Chapter XIV: Act 1861: s. 31, any person may arrest any one whom he shall find (1)

committing any offence relating to the coin, or other offence against that act.

A person arrested without warrant must not be detained in private custody but must be taken with all convenient speed to a police station or justice and there charged (Summary Jurisdiction Act 1879).

4. The arrest by hue and cry is where officers and private persons are concerned in _pursuing_ felons, or such as have dangerously wounded others. By the Fugitive Offenders Act 1881, provision was made for the arrest in the United Kingdom of persons committing treason, and felony in any of the British colonies and vice versa; as to the arrest of fugitives in foreign countries see EXTRADITION.

The remedy for a wrongful arrest is by an action for false imprisonment.

In Scotland the law of arrest in criminal procedure has a general constitutional analogy with that of England, though the practice differs with the varying character of the judicatories. Colloquially the word arrest is used in compulsory procedure for the recovery of debt; but the technical term applicable in that department is _caption_, and the law on the subject is generically different from that of England. There never was a practice in Scottish law corresponding with the English arrest in mesne process; but by old custom a warrant for caption could be obtained where a creditor made oath that he had reason to believe his debtor meditated flight from the country, and the writ so issued is called a warrant against a person _in meditatione fugae_. Imprisonment of old followed on ecclesiastical cursing, and by fiction of law in later times it was not the creditor's remedy, but the punishment of a refractory person denounced rebel for disobedience to the injunctions of the law requiring fulfilment of his obligation. The system was reformed and stripped of its cumbrous fictions by an act of the year 1837. Although the proceedings against the person could only follow on completed process, yet, by a peculiarity of the Scottish law, documents executed with certain formalities, and by special statute bills and promissory notes, can be registered in the records of a court for execution against the person as if they were judgments of the court.

The general principles as to the law of arrest in most European countries correspond more or less exactly to those prevailing in England.

An _arrest of a ship_, which is the method of enforcing the admiralty process _in rem_, founded either on a maritime lien or on a claim against the ship, is dealt with under ADMIRALTY JURISDICTION.

See also article ATTACHMENT.

_Arrest of Judgment_ is the assigning just reason why judgment should not pass, notwithstanding verdict given, either in civil or in criminal cases, and from intrinsic causes arising on the face of the record.

_United States._--The law of arrest assimilates to that existing in England. Actual manual touching is not necessary (_Pike_ v. _Hanson_, 9 N.H. 491; _Hill_ v. _Taylor_, 50 Mich. 549); words of arrest by the officer, not protested against and no resistance offered, are sufficient (_Emery_ v. _Chesley_, 18 N.H. 198; _Goodell_ v. _Tower_, 1904, 58 Am. Rep. 790). Words of arrest, staying over night at prisoner's house, going with him before the magistrate next day constitute arrest (_Courtery_ v. _Dozier_, 20 Ga. 369). Restraining a person in his own house is arrest.

In civil cases in most of the states arrest for debt is abolished, except in cases of fraud or wilful injury to persons or property by constitutional provision or by statute. One arrested under process of a federal court cannot be arrested under that of a state court for the same cause. There is no provision in the United States constitution as to imprisonment for debt, but congress has enacted (in Rev. Stat., s. 990) that all the provisions of the law of any state applicable to such imprisonment shall apply to the process of federal courts in that state. A woman can be arrested in New York for wilful injury to person, character or property, and in certain other cases (Code, s. 553). The president, federal officials, governors of states, members of congress and of state legislatures (during the session), marines, soldiers and sailors on duty, voters while going to and from the polls, judges, court officials (1904, 100 N.W. 591), coroners and jurors while attending upon their public duties, lawyers, parties and witnesses while going to, attending or returning from court, and generally married women without separate property, are exempt from arrest.

In criminal cases a bench-warrant in New York may be served in any county without being backed by a magistrate (Code Crim. Proc., s. 304). In Nebraska one found violating the law may be arrested and detained until a legal warrant can be issued (Crim. Code, s. 283). A bail may lawfully recapture his principal (1905) 121 Georgia Rep. 594. Foreign ambassadors and ministers and their servants are exempt from arrest. Exemption from arrest is a privilege, not of the court, as in England, but of the person, and can be waived (_Petrie_ v. _Fitzgerald_, 1 Daly 401).

