Chemistry. 
blocks. The ores of tin are wrought nearly in the fame 
way in Germany and in England. The purelt tin of all is 
that which comes from Malacca' and JBanca ; the firil has 
been run into moulds, which give it the form of a qua¬ 
drangular truncated pyramid,.with a narrow (lope round 
its bai ; each ingot weighs about a pound. The fecond 
is in oblong ingots, weighing forty-five or fifty pounds ; 
tlieic two kinds of tin are covered with a grey full:, more 
or lefs thick. 
The tin produced in England, which is much more 
ufed than the pure tin of the Indies, its price being lower, 
is in the form of large blocks, of about three hundred 
pounds weight. It is alloyed with copper; and, to faci¬ 
litate the fale, it is afterwards melted into (mall ingots-, 
or Hicks, of nine or ten lines in circumference, and about 
a foot and a half long. Tin is of a whiter and more 
brilliant colour than lead, but not quite fo white as (li¬ 
ver ; by the alchemills it had the name of Jupiter. It is 
eafily bent, and produces a crackling noife when bent, a 
phenomenon which we have already obferved, though 
lefs evidently, in zink, and which has been urged by 
Malouin, as an inftance of fimilarity between that metal 
and tin. This noife appears to depend on the hidden 
i'eparation of the parts of the metal, and feems to (hew, 
that a fra 61 ure takes place, though tin refills very little 
the effort which is made to bend it. “ Tin is the lighted 
of all the metals ; it is fufficiently foft to be fcratciied 
with the nail. In water it loles about one-feventh of its 
weight. It has evidently a fmell, which becomes much 
ftronger by heating or rubbing. It has likewife a pecu¬ 
liarly difagreeable fade, fo drong, that fome phyficians 
have luppofed it to have a fenfible aflion on the animal 
economy, and confequently have recommended it in fe- 
veral diforders. Its extreme foftnefs renders it fcarcely 
at all fonorous. Tin is the fecond among metals in the 
order of dublility; it is reducible beneath the hammer 
into laminae, thinner than leaves of paper, which are of 
great ufe in many arts. Its toughnefs is fuch, that a 
wire of tin, of the tenth of an inch in diameter, fupports 
a weight of forty-nine pounds and a half without break¬ 
ing. The abbe Mongez did not fucceed in his attempts 
to crydallize tin ; but De la Chenoye fucceeded, by fuf- 
.ing the tin for a number of f'ucceiiive times, by which 
means he obtained a rhomboidal affemblage of prifms or 
needles, united longitudinally to each other. 
The fpecific gravity of tin, according to Kirwan, is 
7 - 67 times that of water; according to Briffon, 7'29- It 
is not more eladic than lead. Its fufibility has not been 
well determined ; fome equivocal experiments have been 
made, which fixed it at 168 0 of Reaumur; in which caie 
its fufibility mud be greater than that of lead, which melts 
only at 258° of the fame fcale, employing the fame means. 
This fluidity cannot be determined by Wedgewood's py¬ 
rometer, becaufe that begins only at 460° of Reaumur’s 
thermometer. It melts, however, at a heat of about 420 
degrees, long before a red-heat is produced, and remains 
fixed as long as the fire is not railed; but a confiderable 
heat volatilizes it. If heated with accefs of air, its fur- 
face becomes covered with a dull greyifh pellicle, and 
aifumes a fhrivelled appearance. When this is taken 
away, the tin is feen underneath with all its metallic 
brilliancy. A new pellicle foon becomes colledled, and 
in this manner mod of the tin may be reduced into pel¬ 
licles, which are nothing elle but a metallic oxyd, or 
combination of the metal with the oxygen of the atmof- 
phere. Then take the veffel off the fire ; let it cool; pul¬ 
verize the oxyd in an iron-mortar; pals it through a 
fieve, to Separate the uncalcined portions of the tin. Take 
the oxyd thus prepared, and calcine it afrefh, in an earthen 
capfule, in a cupelling or Macquer’s furnace, for fix or 
feven hours, taking care to dir it from time to time with 
an iron hook ; the oxyd becomes white, and is more 
oxydated : in this date it is called putty of tin ; and is 
ufed-for polifhing looking-glades, deel, and other hard 
bodies. If it be expofed to an exceeding drong heat, it 
291 
melts into glafs, which (hews the prifmatic rays.' This 
oxyd may be decompofed by the addition of animal or 
vegetable combudible matters, as greafe, foap, &c. but 
not without difficulty. 
