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SIDE-SADDLE FLOWER-SIERRA NEVADA

The iron in the clay iron stones is generally in this See IRON, METALLURGY OF.

saddle Flower. See PITCHER PLANT.

wick, HENRY, LL.D., D.C.L., b. 1838. Prof. Cambridge
ethods of Ethics, 1874; Political Economy, 1883; Hist.
886; Politics, 1891.

outh, HENRY ADDINGTON, VISCOUNT, 1757-1844. M.P.
eaker 1789-1801; Premier 1801-4; Viscount 1805; Privy
5-7; Home Sec. 1812-21; reactionary.
ey, or Sydney, ALGERNON, 1622-1683.
entary army; Gov. of Dublin 1646; a judge at the
Officer in
Charles I. 1648; member of Long Parliament, of
of State, and Ambassador to Denmark 1659; in
til 1677; charged with high treason (Rye House
83, and beheaded Dec. 7.
ent, 1698.
Discourses concerning

y, SIR PHILIP, 1554-1586. English poet and courtier,
and remembered not more for his gifts and accom-
ts than for the beauty of his character; knighted
rtally wounded at Zutphen, fighting for Dutch liberty.
ance, Arcadia, Defense of Poesy, sonnets, psalm ver-
d songs appeared posthumously, and were collected

1. Long most powerful, and perhaps oldest, city of , on the coast ab. 22 m. n. of its colony, TYRE (q.v.),

1389

down the permanent defenses of a fortified place, and to destroy or dismount its armament. These are, in the U. S. tively; the projectiles for them weigh 45, 105, and 125 lbs. service. 5-in. and 7-in. steel breech-loading rifles and 7-in. steel mortars, weighing 3,660, 3,710, and 1,715 lbs. respecrespectively.

Siege Carriages. The 5-in. gun and 7-in. howitzer carriages are mounted on wheels and when united to their limbers form wheeled carriages. nected with platform by hydraulic buffers to check recoil. When in place the carriage is conThe mortar carriage is not wheeled; when in position it rests springs inclosed in a strong case. on three traverse circles to obtain the proper azimuth for firing, and its recoil is checked by hydraulic buffers and coiled

Siegfried. See NIBELUNGENLIED.

Siemens, SIR WILLIAM, F.R.S., 1823-1883. German engineer and electrician, in England from 1844. His greatest invention is the regenerative gas furnace, invented with his brother took up making steel by fusing malleable iron with cast-iron, Friedrich 1857, and first successfully applied 1861. In 1862 he and after several years perfected the Siemens' steel process. signed the steamer Faraday, which laid the first transatlantic He was one of the earliest workers at the electric light, decable, devised an electric furnace, an electric pyrometer, a direct process of making iron and steel from their ores, and a regenerative gas-burner.-His brother ERNST WERNER, 18161892, shared in several of his inventions.

Siena, GUIDO DA, 13th cent. Italian painter.

Sienkiewicz, HENRYK, b.1845. Polish novelist; ed. Slowo, 1880. With Fire and Sword, 1884. The Deluge, 1890, and Pan Michael, tr. 1894, form a long historical romance of great power. Pisma, 1880; Without Dogma, tr. 1894; Quo Vadis,

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Sienna. Old Tuscan city, 60 m. s. of Florence, with which it was long at war; besieged and taken by imperial troops

it was eclipsed; famed for its maritime power and for ufacture of glass: conquered by Cyrus ab.537 B.C.; om the pasha of Egypt by Turkey, aided by British ot. 1840.

ius Apollinaris, ab.430-483.

ngebirge. Seven mountains in Rhenish Prussia ght bank of the Rhine 20 m. above Cologne. The Olberg, 1,522 ft., and the most famous DRACHEN

-).

d, PHILIPP FRANZ VON, 1796-1866. German botanpan 1823-30; Dutch Baron 1831. Flora Japonica, His brother, KARL THEODOR ERNST, 1804-1885, mich 1853, wrote on natural history. Invertebrata,

Operations of placing an army before a military and attempting its capture by the method of reguaches. Lines of circum- and counter- vallation are plished as a security against sorties from the besieged cks from the enemy's forces from without. After tment is complete and depots are established the lel is constructed. This is a line of intrenchment of extent to embrace at least the capitals of the two djacent to that of attack. At least three parallels ed, although there are instances of five or more have necessary: the first should be beyond the destrucon range of the besieged, the second at the limit of rous zone of small-arm fire, and the third where the ction of the double sap is needed to protect the sapthe direct front and slant fire of the infantry. Cone parallels and advancing upon the capitals are the boyaux, by means of which the besiegers are enabled Found toward the fortified place.

