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Alloy. Homogeneous mixture of two or more metals. While possessing some of the characteristics of chemical compounds, they are not regarded as true chemical compounds, but rather as mechanical mixtures, though definite chemical compounds occur in some alloys.

All Saints' Day. Festival originated ab. 610, and kept in the R. C. and English Churches on Nov. 1

All Souls’ Day. Festival of the Church of Rome, begun ab. 950, and kept Nov. 2 as a day of prayer for the dead.

Allspice. Pimenta officinalis, small tree of the Myrtle family, extensively cultivated in the West Indies for its fruit, which is used for flavoring food.

Allspice, CAROLINA. Shrubs of the genus Buettneria or Calycanthus, natives of the southern Alleganies; also known as Strawberry Shrub or Sweet-scented Shrub.

Allspice, WILD. See BENJAMIN BUSH.

Allston, WASHINGTON, 1779–1843. American painter, poet, and novelist. Momaldi, 1842. In art he was West's pupil, and was supposed to resemble Titian.

Alluvium. Fine soil that has been deposited by the action of water. Alluvial soils are easily "worked and in general exceedingly fertile, though this depends somewhat upon the

source of the alluvium; i.e., the character of the soil whence it was obtained. They are usually unhealthy locations, malarial diseases, dysentery and diarrhoea being prevalent.

Allyl Alcohol. CH, CH.CH,OH. Bpt. 97°C. Hydrate of the allyl radical ; liquid of suffocating odor, present in crude wood spirit, and therefore formed by the destructive distillation of wood, usually prepared by the abstraction of water from glycerine.

Allyl Compounds. Containing the unsaturated group CH, CH.CH, in combination. They unite easily with bromine,

Allylene. CH : C.C.H. Unsaturated hydrocarbon belonging to the acetylene series.

Allyl isosulphocyanate. CH, CH.C.H.N.S : C. Called also allyl mustard oil; liquid boiling at 151°C.; prepared by distilling black mustard seed with water. It has the pungent and distinctive odor of mustard.

Alma. River in the Crimea; scene of a battle, Sept. 20, 1854, between the Russians, 46,000 strong, and the English, French and Turkish armies, 57,000. The Russians were routed with a loss of 5,000; the allies lost 3,400.

Almaden. Town of Spain, near the Sierra Morena, noted for its mines of quicksilver. These were worked of old by the Iberians and Romans, leased to the Fuggers of Augsburg ab. 1550, and to the Rothschilds 1843. Pop. ab. 9,000. The A. mines of Santa Clara Co., Cal., opened 1846, were named from those of Spain.

AImagest. Arabic translation of Ptolemy's Sumtaaris, ub. at Alexandria by Claudius Ptolemy, ab. 140. A colection of problems in geometry and astronomy, now noted as containing the earliest star catalogue. It was accepted for fourteen centuries as an undisputed authority on all astronomical matters.

Almagro, DIEGo D', 1475–1538. Conqueror, with Pizarro. of Peru in 1525, afterward Pizarro's enemy and victim. His son and namesake avenged him 1541, and was executed 1542.

AImanac. Book of tables published from year to year containing a calendar of days, weeks and months, a record of various astronomical phenomena, such as the times of rising and setting of the sun, moon, and other heavenly bodies, a

English Almanac, 17th Cent., Jan. to Mch.

register of ecclesiastical festivals and saints' days. In addition to these, a great variety of matter of a historical, statistical or astrological character is sometimes added.

AImandine, or ALMANDITE. (1) Variety of spinel. Variety of garnet.

Almansa. Town of s. e. Spain; scene of a decisive victory gained Apr. 25, 1707, by the French under, Berwick, over the allies of Charles III., who lost most of their infantry, with artillery and baggage. Nearly all Valencia and Aragon submitted to Philip V.

Alma-Tadema, LAURENZ, b. 1836. He was b. in Friesland, studied in Antwerp, and has lived in England since 1870. As a youth he conceived a passion for Egyptian and classic archaeology, and has devoted himself, as a painter almost exclusively to ancient subjects, in which field he has won worldwide reputation. His forte is painstaking minuteness of detail and fidelity to archaeologic memoranda. To these aims he has sacrificed vigor and breadth of effect. In .. of his rather cold and rigid methods of execution he has distinct greatness as a colorist, and in popularity and financial success is among the first modern painters. His most important work in America is Reading Homer, shown at the Columbian Exposition. Here were also seen, in the English Exhibit, his masterpieces, A Dedication to Bacchus and The Sculpture Gallery.