Tin heated by the biow-pipe, and thrown immediately 
on the ground, or on a done, appears fparkling. It re¬ 
fills the adlion of the air extremely well; its furface be¬ 
comes a little tarnifned-, and covered with a greyifh pow¬ 
der, which is merely fuperficial, and never penetrates into 
the metal. 
To phofphorate tin, take equal parts of tin and phof- 
phoric glafs, with one-eighth of charcoal; mix them care¬ 
fully, and melt them in a crucible; fome grains of me¬ 
tal, pretty large, will be obtained, which appear like 
tin ; but, when melted under a blow-pipe, the pliofpho- 
rus will be feen to quit the. tin, and to burn at the fur- 
face of the metal. , Care mud be taken in the manage¬ 
ment of the fire, when tin is to be melted with charcoal- 
dud and phofphoric glafs, becaufe the phofphorus readily 
quits the metal. 
Tin may be eafily combined with fulphur, by throwing 
one or two parts of fulphur in powder, on five or fix parts 
of tin melted in an iron ladle; the mixture, being agi¬ 
tated with an iron fpatula, becomes black, and takes 
fire. If it be melted in a crucible, a brittle maCs, difpofed 
in flat needles united together, is obtained. To unite 
arfenic with tin, put into a retort three parts of tin \6ith 
one-eighth part of arfenic in powder; fit on a receiver, 
and heat the retort to rednefs; very little arfenic riles, 
and a metallic lump is found at the bottom : this mix¬ 
ture contains-about one-fifteenth part of arfenic ; it cryf- 
tallizes in large facets, very brittle, and hard to melt. 
The arfeniat of potafh combines much better with tin: 
Melt equal parts of tin and arfeniat of potafh in a cru¬ 
cible ; the produft is a rough lump, brittle, and com- 
pofed of very brilliant facets. The tin, thus united to 
arfenic, will not melt under a red heat. 
Crondedt affirms, that nickel united to tin forms a 
white and brilliant mafs, which, "when calcined under a 
muffle, rifes in a white oxyd under the form of a vegeta¬ 
tion. One-half part of melted tin with two parts of co¬ 
balt, and the fame quantity of muriat of foda, furnifhed 
Baumc with an alloy in fmall clofe grains of a light vio¬ 
let colour. From equal parts of tin and bifinuth, by fu- 
iion, Geilert obtained a very brittle alloy, of a medium 
colour between thole metals, prefenting cubic facets in 
its fra&ure: but all the bifinuth does not mix with the 
tin, a fmall part is lod. 
Antimony, united to this metal, affords, according 1 to 
Geilert, a white and very brittle metal, whofe fpecific 
gravity is lei's than that of the two metallic fubltances 
taken leparately. Zink unites perfectly with tin, and pro¬ 
duces a hard metal of a clofe-grained fradlure, and more 
du6lile in proportion as the quantity of tin is larger. 
Mercury dill'olves tin with great facility, and in ail pro¬ 
portions. To make this combination, heated mercury is 
poured on melted tin ; the amalgam produced differs in 
l'olidity according to the relative dofes of thefe two me¬ 
tallic lubllances. 
An amalgam was formerly made with four parts of tin, 
and one of mercury, which were call into balls that be¬ 
came folid in cooling; thefe balls were lul'pended in wa¬ 
ter for the purpofe of purifying it. An operation fome- 
what fimilar to this is ufed in filvering looking-glalfes: 
a mixture of tin and mercury is applied, which amalga¬ 
mates immediately. 
Cold water has but little a£tion upon tin, but it tar- 
nilhes its furface in time; the well-water of Paris has 
this property in a peculiar degree. 
Tin diflblves in the fulphuric acid, whether concen¬ 
trated or diluted with water: when concentrated, ac¬ 
cording to Kunckel, it diffolves half its weight of tin. 
The lolution is performed very well by the abidance of 
heat. Sulphureous gas, of a very penetrating fmell, is 
difengaged, without any apparent eliervefcence or mo¬ 
tion. 