ARRESTMENT, in Scots law, the process by which a creditor detains the goods or effects of his debtor in the hands of third parties till the debt due to him shall be paid. It is divided into two kinds: (1) Arrestment in security, used when proceedings are commencing, or in other circumstances where a claim may become, but is not yet, enforceable; and (2) Arrestment in execution, following on the decree of a court, or on a registered document, under a clause or statutory power of registration, according to the custom of Scotland. By the process of arrestment the property covered is merely retained in place; to realize it for the satisfaction of the creditor's claim a further proceeding called "furthcoming" is necessary. By old practice, alimentary funds, i.e. those necessary for subsistence, were not liable to arrestment. By the Wages Arrestment Limitation (Scotland) Act 1870, the wages of all labourers, farm-servants, manufacturers, artificers and work-people are not arrestable except (1) in so far as they exceed 20s. per week; but the expense of the arrestment is not to be charged against the debtor unless the sum recovered exceed the amount of the said expense; or (2) under decrees for alimentary allowances and payments, or for rates and taxes imposed by law.

ARRETIUM (mod. _Arezzo_), an ancient city of Etruria, in the upper valley of the Arno, situated on the Via Cassia, 50 m. S.E. of Florentia. The site of the original city is not quite certain; some writers place it on the isolated hill called Poggio di S. Cornelio, 2-1/2 m. to the S.E., where remains of a fortified _enceinte_ still exist (cf. F. Noack in _Romische Mitteilungen_, 1897, p. 186); while others maintain, and probably rightly, that it occupied the hill at the summit of the modern town, where the medieval citadel (_fortezza_) was erected, and which was enclosed by an ancient wall. Numerous Etruscan tombs have been discovered within the lower portion of the area of the modern town, which appears to correspond in site with the Roman (_C.I.L._ xi. p. 1082; G. Gamurrini in _Notizie degli scavi_, 1883, 262; 1887, 437). Vitruvius (ii. 8. 9) and Pliny (_Nat. Hist._ xxxv. 173) speak of the strength of its walls of bricks, but these have naturally disappeared. Many remains of Roman buildings have been discovered within the modern town, and the amphitheatre is still visible in the southern angle. Arretium appears as one of the cities which aided the Tarquins after their expulsion. It was an opponent of Rome at the end of the 4th and beginning of the 3rd century B.C., but soon sought for help against the attacks of the Gauls, against whom it was almost a frontier fortress. It was an important Roman base during the Hannibalic wars (though at one time it threatened defection--Livy xxvii. 21-24), and in 205 B.C. was able to furnish Scipio with a considerable quantity of arms and provisions (Livy xxviii. 45). In 187 B.C. the high road was extended as far as Bononia. Arretium took the part of Marius against Sulla, and the latter settled some of his veterans there as colonists. Caesar, or Octavian, added others, so that there are three classes, _Arretini veteres, Fidentiores_, and _Iulienses_. A considerable contingent from Arretium joined Catiline and in 49 B.C. Caesar occupied it. C. Maecenas[1] was perhaps a native of Arretium. Its fertility was famous in ancient times, and still more the red pottery made of the local clay, with its imitation of chased silver. The reliefs upon it are sometimes of considerable beauty, and large quantities of it, and the sites of several of the kilns, have been discovered in and near Arretium. It was also considerably exported. See _Corp. Inscrip. Lat._ xi. (Berlin, 1901) p. 1081, and _Notizie degli scavi, passim_ (especially, 1884, 369, for the discovery of a fine group of the moulds from which these vases were made). The museum contains a very fine collection of these and a good collection of medieval majolica. (T. As.)

FOOTNOTE:

[1] The name Cilnius was apparently never borne by Maecenas himself,
though he is so described, e.g. by Tacitus, _Ann_. vi. II, cf.
Macrob. ii. 4, 12. The Cilnii with whom Maecenas was connected were a
noble Etruscan family.