1555; held by Florence from 1557; once an important art cen-
ter; noted for its duomo or cathedral. Its univ. was founded
1203. Pop. ab.28,000.

speaking countries.
Sierra. Applied to a range of mountains in Spanish-

low and unhealthy, rising inland into hills. The rainfall
Sierra Leone. British colony on w. coast of Africa, w.
of Liberia; area ab.15,000 sq. m. Along the shore the land is
reaches 170 in. annually. Pop., 1890, 75,000, including 224
whites, the balance negroes, one-half of whom are the descend-
ants of liberated slaves.

Sierra Madre. Mountain range of w. Mexico, extend-
ing from the U. S. border to Guadalaxara, ab.300 m.; height
seldom over 10,000 ft.

Sierra Morena. Mountain

SIEVE-CELLS-SIGN MANUAL

titude 11,660 ft. 2. Principal range of Cal. most of the e. border, with long spurs dehe valley of Cal., and a short precipitous ight increases s., and reaches its maximum Lear its s. end, 14,898 ft.

Elongated cells of the fibro-vascular system erized by their walls being finely perforated Fined panels or plates, called sieve-plates; also e-cells and sieve-tubes.

AMALIE, 1794-1859. Founder of a nursing sisurg 1832, nucleus and model of others through

to any height corresponding to a given range or elevation: the
notch has also a motion at right angles to the rod to correct
for drift, wind velocity, or other causes of lateral deflection.
The sights used in small arms consist of a fixed point of metal
for the front sight and a graduated metal leaf carrying a notch
arranged for adjustment for all ranges.

Sigillaria. Genus of extinct LEPIDODENDREÆ (q.v.).
Sigillum Confessionis. Seal of confession. In R. C.
Ch., the obligation of a confessor not to divulge the secrets
of the confessional.

Sigismund, 1368-1437. German emperor from 1411; son of
Charles IV.; King of Hungary 1387; defeated at Nicopolis, by
the Turks, 1396; imprisoned by the usurper Ladislaus of Naples,
He convoked the Council of Constance 1414; con-
1401-3.
sented to the condemnation of Huss, in violation of his own
sen. Near Hanover; scene of a defeat of Al-safe-conduct; sold Brandenburg to Frederic of Zollern, and

Prof. Jena 1876, Tübingen 1883,
ARD, b. 1850.
Leipzig 1892; prolific writer on philology. An-
mar, 1881, tr. 1887.

ch, 1553, by the imperial troops under Maurice was slain.

es. See SIEVE-CELLS.

defeated the Turks, 1416 and 1419. His succession to the Bo-
hemian throne, 1419, was successfully resisted by the HUSSITES
He did
(q.v.), but obtained 1436, by concessions to the Calixtines, which
he afterward withdrew. His death averted civil war.
little for the empire.

King of Poland from 1507;

ANUEL JOSEPH, 1748-1836. French priest, who,
on human rights and the Third Estate, 1788-89,
uenced the early course of the Revolution; Dep-able and prosperous ruler, patron of letters and of the Ref-
of the Directory 1799, and of the three Consuls,

Emmanuel Joseph Sieyes.

lanned the movement of 18th Brumaire with Bonaho made him a count. Thinker rather than politiservant of fixed ideas, he bore no part in the Reign , lived in retirement under Napoleon, and was in exile

FRANZ, b. 1824.

