimen- 

 sions of the article require it, to join them together, which is done 

 either by simply laying the edge of one plate over that of the other, or 

 by folding the edges together with laps, and then soldering them. 

 Similar joints ore required when gores or other pieces ore to be in- 

 serted, and also at the junction by which a cylinder is closed in. The 

 usual method of forming lap, bends, or folds for this or other purposes 

 is to lay the plate over the edge of the bench, and to bend it by 

 repeated strokes with a hammer. After a tin vessel has been rounded 

 upon a block or mandril, by striking it with a wooden mallet, and the 

 seams finished as above described, all its exterior edges are strengthened 

 by bending a thick iron wire into the proper form, applying it to what 

 would otherwise be the raw edges of the metal, and dexterously folding 

 them over it with a hammer. By this means the appearance of the 

 articles is improved, and their durability and strength are greatly 

 increased. A superior kind of tin-ware, commonly known as blm-k-tin, 

 is carefully finished by beating or planishing with a polished steel 

 hammer upon a metal stake; by which means the surface, which 

 otherwise appears somewhat wavy, is made very smooth and silvery, 

 especially after it has been polished with dry whiting. It ia principally 

 in the production of block-tin wares that twagimj ia resorted to as a 

 ready means of producing grooved or ridged borders or other embossed 

 ornaments. This process consists in striking the metal between two 

 steel dies or swages, the faces of which bear the desired pattern, and 

 are made counterparts to each other. The mouldings round the edges 

 of dish-covers and other similar articles are produced in thia way ; the 

 swages embossing the pattern in short lengths, and the article being 

 gradually turned round until every part of its circumference baa been 

 submitted to their action. The lower die is usually fixed in an appa- 

 ratus to which moveable guides are attached to insure the correct 

 position of the article to be operated on, and the upper is made in the 

 form of a hammer, the handle of which is pivoted so as to insure its 

 descent in precisely the right position. Sometimes the requisite power 

 is applied by simply working the upper swage or swage-hammer itself ; 

 but in other CIJSM the head of the swage-hammer is struck with a 

 mallet. Very many ornamental articles are produced by embossing or 

 tamping tin-plate, in the same manner as other metallic sheets, with a 

 fly-press or other machinery. Cheap coffin-plates are manufactured a< 

 Birmingham in this way ; and these and imiUr articles are sometimes 

 lacquered, painted, or japanned. A very beautiful method of orna- 

 menting tin wares by producing a crystallised appearance on the surface 

 was much practised a few yean since, under the name of moire mttal- 

 liqut. It is described under MUIK& 



Tin forms the principal ingredient in various kinds of pewter am' 

 other white metallic alloys, which are manufactured into domestic 

 utensils by casting, stamping, and other processes in which much in 

 genuity is displayed. The Britannia metal manufacture was commence* 

 on a large scale at Sheffield, where it is still carried on, about the year 

 1770 ; and the brilliancy, lightness, and cheapness of the wares, which 

 when well made, greatly resemble silver, have secured for them a very 

 extensive sale in this and other countries. The tin is first melted ant 

 railed to a red beat in a cast-iron pot, and then antimony, copper, anc 

 brass are successively poured into it from the crucibles in which they 

 have been melted ; the mass being stirred during the operation, to 

 complete the mixture. The fusion being completed by the continue! 

 application of fire under the pot, the metal is removed by ladles to 

 cast-iron boxes or moulds, in which it is cast into slabs fifteen inches 

 long, six inches wide, and one inch thick; or if for casting suial 

 articles, into smaller moulds to form it into convenient ingots. Th< 

 thick slab* of metal are then extended by passing them between 

 polished steel rollers until they are reduced to the required degree o 

 tenuity. The principal consumption in for candlesticks, tea-pots, coffee 

 biggins, and other vessels for containing liquids. The feet of candle 

 sticks, the bodies of tea-pots, and other articles having embosset 

 work, are stamped between dies; and when the shape of the article 

 will not allow it to be stamped in one piece, it is stamped in halves 

 which are subsequently fitted and soldered together. Articled ap 

 preaching the globular form may in like manner be stamped in three 

 or more piece*. Plaster casU are produced of the required jnttvrn 

 either from original models or designs, or from manufactured srticl< 



f silver ; and from these are made moulds or dies of fine hard pig-iron, 

 which, with a very little finishing, form dies fit for stamping so tract- 

 able a metal. When very thin, it may even be stamped m dies of 

 >rass or of spoon-metal The great facility with which this alloy may 

 moulded to any required form is illustrated by the operation termed 

 innniuy, by which the bodies of tea-pots with concentric circular swell* 

 are usually formed. [Snssrso.] Many small vessels, spoons, and 

 ither articles are cast m on alloy somewhat harder than that which is 

 rolled into sheet*. The facility with which Britannia metal may be 

 run into any shape and cut in the lathe, as for turning measures and 

 small vessels previously formed by casting, is a great recommendation 

 to the manufacturer. Articles of this metal are cleaned from t! 

 resin, and other impurities acquired during their formation, by boiling 

 n water containing soap ; after which they are polished, cither by 

 land, or more commonly by the buff and brush set in motion by a 

 steam-engine. After buffing and brushing, the articles are boiled in a 

 solution of pearlash, and finally hand-brushed and hand-polished by an 

 application of soft soap, a little oil, and powdered rotten-stone. This 

 operation is usually performed by females; as it is fnmul that m> in- 

 strument can supply an effectual substitute for a soft bond, which is 

 one of the first requisites inquired for when persons apply for work 

 in this department. 



