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# 1911 Encyclopædia Britannica/Pyrargyrite

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​PYRARGYRITE, a mineral consisting of silver sulphantimonite, Ag$_3$SbS$_3$, known also as dark red silver ore, an important source of the metal. It is closely allied to, and isomorphous with, the corresponding sulpharsenite known as proustite (q.v.) or light red silver ore. “Ruby silver” or red silver ore (German Rotgültigerz was mentioned by G. Agricola in 1546, but the two species so closely resemble one another that they were not completely distinguished until chemical analyses of both were made by J. L. Proust in 1804.
​Both crystallize in the ditrigonal pyramidal (hemimorphic-hemihedral) class of the rhombohedral system, possessing the same degree of symmetry as tourmaline. Crystals are perfectly developed and are usually prismatic in habit; they are frequently attached at one end, the hemimorphic character being then evident by the fact that the oblique striations on the prism faces are directed towards one end only of the crystal. Twinning according to several laws is not uncommon. The angles are nearly the same in the two species; the rhombohedral angle rr' being 71° 22' in pyrargyrite and 72° 12' in proustite. The hexagonal prisms of pyrargyrite are usually terminated by a low hexagonal pyramid (310) or by a drusy basal plane. The colour of pyrargyrite is usually greyish-black and the lustre metallic-adamantine; large crystals are opaque, but small ones and thin splinters are deep ruby-red by transmitted light, hence the name, from Gr. πῦρ (fire) and ἄργυρος (silver), given by E. F. Glocker in 1831. The streak is purplish-red, thus differing markedly from the scarlet streak of proustite and affording a ready means of distinguishing the two minerals. The hardness is 2½, and the specific gravity 5.85: the refractive indices and birefringence are very high, ω=3.084, ε=2.881. There is no very distinct cleavage and the fracture is conchoidal. The mineral occurs in metalliferous veins with calcite, argentiferous galena, native silver, native arsenic, &c. The best crystallized specimens are from St Andreasberg in the Harz, Freiberg in Saxony, and Guanajuato in Mexico. It is not uncommon in many silver mines in the United States, but rarely as distinct crystals; and it has been found in some Cornish mines.
Although the “ red silver ores ” afford a good example of isomorphism, they rarely form mixtures; pyrargyrite rarely contains as much as 3% of arsenic replacing antimony, and the same is true of antimony in proustite. Dimorphous with pyrargyrite and proustite respectively are the rare monoclinic species pyrostilpnite or fireblende (Ag$_3$SbS$_3$) and xanthoconite (Ag$_3$AsS$_3$): these four minerals thus form an isodimorphous group. (L. J. S.)
# 1911 Encyclopædia Britannica/Pyrene

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​PYRENE, C,6H10, a hydrocarbon found together with chrysene in the last portion of the coal tar distillate, and also in " Stupp " fat.
The crude solid product from the tar distillate is digested with carbon bi sulphide to dissolve the pyrene, the solution filtered and the solvent evaporated. The residue is dissolved in alcohol and to the cold saturated solution a cold alcoholic solution of picric acid is added. The picrate so formed is then decomposed by ammonia. On its separation from " Stupp " fat see E. Bamber er and M. Philip, Ann., 1887, 240, p. 161. It crystallizes in monochnic tables which melt at 148-149° C. Chromic acid oxidizes it to pyrene quinone, CNHBOZ, and pyrenic acid, Cu=, H18O¢. The picrate, which is easily soluble in benzene, crystallizes in long red needles melting at 222 When heated with hydriodic acid and phosphorus to 200° C. it yields a hexahydride. It has been obtained synthetically by M. Freund and H. Michaels (Ber., 1897, 30, p. 1383) by distilling thebenol over zinc dust in a stream of hydrogen, or by the action of hydriodic acid and phosphorus at 220° C. on thebenol
# 1911 Encyclopædia Britannica/Pyrazines, Piazines