Almeida, FRANCEsco D', ab. 1455-1510. Portuguese viceroy of India 1505–8.

Almeida-Garrett, JoAo BAPTISTA D', 1799–1854. Portuguese poet and novelist; minister to Belgium 1834, ennobled 1852.

Almeria. Ancient Moorish city and seaport of Spain, on the gulf of Almeria, an arm of the Mediterranean. Pop., 1885, 38,378,

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Almery. Properly, a recess or cupboard in a wall, fur- no tendency to shed. It is only since 1840 that it has been nished with a door; also a movable piece of furniture; used in exported for manufacture in factories. See TYLOPA. Middle Ages and still in Italy to store the elements reserved for the Mass, and to contain the vestments of the clergy; often of stone, of considerable size and elaborately decorated.

Almohades. Dynasty of Mohammedan princes, who, from 1130, the year in which their founder died, to 1212, battle of Las Navas, ruled a vast empire, including at its height n. Africa from Tunis to the Atlantic, and Spain and Portugal as far as the Ebro and the Tagus; extinct in Spain 1257, in Africa 1269.

Almond. Prunus Amygdalus, small tree of the natural family Rosacece, native of w. Asia, and widely cultivated for

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Alpaca. Alpha Compounds. Those in which the substitution is in a hydrocarbon group next the group which gives character to the compound ; thus alphabrom propionic acid, CH.CHBr. COOH.

Alphabet. Any properly arranged list of the symbols its fruit: also in tropical America Goeffreua enerba a tree used by a given language for its simple sounds. Our English of the Pea family.

JUCIAN GREEK

LATIN WEBREW Almond Oil. Sp. gr. 0.913. It is expressed from sweet and bitter almonds, and consists of olein with some stearin and palmatin. Essential oil of bitter almonds is obtained by distilling with steam the almonds, ground up with cold water. It contains prussic acid and benzoic aldehyde.

Almoravides. Family of Mohammedan princes who ruled in Africa and Spain 1073–1147; their capital was Morocco, and their empire reached from the Ebro and Tagus to

0544ASS DDOD07 the frontiers of Soudan; overthrown by the Almohades.

Almquist, CARL JONAS LUDVIG, 1793–1866. Swedish dramatist, novelist, and poet.

Almucantar. Small circle of celestial sphere parallel to horizon. Also, name given by S. C. Chandler of Cambridge, Mass., to an instrument devised by him for observing the

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Italian writers of the 15th

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century.
Aloe. Genus of plants,

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Aloe, AMERICAN. See
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Alopecia. See BALD-

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v v vi vai VIII IX X with the Greeks and Armenians, and took the Byzantine emperor captive 1071.

Alpaca. Domesticated VICUNA (q.v.) kept in flocks on Alphabet is a modification of the Latin, as this of the Greek, elevated plains of Andes of Peru ; in color brown, gray, or which was based upon the Phænician. The letters doubtless black; its wool grows eight inches in length per year, with originated in hieroglyphics.

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Alpino, PROSPERO, 1553–1617. Italian botanist. tis Aegypti liber, 1592; De plantis eacoticis, 1627.

Alps. System of mountains of s. Europe, the highest, most extensive and complicated except the Caucasus. It sweeps around the northern end of Italy in a broad curve, occupying s. e. France, all Switzerland, Italy, and s. w. Austria, to the north frontier of Turkey. The system is often subdivided as follows: the region adjoining the boundary between France and Italy, extending from the Mediterranean n. to Mont Blanc and having a n. and s, trend is in three parts, known respectively, beginning at the sea, as the Maritime, Cottian, and Graian Alps. That part east of Mont Blanc, having an e. and w. trend, is separated into two groups of ranges, a northern and a southern. The first comprises the Bernese Alps, n. of the Rhone, the Alps of St. Gall, n. w. of the Rhine, the Noric, extending from Lake Constance to the Kahlenburg in w. Austria, and the Styrian, between the Noric and the Carnic. The latter comprise the Pennine Alps, between Mont Blanc and Monte Rosa, the Lepontine, extending from Monte Rosa to the sources of the Rhine; the Rhoetian, which extend to the sources of the Piave; and the Carnian, which form the frontier between Italy and Austria. The Dinaric Alps, which extend southeast down the east coast of the Adriatic, complete the system. The highest part is in Switzerland and adjacent regions of France and Italy. Here are found Mt. Blanc, the

