802 
T I N‘ 
T I N 
85 parts of tin and 15 of phosphorus. Mar-' 
graf also formed this phosphuret, but he was 
ignorant of its composition. 
~ 'Fin does not combine with azote or mu- 
riatic acid; though the last substance con- 
verts it into an oxide. 
'f in is capable of combining with most of 
the metals, and some of its alloys are much 
employed. The greater number of them 
are brittle. The older metallurgists consi- 
dered it as a property of tin to render other 
metals brittle. Hence they called it diabolus 
metallorum. 
1 . It mixes readily with gold by fusion ; 
but the proportions in which these metals 
combine chemically are still unknown. When 
one part of tin and twelve of gold are melted 
together, the alloy is brittle, hard, and bad- 
coloured. Twenty-four parts of gold and one 
of tin produce a pale-coloured alloy, harder 
than gold, but possessed of considerable 
ductility. Gold alloyed with no more than 
of tin is scarcely altered in its properties, 
according to Mr. Alchorne; but Mr. Tillet, 
who more lately examined this alloy, found, 
that whenever it was heated it broke into a 
number of pieces. It is very difficult to 
separate these metals from each other. The 
method is, to fuse the alloy with sulpliuret 
of antimony. 
2. 'Fhe alloy of platinum and tin is very 
fusible and brittle, at least when these metals 
are mixed in equal proportions. Twelve 
parts of tin and one of platinum form an alloy 
possessed of considerable ductility, which be- 
comes yellow when expo edto the air. 
3. The alloy of silver and tin is v*ry brittle, 
hard, and durable. The two metals can 
scarcely be separated again by the usual pro- 
cesses. This alloy has been applied to no 
use. 
4. Mercury dissolves tin very readily cold ; 
and these metals may be combined in any 
proportion by pouring mercury into melted 
tin. The amalgam of tin, when composed of 
three parts of mercury and one of tin, cry- 
stallizes in the form of cubes, according "to 
Daubenton ; but, according to Sage, in grey 
brilliant square plates, thin towards the edges, 
and attached to each other so that the cavi- 
ties between them are polygonal. It is used 
to silver the backs of glass mirrors. See 
Foliation of looking-glasses . 
5. Tin unites very readily with copper, 
and forms an alloy exceedingly useful for a 
great variety of purposes. Of this alloy can- 
nons are made ; bell-metal ; bronze ; and the 
mirrors of telescopes, are formed of different 
proportions of the same metals. The addi- 
tion of tin diminishes the ductility of copper, 
and increases its hardness, tenacity, fusibility, 
and sonorousness. The specific gravity of 
the alloy is greater than the mean density of 
the two metals. It appears, from the expe- 
riments of Mr. Briche, that this augmenta- 
tion of density increases with the tin ; and that 
the specific gravity, when the alloy contains 
100 parts of copper and 16 of tin, is a maxi- 
mum: it is 8.87. The specific gravity of 
equal parts of tin and copper is 8.79, but it 
ought only to be 8 ; consequently the den- 
sity is increased 0.79. In order to mix the 
two metals exactly, they ought to be kept a 
jona- time in fusion, and constantly stirred, 
otherwise the greater part of the copper will 
sink to the bottom, and the greater part of 
the tin rise to the surface ; and there will be 
T I N 
formed two different alloys, one composed 
of a great proportion of copper combined with 
a small quantity of tin, the other ot a great 
proportion of tin alloyed with a small quantity 
of copper. 
Bronze and the metal of cannons are com- 
posed of from 6 to 12 parts of tin combined 
with 100 parts of copper. This alloy is 
brittle, yellow, heavier than copper, and has 
much more tenacity; it is much more tusible, 
and less liable to be altered by exposure to 
the air. It was this alloy which the antients 
used for sharp-edged instruments before the 
method of working iron was brought to per- 
fection. The yF.\**s of the Greeks, and per- 
haps the ces of the Koinans, was nothing else. 
Even their copper coins contain a mixture 
of tin. 
Bell-metal is usually composed of three 
parts of copper and one part of tin. Its co- 
lour is greyish-white; it is very hard, sono- 
rous, and elastic. The greater part of the 
tin may be separated by melting the alloy, 
and then pouring a little water on it. The 
tin decomposes the water, is oxidated, and 
thrown upon the surface. 
The mirrors of telescopes are formed by 
melting together three parts of tin and one 
part of copper. This alloy is very hard, of 
the colour of steel, and admits ot a fine po- 
lish. But besides this there are many other 
compounds used for the same purpose. 