Leader in German insurrections in America from 1852; Brig.-gen. U. S. Vols. 1861, en. 1862-65; prominent in Mo. and Va.; journalist, lecnd official in New York since 1867.

ing. Deep and long-drawn inspiration chiefly through e, followed by a somewhat shorter, but correspondingly nd audible expiration; it is manifested frequently durfound mental impressions, as of grief.

ormation.-II. (AUGUSTUS), 1520-1572, his son and worthy
successor.-III., 1566-1632; his nephew, King of Poland
1587, and of Sweden 1592-1604. His reign was warlike and
injurious.

at. SENSATIONS OF. Changes of consciousness aroused mulation of the retina of the eye; of two distinct kinds, ions of light, supposed to be due to rapid vibrations of pus ether, and of color, due to differences in rapidity of ion. Sight is probably the most presentative of all the by which we acquire direct knowledge of the external See EYE, AFTER IMAGES, COLOR, COLOR-BLINDNESS, LE IMAGES, and HOROPTER.

hts. Attachments used for pointing a gun. The front is a fixed point, a thin edge, or cross wires in a protectthe rear sight consists of a rod, bar or standard, in a socket on the breech

Sigmaringen. See HOHENZOLLERN.

Sigmoid. In Botany and Geology, S-shaped structures. Signay, JOSEPH, D.D., 1778-1850. Bp. of Quebec 1833; Abp. of the province 1844.

Sign. Symbol of operation, direction, character, relation,
as distinguished from symbols of quantity or mere abbrevia-
tions.

Signal Code. Signals by means of which messages may
be sent in the presence of the enemy without being intelligible
to them. The code is usually based upon a small number of
elementary signals; that of the army is one of three elements,
a motion to the right, one to the left, and a forward motion.
The first two signals, designated 1 and 2, may by combination
give all the letters of the alphabet and the third designate the
completion of a word or sentence. The code may be trans-
mitted by flags, torches, semaphores or telegraph. The signals
are interpreted by a signal book.

Signal Service. Organization for display of signals for
any purpose; especially, meteorological branch of office of
Chief Signal Officer U.S.A., the military duties of which were
imposed on it 1862: the meteorological work was added in
February 1870. The chief is by law a brig.-gen. The chiefs
have been: A. J. Meyer 1862-80; Wm. B. Hazen 1880-87; A.
W. Greely, since 1887. The meteorologists have been: Wm.
Ferrel, 1881-87, Cleveland Abbé, since 1871. By act of Con-
gress all the meteorological duties of this service were July
1, 1891, transferred to the new weather bureau of the De-
partment of Agriculture.

Signature. In Printing, the figure or letter at the lower gathering of the sheets for binding them.-Also the sheet part of the first page of a sheet, intended to facilitate the when folded ready to gather.

Signature of Plants. In early medicine, a belief that the external formation or color of plants indicated that they were adapted for particular diseases; as Lungwort and Liverwort.

Sign Boards. House signs were indispensable in city life when few could read and write. As education spread, they were less needed, and when the system of numbering houses was introduced in the last century, their original value lingered on, usually as business advertisements. Sign boards appear to have been adopted from the Romans, examples of whose pictorial signs have been excavated at Herculaneum. See SHOP SIGNS.

Signet. In England, the king's seal, used in sealing his private letters, and all such grants as pass his majesty's hand by bill signed.

Significant Figures. In Arithmetic, those having quantitative value; distinguished from zero and other symbols of position in the scale.

Sign Language. See DEAF MUTES.

Sign Manual, ROYAL. The signature or subscription of
tomed the sign manual. This is done

as a personal act of t employed it is an act Signorelli, Luca, fre astic student of the He has angelo.

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union of the Apostles-Cathedral of Cortona, by Signorelli.
His great work is the series of frescoes in the
f the cathedral of Orvieto painted after 1499.
ng them he was assisted by his pupil Girolamo

ney, LYDIA HOWARD (HUNTLEY), 1791-1865. Ameri-
once very popular. Letters of Life, 1866.
aza y Gongora, CARLOS, 1645-1700.

Mexican

rt, CHRISTOPH VON. Ph.D., b. 1830. Prof. Tübingen gic, 1873-78, tr. 1894.

WILLIAM WIRT, 1836-1883. U. S. Consul at Cardiff 5 journalist and author.-His wife, OLIVE (LOGAN), 1871, is an actress and writer.

Sect in India, rejecting idolatry and caste distincinfusing much of Buddhism and Mohammedanism aism; founded by Nanak, a Hindu, 1469-1538. They great military power in the 18th century; but subthe English 1848, when the Punjab was annexed to empire, and furnish ab. 14,000 soldiers to the Brit

Fodder material preserved in the fresh state by the process of ENSILAGE (q.v.). It usually

the name of the fodder so preserved: e.g., corn ver silage. The former is the best silage plant

a.

