C H E M I S T R Y. 



tin when assisted by heat, and tlic salt farmed is 

 muriate of tin. My evaporation it is obtained in 

 needle-shaped crystals soluble in water, and some- 

 what deliquescent. It has a strong affinity for oxy- 

 gen, and readily imbibes it from the atmosphere, from 

 oxy -muriatic and nitric acids, and from various me- 

 tallic oxide* and salts. Hence the remarkable changes 

 which it produces on many metallic solutions. 



Sp. 3. Sul/thnle <if Tin. When tin is kept in fiil- 

 phuric acid, little action takes place. 1 !<>\vi vcr, the 

 tin is gradually oxidized, and sulphurous acid gas is 

 emitted. The sulphate of tin, formed, may be ob- 

 tained in the slate of fine needles by evaporation. It 

 may be readily obtained by pouring sulphuric acid 

 into muriate of tin ; a white powder precipitates, 

 which is the sulphate, and winch dissolves ID water 

 and crystal 



The Oiysulphate of tin does not crystalli/.e, but 

 assumes the form of a jelly. 



Sp. 4. Sii/p/iile of 1'in. When tin H kept in sul- 

 phurous acid, the acid is decomposed, oxide of tin 

 dissolved, and sulphuret of tin precipitated. 



Sp. 5. Phosphate of Tin. A white powder inso- 

 luble in water. 



Sp. 6. Carbonate of Tin. As far as is known, 

 this species of salt does not exist. 



Sp. 7. Fluate of Tin. A gelatinous solution ha- 

 ing a very disagreeable taste. 



Sp. 8. Jioratc of Tin. A white powder insoluble 

 in water. 



Sp. 9. Acctat-d Tin. The acetate of tin crystal- 

 lizes ; the oxacetate forms a gummy incrystallizable 

 mass. 



Sp. 10. Succinate of Tin. This salt crystallizes, 

 and is soluble in wattr. 



Sp. 11. Benziate of Tin. This salt is soluble in 

 water, but in.-oluble in alcohol. 



Sp. 12. Qxalule of Tin. 1'nsmatic crystals, soluble 

 in water. 



Sp. 13. Arteniate of Tin. A white insoluble 

 powder.. 



GBNUS XII. Salts of Lead. 



Salt* of Many of these salts are scarcely soluble in water. 



lead. Those that are, form colourless solutions, which have 



usually a sweet taste. The prus&iates occasion a white 

 precipitate in these solutions ; hydrosulphuret of pot- 

 ash, a black precipitate ; infusion of nutgalls, a white 

 precipitate. 



Sp. 1. Nitrated Lead. Of this salt there are two 

 varieties ; the first, composedof yellowoxide and nitric 

 acid, has been long known ; we shall call it oryi- 

 irale ; the second, or nilrale f has been lately disco- 

 vered by Proust. 



1. Ofi/nitrale. This salt is easily obtained by dis- 

 solving lead in diluted nitric acid, and evaporating the 

 solution. The crystal are sometimes tetrahedrons, 

 having their apexes truncated ; sometimes octahe- 

 drons. They are opake and white, and have a silvery 

 lustre. Their taste ib sweet and l.ar-,h. They are 

 not altered by exposure to the air. They dissolve in 

 less than eight parts of boiling water. \Vhen heated, 

 it decrepitates, and in a strong heat the acid is driven 

 off, while at the same time the oxide is partially re- 



duced to the metallic state. This salt is composed Element* 

 6 yellow oxide, SJ- acid and water. 



'2. Silrotc. Tins salt is obtained by boilin 

 in a solution of ofi/nitrate. A portion ot 

 dissolved, and the solution acquires a yellow colour. 

 When evaporated, the salt crystallizes in scales, and 

 in small prisms. The oxide i,i Dr Thomson's trials 

 appeared to be the yellow ; but liueholz affirms that it 

 contains l.-v oxygen. This salt is composed of SJ.5 

 oxide, IS.'iacid. 



Sp. 2. Hyffrosymttripte <>f Lead. This salt is 

 obtained by passing a current ot oxymuriatic acid 

 through water, in which oxide of lead is suspend- 

 ed. It is more soluble than muriate of lead, and is 

 easily decomposed. 



Sp. 3. Sulphate of Lead. This salt may be ob- 

 tained by pour.'ig sulphuric acid, or an alkaline 

 sulphate, into nitrate of lead. It is a white powder, 

 insoluble in water, in alcohol, and in nitric and acetic 

 acids. It is found native, crystallized in octahedron?. 

 It is composed ot about '25 acid and 75 yellow oxide. 

 A hundred parts of it, according to Kirwan, con- 

 tain 71 of metallic lead. It may be heated to red- 

 ness in a platinum crucible without alteration, but 

 when in contact with charcoal, it melts, and the lead 

 is reduced. 



Sp. 4-. Sulpf/ilc nf Lead. This is a tastcl.-ss whire 

 powder, insoluble in water. It is composed of about 

 74.5 oxide, and i>~>.5 acid. 



Sp. 5. Phosphate of Lead. A white tasteless 

 powder insoluble in water, easily obtained by pouring 

 phosphate of soda into niirate of lead. It is found 

 native, usuolly of a green or yellow colour, and is 

 often crystallized in six-sided prisjns. It is soldi-K- 

 in nitric and muriatic acids, and from the last solution 

 muriate of lead precipitate?. When heated, it melts, 

 and assumes, on cooling, a regular polyhedral form. 

 It is composed of IS acid and 82 yellowish oxid.*. 



Sp. 6. Carbonate of Lead. This ii a white pow- 

 der insoluble in water, easily obtained by mixing so- 

 lutions of nitrate of lead, and an alkaline carbonate. 

 It is found native, crystallized in six sided prisms, 

 and in tables. It is employed as a paint, under the 

 name of tr/iiie It'tul. It is composed of 16j acid, and 

 83y yellow ox de. 



Sp. 7- Finale of Lend. A white powd.-r insoluble 

 in water, unless there be an excess of acid. 



Sp. 8. Jitirnlc of Lead. A white insoluble powder. 

 Before the blowpipe it melts into a colourless glass. 

 Sp. 9. Acetate of Lead. Of this salt there are two 

 varieties, the superiicftate and acetate. 



1. $upenuxtatei Thir s.ilt has been long known. 

 It is usually distinguished by "the name ot .\nsar of 

 lend. It may be obtained by dissolving acetate of 

 lead in arctic acid. Jt i much used by dyers and 

 calico-printers. Its crystals are small needles, \v:th a 

 glossy appearance 1-ke s .tin. It has a sweet ami ra- 

 ther astringent taste. Water dissolves rather more 

 than jth ot its weight of this salt. It is m.t .iliercd 

 by exposure to the air. When distilled, there comes 

 over water arid.ilated wth acetic acid, then a yellowr 

 inflammable liquor, which lias some of the properties 

 of ether. Tl.e ya-s rxtricat d arc carbonic acid in 

 considerable quantity, with a wry little 1 e.ivy i. fhm- 

 mable air. This salt is composed of 26 acid, 58 yel- 

 low oxide, 16 water. 