Vessels of copper, especially when used as 
kitchen-utensils, are usually covered with a 
thin coat of tin, to prevent the copper from 
oxidating, and to preserve the food which is 
prepared in them from being mixed with any 
of that poisonous metal. These vessels are 
then said to be tinned. Their interior sur- 
face is scraped very clean with an iron in- 
strument, and rubbed over with sal ammo- 
niac. The vessel is then heated, and a little 
pitch thrown into it, and allowed to spread on 
the surface. Then a bit of tin is applied all 
over the hot copper, which instantly assumes 
a silvery whiteness. The intention of the 
previous steps of the process is, to have the 
surface of the copper perfectly pure and me- 
tallic ; for tin will not combine with the oxide 
of copper. The coat of tin thus applied is 
exceedingly thin. Bayen ascertained, that a 
pan nine inches in diameter, and three inches 
three lines in depth, when tinned, only ac- 
quired an additional weight of 2 1 grains. Nor 
is there any method of making the coat 
thicker. More tin indeed may be applied; but 
a moderate heat melts it, and causes it to run 
off. 
6. Tin does not combine readily with iron. 
An alloy, however, may be formed, by fusing 
them in a close crucible, completely covered 
from the external air. We are indebted to 
Bergman for the most precise experiments on 
this alloy. When the two metals were fused 
together, he always obtained two distinct 
alloys ; the first composed of 21 parts of tin 
and one part of iron ; the second of two parts 
of iron and one part of tin. The first was 
very malleable, harder than tin, and not so 
brilliant ; the second but moderately mal- 
leable, and too hard to yield to the knife. 
The formation of tin-plate is a sufficient 
proof of the affinity between these two metals. 
This very useful alloy is formed by dipping 
into melted tin thin plates of iron, thoroughly 
cleaned by rubbing them with sand, and then 
steeping them 24 hours in water acidulatec 
by bran or sulphuric acid. The tin not onlj 
covers the surface of the iron, but penetrate: 
it completely, and gives the whole a w hilt 
colour. See Tinning. 
The affinities of tin, and its oxides, are, ac 
cording to Bergman, as follow : 
Tin. 
Zinc, 
Mercury, 
Copper, 
Antimony. 
Gold, 
Silver, 
Lead, 
Iron, 
Manganese, 
N ickei. 
Arsenic, 
Platinum, 
Bismuth 
Cobalt, 
Sulphur. 
TiN-sfone, an ore of tin which occurs i 
masses, in rounded pieces, and crystallize! 
These crystals are very irregular. Colour tlar 
brown; sometimes yellowish grey, and som< 
times nearly white. Somewhat transparer 
when crystallized. Specific gravity 6.9 t 
6.97. Before the blowpipe it decrepitate! 
and on charcoal is partly reduced. Tingt 
borax white. According to Klaproth it ; 
composed of 
77.50 tin 
21.50 oxygen 
.25 iron 
.75 silica 
100.00 
TINCTURE. See Pharmacy. 
Tincture, in heraldry, the hue or colou 
of any thing in coat-armour. See Heralb 
ry. 
TINEA. See Medicine. 
TINNING. Tinning is the art of coVfei 
ing any metal with a thin coating of tii 
Copper and iron are the metals most con 
monly tinned. The use of tinning thes 
metals is, to prevent them from being coi 
roded by rust ; as tin is not so easily acte 
upon by the air or water, as iron and coppt 
are. 
What are commonly called tin-plates, o 
sheets, so much used for utensils of varioi 
kinds, are in fact iron plates coated with tii 
The principal circumstance in the art t 
tinning is, to have the surfaces of the met; 
to be tinned perfectly clean and free froi 
rust, and also that the melted tiy may b 
perfectly metallic, and not covered with an 
ashes or calx of tin. 
Tinning of iron. When iron plates ar 
to be tinned, they are first scoured, an 
then put into what is called a pickle, whic 
is sulphuric acid diluted with water ; ih 
dissolves the rust or oxyde that was left aftt 
scouring, and renders the surface perfectl 
clean. They are then again, washed an 
scoured. They are now dipped into a vesst 
full of melted tin, the surface of which : 
covered with fat or oil, to defend it from th 
action of the air. By this means, the iro 
coming into contact with the melted tin in 
perfectly metallic state, it conies out con 
pletely coated. 
Oxide of tin. 
Tartaric acid, 
Muriatic, 
Sulphuric, 
Oxalic, 
Arsenic, 
Phosphoric, 
Nitric, 
Succinic, 
Fluoric, 
Saclactic, 
Citric, 
Lactic, 
Acetic, 
Boracic,' 
Prussic. 