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highest summit, 15,810 ft., Monte Rosa, 15,208 ft., and the Finster Aarhorn, 14,026 ft. Of the passes, Monte Cenis has an altitude of 6775 ft., the Simplon 6592 ft., the Splügen 6935 ft., Great St. Bernard 8150 ft., and St. Gothard 6976 ft. The mass of the Alps is composed of granite, gneiss, and other metamorphic rocks, with stratified beds upturned upon their flanks. The snow line is at an altitude of ab. 8900 ft., and glaciers descend to a level of 3400 ft. It is estimated that 1500 sq. miles are covered with snow and ice in these mountains. Alguifoux. PbS. Coarse-grained galenite, sometimes called potters' ore from its being used in glazing earthenware.

Alsace. Part of ancient Gaul, held by the Romans nearly 500 years; then by Franks and French monarchs till Otho I., when it became German, and by Austria 1273–1648, when much of it was ceded to France. Louis XIV. took forcible possession of nearly all the rest. It was held by France for two centuries, and reunited to Germany 1871, except a small district. Alsace-Lorraine. Province of the German empire, ceded by France 1871. Area, 5,668 sq. m. Pop., 1890, 1,603,506, of whom ab. one-eighth are of French origin. It sends 15 representatives to the Reichstag. More than three-fourths of the people are Catholics. Alsatia. Sanctuary for debtors and law-breakers in Whitefriars, London, till 1697; described in Scott's Fortunes of Nigel. Alsike. See CLOVER. Al-Sirat. Narrow bridge believed by Mohammedans to stretch across hell from earth to paradise. Altai Mountains. In Central Asia, between Siberia and n. w. China. Length ab. 1,000 m.; extreme ht., 12,790 ft. Altair, a AQUILAE. Star of first magnitude, Right ascension, 19h. 45m. 22s. Declination, 8° 34'32" n.

Altamaha. River of Georgia. It rises in the foot hills of the Blue Ridge and flows s. and s. e. Drainage area 14,109 sq. m., length 155 m.

Altar. Table on which, in primitive religions, sacrifices and libations were offered. In Greek and Roman, as well as in Jewish antiquity, it had an important part in the worship of the temple. Vitruvius gives rules for the position and construction of altars, which differ in magnitude and form according to the deities to whose service they are consecrated. In Christian

High Altar: Church of the Sacred Heart, Edinburgh.

worship, though the sacrifice became merely emblematic and typical, in Gothic architecture, the high altar became the central object of the church or cathedral, and was elaborately decorated.

Altar of Burnt-Offering. Among the Hebrews, the #. altar, placed before the Tabernacle, afterward before the emple, used for bloody sacrifices, and other oblations. In the Temple, entirely of brass, 20 cubits long, 10 high. Altar of Incense. Among the Hebrews, made of acaciawood, overlaid with gold, with four projecting horns, a cubit long and broad, and two cubits high. It stood in the Holy Place. Altazimuth. Astronomical instrument used to indicate ALTITUDE (q.v.) and AZIMUTH (q.v.) of any heavenly body. The most important altazimuth is at Greenwich. Altdorfer, ALBRECHT, 1488–1538. German painter, alderman and official architect at Ratisbon; a leader of the school dominated by Dürer. His Victory of Alexander the Great over Darius in Munich is one of his finest works.

Altenesch, BATTLE OF, 1234. Frisian Stedingers overpowered by 40,000 crusaders, instigated by Conrad of Marburg.

Alteratives. Group of medicines which are believed to alter condition of diseased tissues without their method of action being known. More exact methods of investigation have reduced their number. Mercury, iodine and its compounds, and arsenic, are the most prominent drugs included in this group.

Alternant. Determinant in which the elements of each row are functions of one variable and each column contains like functions of a different variable.

