TIN. 



fulpliates of tin, tliougli llicir properties do not appear hi- 

 therto to liave been diilindtly defined. 



The phofphale, JJiiate, and borate of tin may be formed 

 by double decompofition, by adding folutions of their alka- 

 line falls to a folution of muriate of tin. They are all info- 

 luble compounds, and have been but impcrfeftly examined. 

 No carbonate of tin appears to exift. 



The other falts of tin are unimportant, and but little 

 known. The acetate has been moft invelligated : it may be 

 formed by boiling tin in acetic acid. The folution has a 

 whitifli colour, and yields cryftals by evaporation. There 

 appears, however, to be another acetate, ( formed probably 

 with the peroxyd of the metal,) that does not cryftallize, 

 but is capable of £xiiling only, on evaporation, in tiic form 

 of a gummy mafs. 



Ufcs of Tin and its CoinpomuU Tin and its compounds 



are extenfively ufcd in the arts. We (hall here briefly point 

 out fome of the more important operations in which they 

 are concerned, referring our readers for further particulars 

 to the different articles themfelves. An amalgam of tin and 

 mercury forms the metallic coat of glafs mirrors. For the 

 method of performing this operation, fee the article Silver- 

 ing o/" Mirrors. 



The compounds of tin with copper are very important. 

 Of this alloy cannons are made, alfo bcU-metal, bronze, and the 

 mirrors ox fpecula of telefcopes. For thefe different purpofes, 

 the two metals are mixed in different proportions, which are 

 pointed out more particularly under their refpeftive articles. 



Veffels of copper, efpecially for culinary purpofes, are 

 iifually covered with a thin coating of tin, to prevent 

 the copper from oxydating. (See the article Tinning.) 

 Thin iron plates covered with this metal, form what is 

 known by the name of tin-plate ; which fee. 



The oxyd of tin, mixed with that of lead, forms putty, 

 which is much ufed in pohfhing metals. See Puttv and 

 Speculum. 



Tin alloyed with lead iortm folder ; which fee. 



Of the falts of tin, a folution of the muriate, or dyers' 

 liquor, as it is termed, is ufed as a mordant in dyeing fcarlet. 

 ee the articles Dyeing, Mordant, and Red. 



The folution of tin in aqua regia, added to the tinftures 

 of cochineal, of gum-lac, and of fome other red tinftures, 

 heightens the colour of thefe, and changes it from a crim- 

 fon or purple to a vivid reddifli- yellow, or fire-coloured 

 fcarlet. The new fcarlet, or Bow dye, is obtained in this man- 

 ner ; and it is faid, that our moft beautiful and lafting- 

 coloured fine cloths owe their fuperlative excellence to the 

 retentivenefs given by our fine grain-tin ; infomuch, that 

 the Englifli fuperfine broad-cloths, dyed in grain by the help 

 of this ingredient, are become famous in all markets of the 

 ■known world. 



Mr. Pryce apprehends, that the purple dye of the Ty- 

 rians owed its reputation wholly, or in part, to the ufe of 

 our tin in the compofition of their dye-ftulF, as the tin-trade 

 was folely under their own direftion. 



This colour, however, fucceeds only with wool and other 

 animal matters. Attempts have been made, but without 

 fuccefs, to give this colour to thread, to cotton, and even 

 lo filk, though this latter fubftance has many properties of 

 animal matters. The folution of tin made with marine acid 

 alone, or with vitriolic acid, does only give to red lindtures 

 a erimfon colour, as alum does. Vegetable acids, as vine- 

 gar and cream of tartar, are alfo capable of diflblving tin. 



Tin or its compounds are not ufed in medicine. They do 



not appear to be of a poifonous nature ; but the muriate of 



tin, taken into the flomach in confrderable quantity, fpeedily 



induces death, apparently merely from its conofivc qualities. 



Vol. XXXV. 