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​PYRAZINES, PIAZINES, or PARADIAZINES, in organic chemistry, a group of compounds containing a ring system composed of 4 carbon atoms and 2 nitrogen atoms, the nitrogen atoms being in the para position; The di- and tri-methyl derivatives are found in the fusel oil obtained by fermentation of beetroot sugar (E. C. Morin, Comptes rendus, 1888, 106, p. 360). They were first prepared synthetically by reducing the isonitrosoketones. They may also be prepared by the inner condensation of a-aminoaldehydes or a-aminoketones in the
presence of a mild oxidizing agent, such as mercuric chloride or copper sulphate in boiling alkaline solution (L. Wolff, Bef., 1893, 26, p. 1830; S. Gabriel, ibid. p. 2207); and by the action of ammonia on a.-halogen ketonic compounds (W. Staedel and L. Rugheimer, Bef., 1876, 9, p. 563; V. Meyer and E. Braun, Bef., 1888, 21, p. 19). They are also formed when grape sugar is heated with ammonia or when glycerin is heated with ammonium chloride and ammonium phosphate (C. Stoehr, J ourn. pralzt. Chem., 1895 (2), 51, p. 450; 1896 (2), 54, p. 481). They are feeble basic compounds which distil unchanged. They are mostly soluble in water and somewhat hygroscopic in character. Their salts are easily dissociated. They form characteristic compounds with mercuric and auric chlorides. Their alkyl derivatives readily oxidize to pyrazine carboxylic acids. Pyrazine, C4H4N2, crystallizes from water in prisms, which have a heliotrope odour. It melts at 55° C. and boils at 115° C. It may also be obtained by elimination of carbon dioxide from the pyrazinc dicarboxylic acid formed when quinoxaline is oxidized with alkaline potassium permanganate (S. Gabriel). 2-5~-Dimethylpyrazfine, or ketine, C¢l°l2(CH3)2N2, is obtained by reducing isonitrosoacetone, or by heating glycerin with ammonium chloride and ammonium phosphate. It boils at 153° C.
Two classes of'dihydropyrazines are known, namely the I-4 and 2~3- dihydro-compounds, corresponding to the formulae II. and Ill., pyrazine being l. 1- '-HC-N'CH
HC~NH-CH HC-N~CH2 HzC-NH-CHz
(Pyrazine) ll (1-4 dihydro) Ill (2~3 dihydro) IV (Piperazine). Those of the former type are obtained by condensing a-bromketones with primar amines (A. T. Mason, fourn. Chem. Soc., 1893, 63, p. 1355); the flatter type result on condensing alkylene diamines with a.-dike tones. The 2-3 derivatives are somewhat unstable compounds, since on heating they readily give up two hydrogen atoms. Tetrahydropyrazines of the 1-2-3-4 type have also been obtained (L. Garzini, Bcr., 1891, 24, 956 R). Hexahydropyrazfine or piperazine (formula IV. above), also known as diethylene diamine, may be prepared by reducing pyrazine, or, better, by combining aniline and ethylene bromide to form diphenyl diethylene diamine, the dinitroso compound of which hydrolyses to para-dinitrosophenol and piperazine. It is a strong base, melting at 104° and boiling at 145°-146°. It is used in medicine on account of the high solubility of its salt with uric acid.
# 1911 Encyclopædia Britannica/Pyrethrum