Alternate. In Botany, contradistinction to opposite; e.g., leaves placed singly at the nodes; and, generally, petals and sepals of flowers.

Alternate Angles. Plane, spherical or dihedral; formed by a transversal with two lines or planes on opposite sides of the transversal and of the two lines or planes involved.

Alternate Function. One which changes its sign when two of its elements are interchanged; name used by Cauchy for quantities now called “Determinants.”

Alternate Numbers. Formed by adding “n” numbers such that, the units of any two terms §o. multiplied, interchange of position of the factors changes the sign of the product. Like change of sign results with alternate numbers themselves.

Alternating Current. Succession of electric impulses in alternate directions. Such a current may be produced by the passage of a conductor to and fro through a positive or a negative magnetic field, or by the continuous motion of a conductor through magnetic fields of opposite polarities. In alternating dynamos the “frequency " may vary from twenty or thirty to many hundred in a second.

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Alternation. Change of order between the second and third terms of a proportion.

If A : B :: C

A. : C : : B

Also used, though rarely, for permutation.

Alternation of Generations. Mode of reproduction in which offspring differs from parent in mode of origin, or in form, or both, and in its turn the child produces offspring that resembles the grandparent; or the child may produce offspring like itself for several generations, but eventually the original form reappears. In the Hydroids the jellyfish first appears as buds on a plant-shaped colony of hydra-like zoöids; the egg of the jellyfish produces a hydra which, by budding again and again, restores the original stock with medusa-buds on it, that are in turn detached as separate animals that reproduce sexually by means of eggs. Such a typical case presents a series of non-sexual (asexual) generations, alternating with a sexual generation. In Plant-lice, we have a series of parthenogenetic summer-generations alternating with sexed generations that appear in the fall. See PARTHENOGENESIS, AMPHIGENESIS, METAGENESIS, HYPOGENESIS and STROPHOGENESIS.

Althaea. Genus of Mallow family. The so-called Shrubby Althaea is Hibiscus Syriacus, a tall shrub, native of western Asia, and much cultivated; known also as Rose of Jericho. The root of Marsh-mallow, Althaea officinalis, is used in medicine for

: D, by alternation : D.

A. rosea and A. officinalis.

its mucilaginous properties. . A favorite preparation in France is the Páte de Guimaure, a kind of lozenge made with mucilage of Althaea root, §. sugar and the white of egg. Althat rosea is the Hollyhock of the garden, and contains similar properties. Altitude. Angular distance of a star above horizon, measured on a vertical circle of the celestial sphere passing through the star. Alto. Strictly, the male voice of highest pitch in music; generally used as synonymous with contralto, the middle part in vocal harmony, sung by the low female voice. Also Italian name for the VIOLA (q.v.). Alton. City of Madison Co., Ill., on the Mississippi, 22 m. n. of St. Louis. Pop., 1890, 10,294. Altona. Largest city of Schleswig-Holstein, Germany; on m. bank of the Elbe, near Hamburg. Pop., 1890, 143,249. Altoona. City of Blair Co., Pa., at e. base of the Allegany plateau. It contains the principal offices and shops of the Pennsylvania Railroad. Pop., 1890, 30,337. Alto-rilievo. High relief or bold projection in sculpture. Altranstädt, PRUSSIA, TREATY OF. Between Sweden and Poland; signed Oct. 4, 1706. Another, 1714, between France and Germany. Altruism. Action or inclination prompted by the benevolent affections; desire of acting for the advantage of others, as opposed to egoism, desire of acting for our own advantage. Alula. See BASTARD WING. Alum. See ALUMS. Alum, BURNT. When alum is heated, it melts in its water of crystallization. If the heat be raised, the water passes off, and the resulting product, a white voluminous mass, is called “burnt alum.” Used in medicine. Alum-root. Popular name for Heuchera Americana, a N. American plant of the Saarifragaceae. Also, Geranium maculatum.

Alum shale. Clay containing pyrite and peat; used for making ALUM (q.v.).

Alumina. See ALUMINIUM TRIOXIDE. o

Aluminates. Class of compounds derived from aluminium hydroxide, Al(OH), by replacing, the hydrogen , by a metal. Thus, when sodium hydroxide is added to a solution of an aluminium salt, aluminium hydroxide is first precipitated, but is redissolved in an excess of sodium hydroxide. The compound in solution is thought to be sodium aluminate. §§. There are others of different composition, as AlO.OK; Ca(AlO4). The most important which occur in nature are the spinels.