ARRHENIUS, SVANTE AUGUST (1859- ), Swedish physicist and chemist, was born on the 19th of February 1859, at Schloss Wijk, near Upsala. He studied at Upsala from 1876 to 1881 and at Stockholm from 1881 to 1884, then returning to Upsala as privat-docent in physical chemistry. He spent two years from 1886 to 1888 in travelling, and visited Riga Polytechnic and the universities of Wurzburg, Graz, Amsterdam and Leipzig. In 1891 he was appointed lecturer in physics at Stockholm and four years later became full professor. Arrhenius is specially associated with the development of the theory of electrolytic dissociation, and his great paper on the subject, _Recherches sur la conductibilite galvanique des electrolytes_--(1) _conductibilite galvanique des solutions aqueuses extremement diluees_, (2) _theorie chimique des electrolytes_, was presented to the Stockholm Academy of Sciences in 1883. He was subsequently continuously engaged in extending the applications of the doctrine of electrolytic conduction in relation not only to the problems of chemical action but also, on the supposition that in certain conditions the air conducts electrolytically, to the phenomena of atmospheric electricity. In 1900 he published a _Larobok i teoretik elektrokemi_, which was translated into German and English, and his _Lehrbuch der kosmischen Physik_ appeared in 1903. In 1904 he delivered at the university of California a course of lectures, the object of which was to illustrate the application of the methods of physical chemistry to the study of the theory of toxins and antitoxins, and which were published in 1907 under the title _Immunochemistry_. In his _Worlds in the Making_ (1908), an English translation of _Das Werden der Welten_ (1907), he combated the generally accepted doctrine that the universe is tending to what Clausius termed _Warmetod_ through exhaustion of all sources of heat and motion, and suggested that by virtue of a mechanism which maintains its available energy it is self-renovating, energy being "degraded" in bodies which are in the solar state, but "elevated" or raised to a higher level in bodies which are in the nebular state. He further put forward the conception that life is universally diffused, constantly emitted from all habitable worlds in the form of spores which traverse space for years or ages, the majority being ultimately destroyed by the heat of some blazing star, but some few finding a resting-place on bodies which have reached the habitable stage.

ARRIA, in Roman history, the heroic wife of Caecina Paetus. When her husband was implicated in the conspiracy of Scribonianus against the emperor Claudius (A.D. 42), and condemned to death, she resolved not to survive him. She accordingly stabbed herself with a dagger, which she then handed to him with the words, "Paetus, it does not hurt" (_Paete, non dolet_; see Pliny, _Epp._ iii. 16; Martial i. 14; Dio Cassius lx. 16). Her daughter, also called Arria, was the wife of Thrasea Paetus. When he was condemned to death by Nero, she would have imitated her mother's example, but was dissuaded by her husband, who entreated her to live for the sake of their children. She was sent into banishment (Tacitus, _Annals_, xvi. 34).

ARRIAN (FLAVIUS ARRIANUS), of Nicomedia in Bithynia, Greek historian and philosopher, was born about A.D. 96, and lived during the reigns of Hadrian, Antoninus Pius and Marcus Aurelius. In recognition of his abilities, he received the citizenship of both Athens and Rome. He was greatly esteemed by Hadrian, who appointed him governor (_legatus_) of Cappadocia (131-137), in which capacity he distinguished himself in a campaign against the Alani. This is the only instance before the 3rd century in which a first-rate Roman military command was given to a Greek. Arrian spent a considerable portion of his time at Athens, where he was archon 147-148. With his retirement or recall from Cappadocia his official career came to an end. In his declining years, he retired to his native place, where he devoted himself to literary work. He died about 180. His biography, by Dio Cassius, is lost.

When young, Arrian was the pupil and friend of Epictetus, who had probably withdrawn to Nicopolis, when Domitian expelled all philosophers from Rome. He took verbatim notes of his teacher's lectures, which he subsequently published under the title of _The Dissertations_ ([Greek: Diatribai]), in eight books, of which the first four are extant and constitute the chief authority for Stoic ethics, and _The Encheiridion_ (i.e. Manual) _of Epictetus_, a handbook of moral philosophy, for many years a favourite instruction book with both Christians and pagans. It was adapted for Christian use by St Nilus of Constantinople (5th century), and Simplicius (about 550) wrote a commentary on it which we still possess.