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​PYRETHRUM. The pyrethrum or “feverfew” (nat. ord. Compositae), now regarded as a section of the genus Chrysanthemum, flowers in the early summer months, and is remarkable for its neat habit and the great variety of character and colour which it presents. The type form is the Caucasian species P. roseum of botanists, hardy perennial, with finely cut leaves and large flower heads, having a ray of deep rose-coloured ligulate florets surrounding the yellow centre or disk. They bloom during the months of May and June, as well as later, and are always most welcome ornaments for the flower borders, and useful for cutting for decorative purposes. There are now many excellent varieties, both single and double-flowered, in cultivation.
The pyrethrum grows best in soil of a loamy texture; this should be well manured and deeply trenched up before planting, and should be mulched in the spring by a surface dressing of half-decayed manure. The plants may be increased by division, the side shoots being taken off early in spring rather than in autumn, with a portion of roots attached. Plants disturbed in autumn frequently die during the winter. They may be placed either in separate beds or in the mixed flower border as may be required. In beds they can be supplemented as the season passes on by the intermixture of later blooming subjects, such as gladioli. Slugs are often destructive tpto the young shoots, but may be checked by a few sprinklings of soot or lime. Seeds should be sown in spring in a cold frame, and the young plants should be put out into beds when large enough, and should flower the following May. New varieties are being constantly introduced; the reader is referred to the catalogues of nurserymen for named kinds. The powdered root of P. roseum and other species is used in the manufacture of insect powders. P. parthenifolium var. aurem is the “golden-feather” of gardens, so much employed as an edging to flower-beds. P. parthenium, pellitory or “feverfew,” was formerly used in medicine. Its double-flowered form is well worth growing. P. uliginosum is the, “great ox-eye daisy” that flowers in September and October.
# 1911 Encyclopædia Britannica/Suessula

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​SUESSULA, an ancient town of Campania, Italy, in the plain 1½ m. W. of the modern Cancello, 9 m. S.E. of the ancient Capua. Its earlier history is obscure. In 338 B.C. it obtained Latin rights from Rome. In the Samnite and Hannibalic wars it was strategically important as commanding the entrance to the Caudine pass. Sulla seems to have founded a colony here. It is frequently named as an episcopal see up till the 10th century A.D., and was for a time the chief town of a small Lombard principality. It was several times plundered by the Saracens, and at last abandoned by the inhabitants in consequence of the malaria. The ruins of the town lie within the Bosco d'Acerra, a picturesque forest. They were more conspicuous in the 18th century than they now are, but traces of the theatre may still be seen, and débris of other buildings. Oscan tombs were excavated there between 1878 and 1886, and important finds of vases, bronzes, &c., have been made. The dead were generally buried within slabs of tufa arranged to form a kind of sarcophagus (see F. von Duhn in Römische Mitteilungen, 1887, p. 235 sqq.). Suessula lay on the line of the Via Popillia, which was here intersected by a road which ran from Neapolis through Acerrae, and on to the Via Appia, which it reached just west of the Caudine pass. On the hills above Cancello to the east of Suessula was situated the fortified camp of M. Claudius Marcellus, which covered Nola and served as a post of observation against Hannibal in Capua.  (T. As.)
# 1911 Encyclopædia Britannica/Suez

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​SUEZ, a port of Egypt on the Red Sea and southern terminus of the Suez Canal (q.v.), situated at the head of the Gulf of Suez in 29° 58′ 37″ N., 32° 31′ 18″ E. It is 80 m. E. by S. of Cairo in a direct line but 148 m. by rail, and is built on the north-west point of the gulf. Pop. (1907), 18,347. From the heights to the north, where there is a khedival chalet, there is a superb view to the south with the Jebel Ataka on the right, Mt Sinai on the left and the waters of the gulf between. Suez is supplied with water by the fresh-water canal, which starts from the Nile at Cairo and is terminated at Suez by a lock which, north of the town, joins it to the gulf. Before the opening of this canal in 1863 water had to be brought from “the Wells of Moses,” a small oasis 3 m. distant on the east side of the gulf. About 2 m. south of the town are the harbours and quays constructed on the western side of the Suez Canal at the point where the canal enters the gulf. The harbours are connected with the town by an embankment and railway built across a shallow, dry at low water save for a narrow channel. On one of the quays is a statue to Thomas Waghorn, the organizer of the “overland route” to India. The ground on which the port is built has all been reclaimed from the sea. The accommodation provided includes a dry dock 410 ft. long, 100 ft. broad and nearly 36 ft. deep. There are separate basins for warships and merchant ships, and in the road stead at the mouth of the canal is ample room for shipping. Suez is a quarantine station for pilgrims from Mecca; otherwise its importance is due almost entirely to the ships using the canal.
In the 7th century a town called Kolzum stood, on a site adjacent to that of Suez, at the southern end of the canal which then joined the Red Sea to the Nile. Kolzum retained some of the trade of Egypt with Arabia and countries farther east long after the canal was closed, but by the 13th century it was in ruins and Suez itself, which had supplanted it, was also, according to an Arab historian, in decay. On the Ottoman conquest of Egypt in the 16th century Suez became a naval as well as a trading station, and here fleets were equipped which for a time disputed the mastery of the Indian Ocean with the Portuguese. According to Niebuhr, in the 18th century a fleet of nearly twenty vessels sailed yearly from Suez to Jidda, the port of Mecca and the place of correspondence with India. When the French occupied Suez in 1798 it was a place of little importance, and the conflicts which followed its occupation in 1800 by an English fleet laid the greater part in ruins. The overland mail route from England to India by way of Suez was opened in 1837. The regular Peninsular & Oriental steamer service began a few years later, and in 1857 a railway was opened from Cairo through the desert. This line is now abandoned in favour of the railway which follows the canal from Suez to Ismailia, and then ascends the Wadi Tumilat to Zagazig, whence branches diverge to Cairo and Alexandria.
# 1911 Encyclopædia Britannica/Suet