. Satyr, companion and instructor of Bacchus; h the power of prophecy; represented as a fat, 1, old man, intoxicated, and often riding on an

S.e. province of Prussia; early occupied by German ceeded, as they moved w., by Slavs; joined, succesMoravia, Bohemia, and Poland; separated from Pobut ruled by dukes of the Piast line, who encouran colonies; then held by Bohemia, and thus conh Germany. An agreement of succession, made Prussia heir to parts of it; but Austria seized them fief of Bohemia, the remaining portions having preen to her. This claim was resisted by Frederick II., The SEVEN YEARS' WAR (q. v.), Silesia was ceded, 1763, Capital Breslau. Area 15,557 sq. m.; pop., 1890,

AUSTRIAN. Duchy and crown-land in the n.e. of province of Austrian empire. Area 1,987 sq. m.; 602,117.

, ANGELUS. See SCHEFFLER, J. See SILICA.

ette. Profile drawn in black, the shadows and exhs being indicated by the heightening effect of gum

Silhouette Portraits.

for reforms in the interest of economy. Silhouettes were known to the ancients, as is shown on vases.

Silica. SiO,.

and oxygen, occurring in nature by itself in the three forms of Chemical compound consisting of silicon quartz, opal, and tridymite, and in combination with various bases in the class of minerals known as silicates; made by melting sand with sodium carbonate, and treating with hydrochloric acid; insoluble in water and the ordinary acids, soluble in alkalies and hydrofluoric acid; fusible with difficulty; found in plants, straw, and eggs; used extensively in the manufacture of glass and porcelain.

land, as made at the present. Owing to sulphur in furnace Silicate Cotton. This was first made by a steam-blast slags, which when wetted would corrode iron, rocks are fused on a stream of melted slag; invented by John Player, of Engand treated in the same manner, 4 parts of orthoclase with 6 parts of dolomite. It is usually white, and is used as a nonconductor to prevent freezing of water pipes, cooling of steam pipes and dampness in buildings, to keep out vermin, and to prevent the spread of fire, it being non-combustible. It came into general use 1871. It occurs in nature as PELE'S HAIR (q.v.).

Silicates. Derivatives of silicic or of the polysilicic acids; family of minerals, numbering several hundred species, consisting of silicon and oxygen, combined in many different proportions with aluminium, calcium, magnesium, sodium, potassium, iron, and many other chemical elements. Except sandstones and limestones, almost all the common rocks are made up to a large extent of silicates.

Silicic Acids. These are numerous. All may be regarded
as derived from normal silicic acid, Si(OH),. The simplest form
is H,SiO,, made by decomposing a silicate in solution with
dilute hydrochloric acid. When the solution is evaporated to
dryness, the residue is no longer soluble.
H.Si,O, is derived from two molecules of the ordinary form
Disilicic acid,
by abstracting one molecule of water; trisilicic acid, H.Si,O10,
from three molecules of the ordinary acid by abstracting two
molecules of water. Other trisilicic acids are derived in a
similar way. Many minerals are derivatives of some form of
silicic acid.

Silicide of Carbon. See CARBORUNDUM.

Silicified Wood. Wood in which the organic matter has been removed and its place taken by silica, usually in the form of agate (agatized wood), or of opal. Tree trunks, three or four feet in diameter or more. have been found in considerable quantity in the silicified condition in Arizona and elsewhere. When polished, these masses exhibit a beautiful variety of colors. See PETRIFIED WOOD.

Silicle. Short form of the fruit called a silique, found in
Peppergrass, Shepherd's Purse, and other plants of the Mus-
tard family.

Silicon. Si. At.wt. 28.4, sp. gr. 2.49
IV.: discovered

sn ht

100

SILICON BROMOFORM-SILOAM

t of the earth's crust, probably one-fourth. It lized and amorphous forms. The former may ng potassium fluosilicate with sodium and zinc. orphous powder, it is obtained by passing the tetrachloride over heated sodium. Amorphous solved by sulphuric or nitric acids, but is readily ofluoric acid and potassium hydroxide. comoform. SiHBr,. Colorless liquid, sponmmable in the air; bpt. 115-117° C.; sp. gr. treating silicon chloroform with hydrobromic s to bromoform, CHBr,. arbide.