Aluminium. Al. Sp. gr. 2.7. Mpt. 625°C., At, wt. 27. Discovered by Wöhler 1827. It is soluble in hydrochloric acid; it is not acted upon by nitric or sulphuric acids at ordinary temperatures; at higher temperatures action takes place and the corresponding salts are formed. It dissolves in solutions of caustic alkalies, forming aluminates. It acts both as an acid-forming and a base-forming element. It reduces many oxides when heated with them to a sufficiently high temperature; for this reason it is used in the preparation of boron and silicon. See ALUMINIUM, METALLURGY OF.

Aluminium Acetate. Al(C.H.O.),. in dyeing. It is usually made by o a solution of alum with a solution of lead acetate, when lead sulphate is precipitated, and potassium and aluminium acetates remain in solution. It may also be made by treating aluminium sulphate with lead acetate. It is sold under the name of “red liquor.”

Aluminium Bronze. Alloy of copper and aluminium, containing from 5 to 10 per cent of the latter. It resembles gold in color, is very hard and elastic. Ordinary reagents do not act upon it easily. It is used for cartridge-shells, unbarrels, gun-linings, helmets, hold-down bolts for mortar batteries, propellers, and small boats.

Aluminium Chloride. AlCl,. If aluminium hydroxide be treated with hydrochloric acid, aluminium chloride is formed, and crystallizes from the solution as AlCl,.6H,O. If the attempt be made to drive off the water of crystallization, the compound is decomposed, leaving alumina as a residue. To make anhydrous aluminium chloride, chlorine is passed over a heated mixture of the oxide and carbon. The chloride is volatile and is deposited in the cool part of the apparatus. When exposed to the air it attracts moisture. Aluminium chloride boils at 180° C. With sodium chloride and potassium chloride it forms double salts of the composition AlCl,.NaCl and AlCls. KCl.

Aluminium Fluoride. AlFls. Formed by the action of silicon fluoride upon aluminium. It forms cubic crystals which are insoluble in water and resist the action of acids. With sodium fluoride it forms a double compound. See CRYOLITE,

Aluminium Hydroxide. Al(OH),. It occurs as the mineral HYDRARGILLITE (q.v.). In the laboratory it is made by treating a solution of aluminium chloride with ammonia solution; formed in this way, it is a white, gelatinous precipitate, which loses water on being heated, forming meta-aluminic acid, AlO.OH. A compound of the same composition occurs in nature as the mineral DIASPORE (q.v.). If heated higher, aluminium trioxide, Al...O., is formed. In addition to these two hydroxides there is a third, Al,O(OH). The normal hydroxide is the starting point in the preparation of the other aluminium salts.

Aluminium, METALLURGY OF. Beauxite is the chief ore source of aluminium, and it occurs in France, in Austria, Ireland, Arkansas, Alabama and Georgia. It consists of aluminium oxide, water, iron oxide and silica, the last two as impurities. The market price varies from $6 to $10 aton for ore containing 60 to 80 per cent of alumina, corresponding to 30 to 45 per cent of aluminium. The 900 pounds of aluminium in a ton of $10 beauxite is worth about $500, when extracted, the great difference in the values of finished and raw material representing mainly the costly process of manufacture.

Aluminium compounds are very difficult to reduce to metal, resisting all the ordinary reducing agents. The German chemist Wöhler first obtained the metal as a powder in 1827, by decomposing the chloride by potassium; it resisted all attempts to melt it. The French savant Deville first produced it in large quantities, in 1855; his method being to reduce the double chloride of aluminium and sodium by sodium. The cost of production by this process was ab. $10 per pound, and it was used exclusively up to 1885. In 1886 electrical methods began to be operated on a commercial scale, and since 1890 have entirely supplanted the sodium process. The present method is as follows: Pure alumina is first prepared from beauxite, by roasting the fine ore mixed with soda ash in a furnace, washing out the combination of soda and alumina with water, and precipitating aluminium hydroxide from this solution by carbonic