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​SUET (M. Eng. sewet, a diminutive of O. Fr. seu, suis, mod. suif, lard, from Lat. sebum, or sevum, tallow, grease, probably allied to sapo, soap), the hard flaked white fat lying round the kidneys of the sheep or ox; that of the pig forms lard. Beef-suet is especially used in cookery.
# 1911 Encyclopædia Britannica/Malic Acid

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​MALIC ACID (Hydroxyethylene Succinic Acid), C$_4$H$_6$O$_5$, an organic acid found abundantly in the juices of many plants, particularly in mountain-ash berries, in unripe apples and in grapes. The acid potassium salt is also found in the leaves and stalks of rhubarb. Since the acid contains an asymmetric carbon atom, it can exist in three forms, a dextro-rotatory, a laevo-rotatory and an inactive form; the acid obtained in the various synthetical processes is the inactive form. It may be prepared by heating racemic acid (see Tartaric Acid) with fuming hydriodic acid; by heating fumaric acid (q.v.) with water at 150–200° C.; by the action of nitrous acid on inactive aspartic acid; and by the action of moist silver oxide on monobromsuccinic acid. It forms deliquescent crystals, which are readily soluble in alcohol and melt at 100° C. When heated for some time at 130° C. it yields fumaric acid (q.v.), and on rapid heating at 180° C. gives maleic anhydride and fumaric acid. It yields coumarins when warmed with sulphuric acid and phenols (H. v. Pechmann, Ber., 1884, 17, 929, 1649 et seq.). Potassium bichromate oxidizes it to malonic acid; nitric acid oxidizes it to oxalic acid; and hydriodic acid reduces it to succinic acid. The inactive variety may be split into the component active forms by means of its cinchonine salt (G. J. W. Bremer, Ber., 1880, 13, 352).
# 1911 Encyclopædia Britannica/Mallarmé, François René Auguste

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​MALLARMÉ, FRANÇOIS RENÉ AUGUSTE (1755–1835), French Revolutionist, the son of a lawyer, was born at Nancy on the 25th of February 1755. He was brought up in his father’s profession, and was appointed procureur-syndic of the district of Pont-à-Mousson. During the Revolution he was elected by the department of Meurthe deputy to the Legislative Assembly and the Convention, where he attached himself to the Mountain and voted for the death of Louis XVI. He was elected president of the Convention on the 30th of May 1793, and by his weakness during the crisis of the following day contributed much to the success of the insurrection against the Girondists. He took an active part in the levée-en-masse, and in November 1793 was given the task of establishing the revolutionary government in the departments of Meuse and Moselle, where he gained an unenviable notoriety by ordering the execution of the sentence of death decreed by the revolutionary tribunal on some young girls at Verdun who had offered flowers to the Prussians when they entered the town. After the fall of Robespierre he joined the group of “Thermidorians” and was sent on mission to the south of France, where he closed the Jacobin club at Toulouse and set free a number of imprisoned “suspects.” On the 1st of June 1795 he was denounced and arrested, but was soon set at liberty. In 1796 he was appointed by the Directory commissioner for the organization of the departments of Dyle and Mont-Tonnerre. Under the empire he was receiver of the droits réunis at Nancy, and lost his money in 1814 in raising a levy of volunteers. Appointed sub-prefect of Avesnes during the Hundred Days, he was imprisoned by the Prussians in revenge for the death of the maidens of Verdun, and lived in exile during the Restoration. He returned to France after the revolution of 1830, and died at Richemont (Seine-Inférieure) on the 25th of July 1835.
# 1911 Encyclopædia Britannica/Mallarmé, Stéphane