SiC. Transparent, rhombic tablets, ster, not soluble in the common acids; decomon with caustic alkalies; hardness 9.5, sp. gr. y treating silica with carbon at a temperature ; used for polishing purposes and for the manuishing apparatus. See CARBORUNDUM. Chloroform. SiHCl3. Colorless, mobile, fuma strong odor, very inflammable and unstable; account of its compositional resemblance to Hexabromide. Si,Br.. Liquid boiling at 240° C. white substance with water, and is made by the omine upon silicon hexiodide dissolved in carbon Hexachloride. Si,Cl, Colorless, mobile, fumbpt. 146°-148° C. It solidifies at 14° to large white stals. It is made by passing the tetrachloride over

n.

Hexiodide, Si,I,. Colorless, doubly refracting rhombohedra; mpt. 250° C. (in vacuum); made by e tetraiodide with finely divided silver to 290°-300° C. Hydride. SiH,. Colorless gas, made by treatpound of magnesium and silicon with hydrochloric pared in this way, it takes fire in the air.

Colorless, strongly refracIodoform. SiHI,. d; bpt. 220° C., sp. gr. 3.36; made by passing hydriodic ver heated silicon.

n Tetrabromide. SiBr. Colorless, fuming liq149° C., sp. gr. 2.81; made by heating the elements

n Tetrachloride, SiCl4. Acrid, fuming, colorid, made by passing chlorine over a strongly heated of silica and charcoal; decomposed by water. on Tetrafluoride. SiF. Strongly fuming, colorof a pungent odor, made by treating calcium fluoride ea with sulphuric acid.

on Tetraiodide.

Sil,.

Colorless, transparent, octahedra, isomorphous with carbon tetraiodide; 0.5° C., bpt. 290° C.; made by passing iodine vapors eated silicon.

coskeleta. Sub-class of Radiolaria, including the PERIPYLEA, MONOPYLEA, and PHEODARIA (q. v.). culosa. Order of the Linnæan class Tetradynamia, ng those cruciferous plants which bear short round alled silicles.

sians 1854 and many times assaulted in vain. June 15th the
garrison assumed the offensive, crossed the river, defeated the
Russians, destroyed the siege works, and raised the siege. Its
of Berlin, 1878. Pop., 1893, 11,710.
principal redoubt was ordered to be destroyed by the Congress

Silius Italicus, 25-101. Latin epic poet, Consul 69.
His Punica, in 17 books, describing the second Punic
war, is extant. His meter is good, but the work is too
close an imitation of Virgil and Homer to claim much
originality.

que. Two-valved, capsular fruit, each valve having a
al placenta, from which the valves break away when
e, as in many plants of the Mustard family.
iquosæ. Order of the Linnæan class Tetradynamia,
ling those cruciferous plants which bear elongated,
er pods called siliques.

istria. Town of Bulgaria on the Danube; besieged in

Silistria.

