TIN. 



boiling the protoxyd in dilute iiiciic aciJ, drying by eva- 

 poraliun, and licitiiig to rcdntfu. 



Till forms likewife two combinations with chlorine. When 

 tin is burnt in chlorine, a very volatile clear liquor is formed, 

 a non^condudor of eledricity, and which, when mixed with 

 a little water, becomes a folid cryilalline fubftance, a true 

 muriate of tin, containing the peroxyd of tin. This com- 

 pound has been called the fmoLing liquor of Liiavlus, from 

 its difcoverer, who formed it by diftilling together amalgam 

 of tin and corrofive fublimate. According to the experi- 

 ments of Dr. John Davy, it confifts of two atoms or pro- 

 portions of chlorine united to one of tin ; or of about 



Tin 



Chlorine 



lOO. 



121.82 



ProMonde of tin, firR defcribed by Dr. J. Davy, is a 

 grey, femi-tranlparent, cryftaUine folid, and may be formed 

 by heating together amalgam of tin and calomel. Accord- 

 ing to the fame chemift, it confifts of one atom or propor- 

 tion of chlorine united to one of tin ; or of about 



Tin 

 Chlorine 



100. 

 60.72 



Tin combines readily with fulphur and phofphorus, but 

 not with hydrogen, azote, carbon, or boron. 



There are two fulphurets of tin ; the firft may be formed 

 by fufing tin and fulphur together : it is of a blueifh colour, 

 and lamellated ftrudure ; and from the experiments of Dr. 

 J. Davy, confifts of one proportion of tin united to one of 

 fulphur. The other fulphuret of tin is made by heating to- 

 gether the peroxyd of tin and fulphur. It is of a beautiful 

 gold colour, and appears in fine flakes. It was formerly 

 called aurum mufivum, and various complicated procefles 

 given for forming it. Pelletier and Prouft inveftigated its 

 nature, and concluded it to be a compound of oxyd of tin 

 and fulphur ; but Dr. Davy has ftiewn that this is not the 

 eafc, and that it confifts merely of one proportion of me- 

 tallic tin united to one proportion of fulphur. 



The phofphurct of tin may be formed by heating the two 

 fubftances together. Only one phofphuret is known : it 

 has a metalUc appearance, and is 10 foft that it may be cut 

 with a knife. When gently heated in the air, the phofpho- 

 rus takes fire. According to the experiments of fir H. 

 Davy, it contains about 17 per cent, of phofphorus, and 

 confifts therefore of one atom or proportion of phofphorus 

 united to one of tin. 



Tin combines with moft of the metals, and fome of its 

 alloys are much employed. 



Its alloys with the metals of the fixed alkalies fpeedily 

 tarnifh in the air, and cffervefce in water. 



It readily unites with gold by fufion, and was formerly 

 fuppofed to have the property of rendering this metal brit- 

 tle ; but this has been more recently denied. An alloy of 

 1 1 gold and i of tin, was found by Mr. Hatchett to have a 

 pale whilifti colour, brittle when thick, but when cut thin, 

 capable of being bent eafily. Its fraAure was fine-grained, 

 and of an earthy appearance. Mr. Alchorne found, that 

 gold alloyed with no more than ^yth of tin, retains its 

 duflility fufficiently to be rolled and ftamped in the ufual 

 manner. But Mr. Tillet Ihewed, that when heated to red- 

 nefs, the tin melts, and the alloy falls to pieces. 



Its alloys with platina, according to Dr. Lewis, are brit- 

 tle and dark-coloured, when the two metals are in equal pro- 

 portions. The alloys of tin and filver are very hard and 

 jjrittle. The alloys, or rather amalgams, of tin ar.d mer- 



8 



cury differ in hardnefg, according to the proponlons in 

 which tlie two metals are mixed ; three p^uLs oi mercury aiiu 

 one of tin form an amalgam which cryltallizes in cubes, or, 

 according to Sage, in the form of brilliant fquare plates, 

 thin towards the edges. Tin readily combines with copper, 

 aud forms alloys exceedingly ufeful for a variety of pur 

 pofes, as will be briefly noticed when we fpeak of the ufus 

 of this metal. Tin does not readily combine with iron, 

 but their union may be effiefted by fufing them together in 

 clofe veifels : it combines with zinc by fufion, and the alloy 

 is harder than zinc, and ftronger than tin : with lead it rea- 

 dily unites in all proportions, and the lead by the addition 

 becomes confiderably harder. 



The oxyds of tin are capable of combining with the alka- 

 lies, and of forming vi\i\\ them peculiar compounds. 



Salts of Tin Tin is oxydated and diflblved by many oi 



the acids, and forms falts, differing in their nature ac- 

 cording to the degree of oxydizement of the metal. 



Nitrates of Tin. — Concentrated nitric acid (fpecific gra- 

 vity 1.48) poured on tin, exerts but little aftion upon it ; 

 but if a little water be added, a violent adlion is exerted, 

 and peroxyd of tin is formed, which feparates in the form of a 

 white powder, this oxyd being apparently incapable of 

 combining with nitric acid : in this cafe, both the acid and 

 the water are decompofcd, and nitrate of ammonia is formed ; 

 but if the acid be diluted, and care be taken to moderate its 

 aftion upon the metal, the water only is chiefly decompofed, 

 and the protoxyd of tin is formed, which combining 

 with the nitric acid, forms a folution of a yellow colour, 

 which is a real nitrate of tin. Still, however, a little ni- 

 trate of ammonia is formed, and the nitrate of tin itfelf i» 

 not permanent, the metal continuing to pafs to the ftate of 

 peroxyd, and gradually feparating. The fame change is 

 produced by heating the folution, a precipitate being depo- 

 fited, which, however, is partly fubnitrate of tin. 



Muriates of Tin. — We have already fpoken of the clJo- 

 rides, or compounds of tin with chlorine. Now if water' 

 be added to thefe chlorides, they are converted into muriates 

 of tin. The muriate of tin, in which the metal is in the 

 ftate of protoxyd, may be formed, however, by diffolving 

 tin in about four times its weight of muriatic acid : hydro- 

 gen efcapes, and the folution has a brownifh-yellow colour, 

 and yields, on evaporation, fmall needle -(baped cryftals, fo- 

 luble in water, and foraewhat deliquefcent. Water poured 

 upon it in fmall quantity decompofes it, and converts it into 

 a fubmuriate, which is precipitated, and a fuper-muriate, 

 which remains in folution. A fimilar effeft is produced by 

 the alkalies, when not added in excefs. This muriate of 

 tin, formed of the protoxyd, has a great tendency to com- 

 bine with oxygen, and to pafs into the ftate of muriates 

 with the peroxyd, and this property enables it to exert 

 many curious efforts upon other metallic falts. Thus, for 

 example, the red oxyd of raircury, the black oxyd of man- 

 ganefe, the white oxyd of antimony, the oxyds of zinc and 

 filver, are deprived of their oxygen by this fait, and reduced 

 to the metallic ftate. The muriate of tin with the peroxyd 

 of the metal may be formed as before mentioned. It is ca- 

 pable of cryftallizing, and poffeffes properties quite different 

 from thofe of the muriate above defcribed. It is much 

 ufed by dyers, who generally form it by diffolving tin in 

 nitro-muriatic acid. 



Sulphate of Tin. — Sulphuric acid, when cold, has little 

 aftion on tin, but affifted by a moderate heat, it attrafts 

 oxygen from it ; fulphurous acid gas is evolved, and a ful- 

 phate of tin is formed, which yields, when evaporated, 

 fmall needle -formed cryftals. It is probable there are two, 



fulphatcs 