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​MALLARMÉ, STÉPHANE (1842–1898), French poet and theorist, was born at Paris, on the 18th of March 1842. His life was simple and without event. His small income as professor of English in a French college was sufficient for his needs, and, with his wife and daughter, he divided the year between a fourth-floor flat in Paris and a cottage on the banks of the Seine. His Tuesday evening receptions, which did so much to form the thought of the more interesting of the younger French men of letters, were almost as important a part of his career as the few carefully elaborated books which he produced at long intervals. L’Après-midi d’un faune (1876) and other fragments of his verse and prose had been known to a few people long before the publication of the Poésies complètes of 1887, in a facsimile of his clear and elegant handwriting, and of the Pages of 1891 and the Vers et prose of 1893. His remarkable translation of poems of Poe appeared in 1888, “The Raven” having been published as early as 1875, with illustrations by Manet. Divagations, his own final edition of his prose, was published in 1897, and a more or less complete edition of the Poésies, posthumously, in 1899. He died at Valvins, Fontainebleau, on the 9th of September 1898. All his life Mallarmé was in search of a new aesthetics, and his discoveries by the way were often admirable. But he was too critical ever to create freely, and too limited ever to create abundantly. His great achievement remains unfinished, and all that he left towards it is not of equal value. There are a few poems and a few pieces of imaginative prose which have the haunting quality of Gustave Moreau’s pictures, with the same jewelled magnificence, mysterious and yet definite. His later work became more and more obscure, as he seemed to himself to have abolished limit after limit which holds back speech from the expression of the absolute. Finally, he abandoned punctuation in verse, and invented a new punctuation, along with a new construction, for prose. Patience in the study of so difficult an author has its reward. No one in our time has vindicated with more pride the self-sufficiency of the artist in his struggle with the material world. To those who knew him only by his writings his conversation was startling in its clearness; it was always, like all his work, at the service of a few dignified and misunderstood ideas.
See also Paul Verlaine, Les Poètes maudits (1884); J. Lemaître, Les Contemporains (5th series, 1891); Albert Moekel, Stéphane Mallarmé, un héros (1899); E. W. Gosse, French Profiles (1905) and A. Symons, The Symbolist Movement in Literature (1900). A complete bibliography is given in the Poètes d’aujourd’hui (1880–1900, 11th ed., 1905) of MM. A. van Bever and P. Léautaud. (A. Sy.)
# 1911 Encyclopædia Britannica/Malleco

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​MALLECO, a province of southern Chile, once a part of the Indian territory of Araucania (q.v.), lying between the provinces of Bio-Bio on the N. and E., Cautin on the S. and Arauco on the W. Area, 2973 sq. m. Pop. (1895), 98,032. It belongs to the rainy, forested region of southern Chile, and is thinly populated, a considerable part of its population being Araucanian Indians, who occupy districts in the Andean foothills. Gold placer mining has attracted some attention, but the output is small. The principal industries are cattle and wheat raising and timber-cutting. The capital is Angol (pop., 7056 in 1895; estimated at 7638 in 1902), a small town in the northern part of the province, on the Malleco river, and a station on the Traiguen branch of the state railway. Traiguen (pop., 5732 in 1895; estimated at 7099 in 1902) in the southern part of the province is the second town in importance, and Victoria (pop., 6989 in 1895; estimated at 10,002 in 1902), about 20 m. E. of the last-named town, was for a time the terminal station of the main line of the railway.