Silk. Fine, lustrous fiber produced by the larvæ of certain
moths, the best by the Silkworm (see BOMBYCINA), an annual,
and a native of China. The moth is white, about 1 in. long,
and lays many eggs, as large as mustard seeds. About six
weeks after hatching the worm begins to spin the cocoon,
which is completed in a week. The worm is 3 in. long, of a
cream color, and feeds on white-mulberry leaves. The silk is
produced by the two glands opening in the underlip. The
cocoon is egg-shaped, and about 1 in. long. An equal num-
ber of male and female cocoons are selected for breeding, the
latter being the larger, and placed in a room ab. 70° F., when
the moth develops, lays its eggs, and dies. The diseases of the
silkworm are muscadine, due to a fungus, and pebrine and
flacherie, due to bacteria; they have entailed great losses on
silk growers. Pasteur suggested remedies, which have been
in hot water or an oven to kill the chrysalis. The fiber is as
fine as in. diameter, each cocoon yielding ab. 300 yds. The
largely efficacious. The remainder of the cocoons are placed
outer floss silk is separated, the cocoons floated in hot water
and the silk reeled off, 2 to 6 cocoons being run into one thread.
The cocoons yield ab. 10 per cent of raw silk. The raw silk
contains up to 25 per cent of gum, which is removed by boiling
with soap. The silk is used in the raw and in the boiled state,
several threads being twisted into one. It is dyed in the thread,
or in the piece after weaving. The fabrics are often loaded
with tannic acid and metallic salts in the dyeing to increase
their weight. The world's annual production of raw silk is
half, Italy one-third, and France, the Levant and India the
balance. The annual silk manufactures of the world are
estimated at 30,000,000 lbs., China and Japan furnishing one-
valued at $320,000,000, of which $120.000,000 are by France,
$80,000,000 by the U. S., Switzerland and Germany each
$20,000,000, and England $5,000,000; Japan also largely man-
ufactures. In 1896 there was imported into the U. S. silk
manufactures valued at $26,652,768, and unmanufactured silk
valued at $26,753,428. The price of raw silk in New York,
Jan. 1898, was from $2.25 to $4.50 per lb. Good silk, rated
as No. 1, was from $3.50 for Japanese to $3.90 for Piedmont,
Italian.

June 30. 1829,

Silk. maize.

In Botany, long styles of the flowers in an ear of

Silk-Cotton Trees. Of the Mallow family, of the genera Bombax, Pachira and Eriodendron, natives of tropical Asia and America, bearing very large flowers and seeds provided with long, silky hairs.

Silkweed. See MILKWEED.
See BOMBYCINA.
Silkwor m.

Silkworm Gut. Material prepared in Italy and Sicily, and used by anglers for dressing the hook end of a fishing line. The worms, about to begin spinning, are immersed in vinegar for ab. 12 hours, when they are pulled apart, exposing two transparent yellowish-green cords, which are stretched on a board to dry.

Sill. In Mining, horizontal piece of timber laid to support the vertical or inclined legs of a set of timbers.

Sill, EDWARD ROWLAND, 1841-1887. Prof. Univ. Cal. 1874-82;
poet.

Sill, JOSHUA WOODROW, U.S.A., 1831-1862. Brig.-gen. U.S.
Vols.; killed at Murfreesboro.

Village near Rheims, France, famous for its
Sillery.
champagne. Pop. 400.

Prof. of

Silliman, BENJAMIN, M.D., LL.D., 1779-1864.
Chemistry at Yale 1802-53: founder of its museum of geol-
ogy, and of the American Journal of Science and Arts, 1818;
eminent as a physicist and geologist. Chemistry, 1830.-His
son. BENJAMIN, M.D., LL.D., 1816-1885, was Prof. Yale from
1846, co-editor Journal of Science from 1845, and author of
several text-books and many monographs.

Sillimanite. Al,SiO. Aluminium silicate, commonly
found as an accessory ingredient in several kinds of met-
amorphic rock; also called fibrolite.

Silo. See ENSILAGE and SILAGE.
Siloam.

Fountain and pool of Jerusalem, connecting
second pool by an aqueduct, mentioned in O. T. and

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Siluridæ. See NEMAT Silva, ANTONIO JOSÉ D b. in Brazil; burned at L Jews.

Silva, José LAURENC prominent in the liberatic 1828; exiled 1831-35; Lieu

Silva Lisboa, José and statesman, Senator 18 1840, pub. Annals of Rio J Silver (ARGENTUM). 057, mpt. 954° C., valence A ogens, forming insoluble chloric acid, it becomes c chloride. It is soluble in best solvent is nitric aci ware. Its salts, which ar tography.

Silver, METALLURGY in the following ores: Na Proustite. and Čerargyrit other ores with sulphur, a found in small amount in tetrahedrite. Pure silver

ductile, the best known co mpt. is 954 C.; it boils be and has been distilled; its by transmitted light. When melted, it absorbs 2 It it gives out suddenly whe does not oxidize in dry or vapors containing sulph loys easily with melted metals; it dissolves in

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SILT-SILVER

It is intermittent. Here in 1880 a Hebrew inscription nd, dating from ab.700 B.C., describing the making of

1393

The

Three principal methods are used in treating the ores. most usual is to smelt the silver ore together with lead ore, the lead obtained carrying all the silver. This may be accomplished in any of the ways used for treating lead ores (see LEAD, METALLURGY OF). This silver-bearing lead can be desilverized by several processes. Another method is to convert the silver into chloride, then dissolve this in a salt solution, from which it is afterward precipitated. Another is to amalgamate the silver by grinding the ore up with mercury, and distilling the mercury from the amalgam.