Produce and Trade. The history of the trade in tin commences 

 with the very earliest records of commercial intercourse with the 

 British islands. Wo shall only notice it, however, as it has existed within 

 the last two centuries. Davenant gives some interesting inf<>n 

 concerning it soon after the middle of the 17th century. In 1663 our 

 exports of tin to all foreign countries amounted to 153 tons; in 1669 

 to 240 tons; in the three years of peace, from 1698 to 1700, on an 

 average to 1297 tons ; and in the ten years of war, from 1700 to 1710, 

 on an average to 1094 tons. In these last ten years the annual pur- 

 chases of the Dutch amounted to 300 tons, of the estimated value 

 of 21,3747. But the produce of the mines more than kept pace with 

 the increased demand ; and when Davenant wrote. Queen Anne had 

 between 4000 and 5000 tons of tin on hand, a quantity equal to four 

 or five years' consumption. The produce of the mines went on increas- 

 ing, and the accumulation to which. Davenant alludes is only half a 

 year's produce of the mines at present. From 1750 to 1785 the produce 

 of the mines varied from 2273 tons to 3005 tons ; the average price 

 being 64. 6</. per cwt. From 1789 to 1816 the annual average quantity 

 was 2875 tons at 79. 9rf. per cwt From 1817 to 1837 inclusive, the 

 annual average was 4211 tons, and the average price paid to the tinner 

 was 73s. the cwt. In 1787 Banca tin was imported into this country 

 for the first time, and the price of Cornish tin soon fell to 68*. the cwt., 

 and would have declined still further if a new market had not been 

 opened. The purser of an Indiaman, who took some tin from the 

 Molucca islands to China in 1787, found the speculation so profitable 

 that the East India Company were induced to direct their attention 

 to the trade, and the Company entered into arrangements with the 

 Cornish tinners for an annual supply. The purchases of the company 

 were mode at low prices, but the tinners were indemnified by (! 

 artificial scarcity which raised prices in the home market. At first the 

 Company paid only 68f. 13. 4d. the ton, delivered on board in London ; 

 this gradually rose to SOI. The connection finally ceased in 1817, as 

 the supply of the homo market had become more profitable. 



On account of the increasing consumption at home, the portion 

 exported gradually lessened from 7-lOths to l-5th of the whole. Most 

 of the foreign tin imported is for re-exportation ; for it can be sup|>li> <1 

 to the continent cheaper than English tin. A duty was formerly ]iil 

 upon all tin raised in Cornwall, to the duchy ; but as the mode of 

 stamping the blocks, for the estimation of duty, was very inconvenient, 

 the duty was commuted in 1838 for a perpetual annuity ; the duty 

 amounted to about 5*. per 120 Ibs. Under the tariff of 1842, foreign 

 tin-ore was rendered admissible on payment of a customs' duty of 5u. 

 per ton. At present the duty is very light free if unmanufactured, 

 and 10. per cent, if manufactured. The produce of the British tin 

 mines from 1848 to 1855 varied from 6000 to 7000 tons a year. In 

 1857 it reached the large amount of 10,000 tons. So varying is the 

 quality, that the price in the last-named year ranged from I 

 the total value was 750,000/., giving an average of about 751. per ton. 

 This was the value of the ore itself. The metallic tin, after smelting 

 and refining, ranged from 108/. to 146/. per ton. The English mines 

 which were most productive in that year were the Great Huel Vor, 

 Dolcoath, Cam Brea, Par Consols, and Providence ; the produce ranged 

 from 54,0001. down to 23,0002., from these five mines. 



In the last financial year (I860), there was imported 58,000 cwts. of 

 tin, in blocks, ingots, bars, and slabs ; and the exports in the same 

 year amounted to 66,000 cwts. of unwrought tin, besides 1 ,500,0002. in 

 value of tin-plates, in which the greater part of the weight is of iron. 



TIN, MEDICAL I'Knl'KK Tl KS OK. It cannot be asserted that 

 tin in n metallic state has no influence over the human system, as 

 many respectable writers affirm that tin-filings are decidedly anthel- 

 mintic, and that this is not owing to mechanical irritation of the 

 worms causing them to be detached from the surface of the intes- 

 tines ; it is stated that water in which tin has been boiled, and wim> 

 digested in a tin vessel, are also anthelmintic. Others, denying to tin 

 any inherent power over worm*, have attributed these effects to the 

 presence of a small portion of arsenic. Be this as it may, it is a very 