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acid gas. The precipitate is filtered out, washed, dried and calcined, and is introduced into a molten bath of fused cryolite, fluorides of aluminium and sodium, which dissolves about 20 per cent of its weight of alumina. On passing an electric current through this bath only the dissolved alumina is decomposed, it being the weakest chemical compound present, while the fluorides constituting the solvent portion of the bath remain o The operation is carried on in a wroughtiron tank, 6 feet long, 3 feet wide and 2 feet deep, lined heavily with carbon. The fluid bath is 1 foot deep, and carbon cylinders dipping into it from above form the positive electrode, while the lining of the pot forms the negative pole. The distance of the carbon cylinders from the bottom is so regulated that the heat set free by the resistance to the passage of the current is sufficient to maintain the bath in fusion without the aid of external heat. When the alumina dissolved in the bath has been mostly decomposed, the current begins to attack the fluorides, forming the solvent, and sets free irritating fumes of carbon fluoride. To avoid this, the bath is kept well supplied with alumina. The metal accumulating at the bottom of the bath is periodically bailed out with ladles. The process is thus made continuous, a pot sometimes running several months without stopping. Each pot requires an electrical tension of 5 to 8 volts to operate it, and the output averages one pound of metal per lo, for every horse-power employed to generate the electricity. The purity of the metal depends mostly on the purity of the alumina used, for any iron oxide or silica in it would inevitably be reduced and pass into the metal as iron and silicon. Raw beauxite is sometimes employed instead of pure alumina, to produce a low grade suitable for some purposes. The cost of production, with not over 2 per cent of impurities, is between 30 and 40 cts. a pound. The largest works in the world are at the Falls of the Rhine, Switzerland, their annual output being over a million pounds. The only works in America are at New Kensington, Pa., on the Allegany River, 18 m. above Pittsburg; their yearly output is half a million unds. This firm is building a 6,000 horse-power plant at iagara Falls, which will have a yearly capacity of two million pounds, and will be in operation in 1895. The present annual production in the world is two million pounds, and will probably reach double that quantity in 1895. The color of aluminium is white with a shade of blue, especially in impure metal. Pure metal is about the same in softness and toughness as ". copper; under the knife-blade it cuts, smoothly. . A small proportion of impurity hardens it considerably and makes it cut gritty. In spécific gravity it is by far the lightest of the useful metals, being 2.6 to 2.7; the specific heat is high, 0.222, and the melting point is 625°C., a dull-red heat. The latent heat is the greatest of any known substance, being 100 calories according to quite recent experiments; in virtue of this quantity, it takes considerable time to melt even in a hot fire. In conducting power for heat and electricity, it stands next, after silver, copper and gold. In malleability it is but little inferior to gold and silver, the leaf having almost entirely displaced silver leaf; its ductility is likewise remarkable. In short, it stands in many physical properties intermediate between the noble and the so-called base metals. Pure aluminium is, like pure gold and pure silver, soft and not strong; but, like them, it may be orlon and strengthened by judicious alloying. . From 1 to 5 per cent of silver, copper, nickel, zinc, or titanium effects this improvement, rais. ing, the tensile strength 50 or 100 per cent, as the following table shows:

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These strong, light alloys replace the pure metal for purposes requiring hardness, strength and rigidity, such as portable instruments and vehicles of every description, etc. On account of its rapid conduction of heat, lightness and non-poisonous Properties, it is the best material known for culinary utensils. The use of these is increasing with great rapidity. Several hundred tons have been used in Germany for military equipments, such as ammunition cases, bayonet scabbards, shells, and drums. A few of the many other uses are surgical instruments, boats, pontoons, torpedo tubes, bicycles, watches, chains, horse-shoes, bitts, stirrups, pen-holders, match-boxes, etc.

The most important alloys in which it is the minor constituent are those with copper, iron and zinc. Copper containing up to 10 per cent of aluminium forms the aluminium bronzes,

which are fine-grained, tough, strong, and of a golden color, having the following mechanical properties:

Per cent of Color. Tensile strength Elongation Aluminium (lbs. per sq. in.) (per cent) 2% Reddish-gold. 35,000 35 5 18-carat gold. 50,000 30 744 Green gold. 55,000 25 10 Guinea gold. 80,000 15

Aluminium-brass is ordinary brass with 1 to 2 per cent of aluminium. It is 50 per cent stronger than ordinary brass, and can be forged hot like soft iron. In the steel industry aluminium has found important application as a de-oxidizing agent, being added in small quantities to molten steel just before casting. The effect is to produce ingots or castings free from blow-holes. When added to a bath of molten zinc, such as is used for galvanizing iron, it removes oxygen from the bath, prevents further oxidation of the zinc, and causes the zinc coating on the iron to be brighter and to keep its color better. Similar applications are made of its de-oxidizing powers in the metallurgy of iron and nickel.