Amalgamation processes are very old, and are conducted as follows: the barrel amalgamation makes use of tight, revolving barrels. If the ore is not native silver or the chloride, it is first roasted with common salt, which converts the silver into chloride. The charge of a barrel, in Freiberg, was 1,500 lbs. of roasted ore, 300 lbs. of water, 120 lbs. of lumps of iron. The barrel was turned 12 times a minute for 2 hours, then stopped, and 300 to 500 lbs. of mercury put in, and ro

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from a spring to the pool. In 1889 a second conduit overed 20 ft. below the ground.

Fine, impalpable mud collecting in lakes and estuaries; calm and gradual deposits of mud, clay, or fine sand. es. Ancient people, probably of a non-Aryan stock, -k and curly-haired, inhabiting the s.e. of South Wales. e warlike and resisted fiercely the Roman generals ded their territory.

an. Series or system of fossiliferous rocks lying imbelow the Devonian; first studied in Wales by Mur-ho named them from the Silures, an ancient British his term has been gradually restricted, and is now nly to Murchison's upper division, the lower being dovician. See COLUMN.

ew York.

daga

ara

on

да

la

dæ. See NEMATOGNATHI.

ANTONIO JOSÉ DA, 1705-1739. Portuguese dramatist, zil; burned at Lisbon, with his mother and wife, as

JOSÉ LAURENCIO, 1792-1873.

t in the liberation of Colombia and Peru; Major-gen.
Venezuelan officer,
ed 1831-35; Lieut.-gen. and Sec. of War 1855.
Lisboa, JosE DA. 1756-1835. Brazilian historian
sman, Senator 1826.-His brother, BALTHAZAR, 1761-
Annals of Rio Janeiro, 7 vols., 1834.

(ARGENTUM). Ag. At.wt. 107.92, sp. gr. 10.5, sp. ht.
954° C., valence I. It unites directly with the hal-
ming insoluble compounds. Treated with hydro-
id, it becomes covered with a layer of the insoluble
It is soluble in concentrated sulphuric acid; the
ent is nitric acid. It is used for coins and silver-
salts, which are affected by light, are used in pho-

METALLURGY OF. Silver occurs most abundantly lowing ores: Native silver, Argentite, Pyrargyrite, and Cerargyrite. Besides these there are several with sulphur, arsenic, bromine, etc.; and it is also mall amount in the ores of other metals, notably in te. Pure silver is white, soft, very malleable, very e best known conductor of heat and electricity. Its 4° C.; it boils below the mpt. of platinum (1,775° C.), een distilled; its vapor is greenish. itted light. It crystallizes usually in octahedrons. Thin leaf is blue ted, it absorbs 22 times its volume of oxygen, which at suddenly when setting, producing a spitting. It xidize in dry or damp air, but is easily blackened be ntaining sulphu

The wet processes of silver extraction depend on the
fact that silver chloride, while not soluble in water, is solu-
iodide ore, it can be treated directly. If not, it is first roasted
ble in solutions of common salt, sodium hyposulphite, cop-
per hyposulphite, etc. If the ore is a chloride, bromide, or
roasting, whereby silver chloride is formed. The ore contain-
ing the silver as chloride is then placed in tanks having false
carefully with common salt, an operation called chloridizing
gustin's process), or sodium hyposulphite (Patera), or calcium
or perforated bottoms, and is washed with a strong brine (Au-
thiosulphate (Kiss), or hyposulphite of sodium and copper
(Russell). All these solutions dissolve notable quantities of
silver chloride, and are mostly precipitated by putting into
them strips of copper, which throws down pure silver. Rus-
sel's process can be applied to most silver ores without pre-
liminary chloridizing roasting, and he prefers to precipitate
cipitated silver sulphide is filtered
the silver as sulphide by adding sodium sulphide. The pre-

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