The most important of Arrian's original works is his _Anabasis of Alexander_, in seven books, containing the history of Alexander the Great from his accession to his death. Arrian's chief authorities were, as he tells us, Aristobulus of Cassandreia and Ptolemy, son of Lagus (afterwards king of Egypt), who both accompanied Alexander on his campaigns. In spite of a too indulgent view of his hero's defects, and some over-credulity, Arrian's is the most complete and trustworthy account of Alexander that we possess.

Other extant works of Arrian are: _Indica_, a description of India in the Ionic dialect, including the voyage of Nearchus, intended as a supplement to the _Anabasis; Acies Contra Alanos_, a fragment of importance for the knowledge of Roman military affairs; _Periplus of the Euxine_, an official account written (131) for the emperor Hadrian; _Tactica_, attributed by some to Aelianus, who wrote in the reign of Trajan; _Cynegeticus_, a treatise on the chase, supplementing Xenophon's work on the same subject; the _Periplus of the Erythraean Sea_, attributed to him, is by a later compiler. Amongst his lost works may be mentioned: [Greek: Ta mer Alexandron], a history of the period succeeding Alexander, of which an epitome is preserved in Photius; histories of Bithynia, the Alani and the Parthian wars under Trajan; the lives of Timoleon of Syracuse, Dion of Syracuse and a famous brigand named Timoleon. Arrian's style is simple, lucid and manly; but his language, though pure, presents some peculiarities. He was called "Xenophon the younger" from his imitation of that writer, and he even speaks of himself as Xenophon.

Complete works ed. F. Dubner (1846); _Anabasis_, C. Abicht (1889);
with notes, C.W. Kniger (1835), C. Sintenis (1867) C. Abicht (1875);
_Scripta Minora_, R. Hercher and A. Eberhard (1885), A.J. Roos, i.,
containing the _Anabasis_ (Teubner series, 1907). English translations
_Anabasis_, Rooke (1812), _Anabasis_ and _Indica_, E.J. Chinnock
(1893); _Voyage of Nearchus_ with the spurious _Periplus_, W. Vincent
(1807), J.W. M'Crindle (Calcutta, 1879), _Periplus of the Euxine_, W.
Falconer (1805), Cynegettcus [W. Dansey] (1831). See also E. Bolla,
_Arriano di Nicomedia_ (1890); E. Schwartz in Pauly-Wissowa's
_Realencyclopadie der classischen Altertumswissenschaft_ (1896), H.F.
Pelham, "Arrian as Legate of Cappadocia," in _English Historical
Review_, October 1896; article GREECE: _History, ancient_,
"Authorities."

ARRIS (Fr. _areste_, or _arete_), in architecture, the sharp edge or angle in which two sides or surfaces meet.

ARRONDISSEMENT (from _arrondir_, to make round), an administrative subdivision of a department in France. Dating nominally from 1800, the arrondissement was really a re-creation of the "district" of 1790. It comprises within itself the canton and the commune. It differs from the department and from the commune in being merely an administrative division and not a complete legal personality with power to acquire and possess. The purposes for which it exists are, again, unlike those of the department and the commune, comparatively limited. It is the electoral district for the chamber of deputies, each arrondissement returning one member; if the population is in excess of 100,000 it is divided into two or more constituencies. It is also a judicial district having a court of first instance. It is under the control of a sub-prefect. There are 362 arrondissements in the 87 departments. Each arrondissement has a council, with as many members as there are cantons, whose function is to subdivide among the communes their _quota_ of the direct taxes charged to the arrondissement by the general council of the department. (See FRANCE) Somewhat different from the arrondissements of the department are the arrondissements (20 in number) into which Paris is divided. They bear a certain resemblance to the sub-municipalities created in London by the London Government Act 1899, and each forms a local administrative unit (see PARIS).

France is also subdivided, for purposes of defence, into five _maritime_ divisions, termed arrondissements. Instituted originally under the Consulate, they were suppressed in 1815, but re-established again in 1826. They are under the direction of maritime prefects, who, by a decree of 1875, must be vice-admirals in the navy.