Aluminium is sold in three grades: “extra" is over 99.5 per cent pure; ordinary “number one commercial" is guaranteed over 98 per cent pure; and “ commercial number two" is guaranteed over 95 pure and averages 96 per cent. This last quality is used in steel works; the first two are sold either in ingots for re-melting or in slabs for rolling. The prices, Feb. 1895, were 98 per cent 53 cts.; 94 per cent 50 cts. per pound.

Aluminium Nitrate. Al(NO,),. Made by dissolving aluminium hydroxide in nitric acid. It crystallizes in the form of Al(NO,),.9H,O, which fuses at 73°C. without decomposition; at 100°C. decomposition takes place. It is used in dyeing.

Aluminium Sodium Fluoride. See CRYOLITE.

Aluminium Sulphate. Al2(SO,),.18H2O. Made by dissolving aluminium hydroxide in dilute sulphuric acid and evaporating to crystallization, when a salt of this composition is i. If heated to redness, it is decomposed, leaving a residue consisting mainly of aluminium trioxide. It is soluble in 2 parts of water, has a sweetish, astringent taste and an acid reaction. It is manufactured in large quantities for use as a mordant and for sizing paper, etc.

Aluminium Trioxide, or ALUMINA. Al,O,. Made by heating the hydroxide. It occurs in nature in the form of ruby, sapphire, and corundum. It can be fused with the oxyhydrogen flame, and on melting it becomes crystalline. Artificial rubies and sapphires have been made in this way by adding the proper coloring matter to the fused alumina. It is insoluble in acids if it has been heated strongly. It can be obtained in a soluble form by fusing with acid potassium sulphate. Beauxite is an impure form.

Alums. Class of compounds of the type represented by common alum, potassium aluminium sulphate, KAl(SO.),12 H.O. Other alums may be regarded as derived from this by replacing the potassium with sodium, ammonium, rubidium, lithium, silver, caesium or thallium. Alums are also derived from the common form by substituting for the aluminium, iron, chromium or manganese. These all crystallize in octahedra modified by cubes, and are strictly isomorphous. They are all soluble in water and possess an astringent taste. The potassium and ammonium alums are used very extensively in dyeing. The former is employed in medicine as an astringent, as a styp

- tic, and as an application to unhealthy suppurating surfaces,

especially when deprived of its water of crystallization (burnt alum); it is also emetic in large doses, and is used to relieve the colic of lead poisoning. Added to bread it whitens it, rendering possible the use of inferior grades of flour, and increases its weight by absorbing appreciable amounts of moisture. Bread adulterated in this manner is unfit for use, as the alum soon disturbs the digestion and causes constipation. Alunite, or ALUMSTONE. K., Al,4SO,.6H2O. Natural hydrous sulphate of aluminium and potassium, found in Italy, Hungary, and other European countries. It is a product of the action of sulphurous vapors on the rocks with which the mineral is associated. It has been used as a source of alum, which is obtained from the mineral by repeated roastings and washings. It was first observed at Tolfa, near Rome. Alva, FERNANDo ALVAREz DE Toledo, DUKE OF, 1508–1583. Spanish general of Philip II.; governor of the Netherlands 1567– 73; detested for his cruelties. By his own account, he had ordered some 18,000 executions, chiefly for religious cause. He conquered Portugal 1580. Alvarado, ALONzo. Follower of Cortez in Mexico and of Pizarro in Peru ; captain-general there 1549–53. Alvarado, PEDRO DE, d. 1541. Officer of Cortez 1518; had command in city of Mexico 1520; gov. of Guatemala 1523, and also of Honduras 1535. Alvarez, FRANCISCO. Portuguese priest who was in Abyssinia 1515–21, and pub. an account of it 1540.

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