It was formerly rpcommeiidcd for its anthelmintic virtues • 

 but it is polTible, fays Dr. Lewis, that thefe may proceed 

 not fo much from the pure metal, as from a certain fub- 

 flance of a different or arfenical nature, of which the piucll 

 forts of tin arc found to ])articipate. 



The principal preparations of tin are as follow : 



Tin, Butter of, is a name given by fome chemifts to a 

 combination of tin with the concentrated marine acid of cor- 

 rofive fublimatc. It is procured by reducing thefe fub- 

 flances into fmall parts, and mixing them together : this 

 mixture will, by degrees, be moiftened by attrafting the hu- 

 midity of the air. The decompofition of the corrofive fub- 

 limate by the tin is more fpeedily efTefted by diftillation. 



Tin, Calx of, is the metal reduced into powder, either 

 by means of fire, or by being dilfolved in an acid menflruum, 

 and precipitated with an alkali. 



Tin, Cerufs of. See Spani/]} White. 



Tin, Diaphoretic of. See Antiiiecticum Poterii. 



Tin, Flowers of, are a kind of white cofmetic, or paint 

 for the complexion, drawn from tin with fal ammoniac, by 

 means of fublimation. 



Tin, Gold-coloured preparation of is made by adding fix 

 ounces of mercury to twelve of melted tin, pulverizing the 

 cold mals, mixing with it ieven ounces of llowers of fulph\ir 

 and fix of fal ammoniac, and fubUming in a matrafs. 



This preparation is called aurum mofnicuin, and as a medi- 

 cine is httle regarded, though forn\crly much elleemed 

 againft hyllerical and hypochondriacal complaints, malignant 

 fevers, and venereal diforders. Upon experiment, it appears 

 to be little more than calx of tin. 



Tin, Salt of, Sal Jovi', is prepared from twelve ounces of 

 calx of tin, and four of aqua regia, diluted with twenty-four 

 of water : after digeftion for two days, the veffel is to be 

 fhaken, the more ponderous part of the calx fuffcred to fet- 

 tle, the turbid liquor poured off, and evaporated almoft to 

 drynefs, and the mafs farther exficcated on brown paper : 

 to the remaining calx half tlie quantity of frefli menftruum 

 is to be added, and the procefs repeated. Dr. Lewis's ex- 

 perience has not enabled him to pronounce on the virtues of 

 this fait, which is in taflc very Iharp and corrofive : he thinks 

 it needlefs to calcine the metal, as tin uncalcined diffolvcs 

 much more eafily and plentifully, and the folution is in both 

 cafes the fame. According to Hoffmann, the folution of tin 

 is a (trong purgative. Lewis's Mat. Med. 



Tin is alfo a word ufed by fome of the chemical writers 

 to exprefs fulphur. 



TlVi-Copin^, in Rural Economy, a fort of covering of tliis 

 kind of metallic fubllance in the fheet form, which is not un- 

 frequently employed on the upper parts of the frames, 

 flands, or ftaddles of corn-flacks, for the purpofe of pre- 

 venting deftruftive vermin from entering or getting into 

 them. It is a chcip, ready, convenient, and ufeful mate- 

 rial in this intention, in many cafes, which the arable fanner 

 fhould not be inattentive to in his flack-yard. 



Tis-Flriors, a contrivance ufed by our hulbandmen who 

 propagate hops, to dry them after the gathering. See 



OOST. 



It is thus done : Let a fquare brick room be built, with 

 a door on one fide, and a long fire-place of a foot wide in the 

 middle, reaching almoft acrofs it ; let holes be made at the 

 fides of this fire-place, to let out the heat into the room ; 

 and at the height of five feet above this, let a floor be made 

 of laths of an inch thick, laid lattice-wife. Let this be 

 covered with great plates of double tin, taking care that the 

 joinings of the tin be well foldered, and lie upon the laths, 

 nor over the interftices, which may be about four inches 

 wide. Let a row of boards be fitted round the edge of 



4 U this 



