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whiting, and a little more than one part of common salt. 
After the surface of the. brass, cleared from scratches, has 
been rubbed with a piece of old hat and rotten stone, in 
order to remove any grease, and then moistened with salt 
and water, a little of the composition, being now rubbed on 
with the finger, will presently cover the surface of the metal 
with silver. Then wash it well, rub it dry with soft rag, 
and then, as the coat of silver is very thin, cover it with 
transparent varnish to preserve it from tarnish. As this kind 
of silvering is very imperfect, it is only used for the faces of 
clocks, the scales of barometers, or similar objects. The 
third mode of performing this operation is by means of silver 
in substance: and of doing this there are three different 
methods. The first is by mixing together 20 grains of silver 
precipitated by copper, two drachms of tartar, two drachms 
of common salt, and half a drachm of alum. Now rubbing 
this composition on a perfectly clean surface of copper or 
brass will cover it with a thin coating of silver, which may 
be polished with a piece of soft leather. Another and better 
method, called French plating, consists in burnishing down 
upon the surface of the copper successive layers of leaf-silver 
to any required thickness. Although the silver in this ope¬ 
ration is more solid than in any of the former modes, the 
process is tedious, nor can the junctures of the leaves of silver 
be always entirely concealed. 
Brass may be silvered, by boiling it with filings of good 
pewter and white tartar, in equal quantities. 
Silvering in the cold is performed by the following com¬ 
positions : 31bs. of cream of tartar; 31bs. of common salt; 
and 1 oz. of muriate of silver, which is the precipitate 
formed by adding common salt to nitrate of silver, till no 
more is precipitated. This composition is made into a 
pulp. The surface of the copper or brass to be silvered 
must first be cleaned with diluted acid, and then made dry, 
and kept free from grease. The surface, being now rubbed 
with the above paste, will assume a white colour, by the 
silver adhering to it. This process is generally employed 
for silvering clock-faces, and the scales of instruments. The 
surface should always be varnished to prevent its tarnishing, 
as the silver is too thin to bear cleaning. 
Silvering of Mirrors, is the application of a coating of 
quicksilver to their posterior surface. A perfectly fiat slab 
of free-stone (or sometimes of thick wood), a little larger 
than the largest plate, is inclosed in a square wooden frame 
or box, open at the top, and with a ledge rising a few inches 
on three sides, and cut down even with the stone on the 
fourth. A small channel or gutter is cut at the bottom of 
the wooden frame, serving to convey the waste mercury 
down into a vessel below, set to catch it. The slab is also 
fixed on a centre pivot, so that one end may be raised by 
wedges (and of course the other depressed) at pleasure, when 
working freely in the box. 
'1 he slab being first laid quite horizontal, and covered with 
grey paper stretched tight over it, a sheet of tin-foil, a little 
bigger than the plate to be silvered is spread over it, and 
every crease smoothed down carefully; a little mercury is 
then laid upon it, and spread over with a tight roll of cloth, 
immediately after which as much mercury is poured over it 
as will lie on the flat surface without spilling. That part 
of the slab which is opposite the cut-down side of the 
wooden frame is then covered with parchment, and the 
glass plate is lifted up with care and slid in (holding it 
quite horizontally) over the parchment, and lodged on the 
surface of the slab. The particular care required here is, 
that the under surface of the glass should from the first just 
dip into the surface of the mercury (skimming if off as it 
were), but without touching the tin-leaf in its passage, 
which it might tear. By this means no bubbles of air 
can get between the glass and the metal, and also any little 
dust or oxyd floating on the mercury is swept off before the 
plate without interfering. The plate being then let go, 
sinks on the tin-foil, squeezing out the superfluous mercury, 
which passes into the channel of the wooden frame above- 
mentioned. The plate is then covered with a thick flannel, 
and is loaded over the whole surface with lead or iron, 
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weights, and at the same time is tilted up a little, by which 
still more of the mercury is squeezed out. It remains in this 
situation for a day, the slope of the stone slab being gra¬ 
dually increased to favour the dripping of the mercury. 
The plate is then very cautiously removed, touching it only 
by the edges and upper side, and the under side is found 
uniformly covered with a soft pasty amalgam, consisting of 
the tin-leat thoroughly soaked with the quicksilver, and 
about the thickness of parchment. It is then set up in a 
wooden frame, and allowed to remain there for several days, 
the slope of its position being gradually increased, till the 
amalgam is sufficiently hardened to adhere so firmly as not 
to be removed by slight scratches, after which the plate is 
finished and fit for framing. 
SI'LVERLING, s. A silver coin.—A thousand vines, at 
a thousand sliverliugs, shall be for briars and thorns. 
Isaiah. 
Sl'LVERLY, adv. With the appearance of silver. 
Let me wipe off this honourable dew 
That silver/y doth progress on thy cheeks. Shakspeare. 
SILVERMINES, a village of Ireland, now ruinous and 
deserted, though bearing evident marks of having formerly 
been populous. In the stupendous mountains overhanging 
this village, rich veins of lead ore have been discovered, 
and for some considerable time profitably wrought; 77 miles 
west-south-west of Dublin. 
SI'LVERSMITH, s. One that works in silver.—Deme¬ 
trius, a silversmith, made shrines for Diana. Acts. 
SILVER.STONE, a village of England, in Northampton¬ 
shire ; 3 miles from Towcester. Population 696. 
SI'LVERTHISTLE, s. [acanthium vulgare, Lat.] A 
plant. Miller. 
SILVERTON, a parish of England, in Devonshire; 5| 
miles south-west of Columpton. 
SI'LVERY, adj. Besprinkled with silver. 
Of all the enamell’d race whose silvery wing 
Waves to the tepid zephyrs of the spring, 
Once brightest shin’d this child of heat and air. Pope. 
SILVES, a small town of the south of Portugal, in Al- 
garva, on the river Silves, which is navigable as far as this 
town. It has only 2000 inhabitants, but its circuit is capa¬ 
ble of containing, as it formerly did, a much greater number. 
It was also a bishop’s see for 400 years, but this dignity was 
transferred to Faro in 1580. The environs are very pleasant; 
24 miles east-north-east of Lagos, and 45 west-north-west of 
Tavira. 
SILVESTRE GRANUM, or Coccus Silvestris, a 
term used by some authors to express the coccus Polonicus ; 
and by others, for a coarse or bad kind of cochineal. 
SILV1NGTON, a parish of England, in Salop; 8| miles 
north-east of Ludlow. 
SILURES, or according to the orthography of Ptolemy, 
Sylures, a people of the isle of Albion, who possessed, 
besides the two English counties of Hereford and Mon¬ 
mouth, Radnorshire, Brecknockshire, and Glamorganshire, 
in South Wales. The northern part of Herefordshire has 
been supposed by some to belong to the Ordovices. The 
name of this ancient British nation is derived, by some of 
our antiquaries, from coil, a wood, and ures, men, because 
they inhabited a woody country; and by others, from the 
British words es heuil ilir, which signify brave or fierce 
men. Tacitus has conjectured, with little probability, and 
no sufficient evidence, that the Silures had come originally 
from Spain, grounding the conjecture on a supposed, or 
perhaps fancied resemblance betweeen them and the ancient 
Spaniards, in their persons and complexions. 
SILURUS, [from the words c-eia-, to move or shake, and 
ovya, a tail-, this fish, being almost continually moving 
its tail in the water,] in Ichthyology, a genus of fishes of 
the order abdominales, of which the Generic Character is as 
follows: —The head is naked, large, broad, and compressed; 
the mouth is furnished with cirri, resembling the feelers of 
insects; 
