TIN 
haps, no perfectty equable motion in all na- 
ture, it appears hence to follow, that abso- 
lute time should be something truly and 
really distinct from motion. But, accord- 
ing to Lucretius; 
“ Time, of itself, is nothing, but frcia 
thought 
Receives its rise ; by labouring fancy 
wrought 
From things consider’d, whilst we think 
on some 
As present, some as past, or yet to come. 
No thought can think on time, thats still 
contest. 
But thinks on tilings in motion, or at 
rest.” 
Time astronomical, is that taken purely 
from the motion of the heavenly bodies, 
without any other regard. 
Time cicil, is the former time accommo- 
dated to civil uses, and formed and distin- 
guished into years, months, days, &c. 
Time, in music, is an affection of sound, 
whereby we denominate it long or short, 
with regard to its continuance in the same 
degree of time. 
TIN, in mineralogy, a genus of metals, 
of which there are three species : 1. Tin- 
pyrites; colour intermediate between steel- 
grey and brass-yellow ; but usually more in- 
clined to the first ; it occurs massive and 
disseminated; internally it is glistening, 
sometimes shining, and seldom passing into 
splendent; its lustre is metallic ; it is brit- 
tle, and the specific gravity is somewhere 
between 4.3 and 4.8. Before the blow-pipe, 
it gives out a sulphureous odour, and melts 
easily, without being reduced, into a black 
scoria. It communicates a yellow or green 
<!blour to borax. It consists of 
Tin 
Copper 
Iron 
Sulphur 
Earth 
100 
It is found at Wheal-rock and St. Agnes 
in Cornwall, where it occurs In a vein about 
nine feet wide, accompanied v^ith copper 
pyrites and brown blende. 
t. Tin-stone, which is hard, brittle, and 
very heavy, the speeifie gravity being from 
5.8 to 6.9 or 7. Before the blow pipe it 
decrepitates, becomes paler, and, where it 
rests on the charcoal, is reduced. AFhen 
roasted, it is converted into a grey oxide. 
. TIN 
A specirsen, analysed by Klaproth, con- 
tained 
Tin 
Iron 
Oxygen 
Silica 
100.00 
It occurs only in primitive rocks, as gra- 
nite, gneiss, mica-slate, and clay-slate, and 
is said to be the oldest of all the metals. It 
occurs either disseminated in the rock, or in 
beds, or veins. It is usually accompanied 
with quartz, mica, &c, and is also found in 
great quantities in alluvial land. The greater 
part of tiie English, much of the Spanish, 
and the greater proportion of that from In- 
dia, occurs in that situation. 
Tin is npt found in many countries ; but 
where it exists at all, it is in very consider- 
able quantities. In Europe there are only 
three tin districts : the first is in Saxony 
and Bohemia ; the second in Coniwall ; ami 
the tiiird is that of Gallicia, on the borders 
of Portugal. It is found in many parts of 
Asia, and in South America. It is worked 
as an ore of tin, and from it all the tin of 
commerce is obtained. Its name is derived 
from' the quantity of tin which it affords, 
and its unmetallic aspect. 
3. Cornish tin-ore, or w'oqd tin ; which, 
like the last, is very heavy ; before the blow- 
pipe it is infusible ; it consists of about 63 
parts of tin, with iron and arsenic. It has 
hitherto been found only in Cornwall, and 
there in alluvial land. It is very like brown 
hematite, from which it is distinguished by 
its colour, its rolled pieces, greater hard- 
ness, and higher specific gravity. We now 
turn to tin, in a chemical view. 
Tin ^ a inetal of a silver-white colour, 
very ductile, and malleable, gives out, while 
bending, a crackling noise, is fusible at a 
heat much less than that of ignition, is solu- 
ble in muriatic acid, and, by dilute nitric 
acid, is rapidly converted into a white ox- 
ide. Tin has been known from the earliest 
ages. It was much employed by the Egyp- 
tians in the arts, and by the Greeks as an 
alloy with otlier metals. Pliny speaks of it 
under the name of white lead, as a metal 
well known in the arts, and even applied in 
the fabrication of many ornaments of lux- 
ury. He ascribes to the Gauls the inven- 
tion of the art of tinning, or covering other 
metals with a thin coat of tin. The alche- 
mists were much employed in their re- 
searches concerning tin, and gave it the, 