ARROWROOT. A large proportion of the edible starches obtained from the rhizomes or root-stocks of various plants are known in commerce under the name of arrowroot. Properly the name should be restricted to the starch yielded by two or three species of _Maranta_ (nat. ord. Marantaceae), the chief of which is _M. arundinacea_; and when genuine or West Indian arrowroot is spoken of, it is understood that this is the variety meant. _Maranta arundinacea_ is probably a native of Guiana and western Brazil, but it has long been cultivated in the West Indian Islands, and has now spread to most tropical countries. The plant is a herbaceous perennial with a creeping root-stock which gives off fleshy cylindrical branches or tubers, covered with pale brown or white scales and afterwards ringed with their scars. It is at the period when these tubers are gorged with starch, immediately before the season of rest, that it is ripe for use. In addition to about 25% of starch, the tubers contain a proportion of woody tissue, vegetable albumen and various salts. The arrowroot may be separated on a small scale in the same manner as potato-starch is frequently prepared, that is, by peeling the root and grating it in water, when the starch falls to the bottom. The liquor is then drained off, and the starch purified by repeated washings till it is ready for drying. On a large scale the manufacture of arrowroot is conducted with specially arranged machinery. The rhizomes when dug up are washed free of earthy impurities and afterwards skinned. Subsequently, according to Pereira's _Materia Medica_, "the carefully skinned tubers are washed, then ground in a mill, and the pulp washed in tinned-copper cylindrical washing-machines. The fecula (dim. of Lat. _faex_, dregs, or sediment) is subsequently dried in drying-houses. In order to obtain the fecula free from impurity, pure water must be used, and great care and attention paid in every step of the process. The skinning or peeling of the tubers must be performed with great nicety, as the cuticle contains a resinous matter which imparts colour and a disagreeable flavour to the starch. German-silver palettes are used for skinning the deposited fecula, and shovels of the same metal for packing the dried fecula. The drying is effected in pans, covered with white gauze to exclude dust and insects."

Arrowroot Plant (Maranta arundinacea).--Fig. 1, stem, leaves and flowers; fig. 2, tubers.]

Arrowroot is distinguished by the granules agglomerating into small balls, by slightly crepitating when rubbed between the fingers, and by yielding with boiling water a fine, transparent, inodorous and pleasant-tasting jelly. In microscopic structure the granules present an ovoid form, marked with concentric lines very similar to potato-starch, but readily distinguished by having a "hilum" marking at the thick extremity of the granule, while in potato-starch the same appearance occurs at the thin end (compare figs. 3 and 4 below). In addition to the West Indian supplies, arrowroot is found in the commerce of Brazil, the East Indies, Australia, Cape Colony and Natal.

Fig. 3. Potato.
Fig. 4. Arrowroot.
Fig. 5. Tous-les-mois.
Fig. 6. Manihot.]

The name "arrowroot" is derived from the use by the Mexican Indians of the juice of the fresh root as an application to wounds produced by poisoned arrows. Sir Hans Sloane refers to it in his _Catalogue of Jamaica Plants_ (1696), and it is said to have been introduced into England by William Houston about 1732. It is grown as a stove-plant in botanic gardens. The slender, much-branched stem is 5 or 6 ft. high, and bears numerous leaves with long, narrow sheaths and large spreading ovate blades, and a few short-stalked white flowers.

_Tous-les-mois_, or Tulema arrowroot, also from the West Indies, is obtained from several species of _Canna_, a genus allied to _Maranta_, and cultivated in the same manner. The granules of _tous-les-mois_ are readily distinguishable by their very large size (fig. 5). East Indian arrowroot is obtained from the root-stocks of several species of the genus _Curcuma_ (nat. ord. Zingiberaceae), chiefly _C. angustifolia_, a native of central India. Brazilian arrowroot is the starch of the cassava plant, a species of Manihot (fig. 6), which when agglutinated on hot plates forms the tapioca of commerce. The cassava is cultivated in the East Indian Archipelago as well as in South America. _Tocca_, or _Otaheite_ arrowroot, is the produce of _Tacca pinnatifida_, the pia plant of the South Sea Islands. Portland arrowroot was formerly prepared on the Isle of Portland from the tubers of the common cuckoo-pint, _Arum maculatum_. Various other species of arum yield valuable food-starches in hot countries. Under the name of British arrowroot the farina of potatoes is sometimes sold, and the French excel in the preparation of imitations of the more costly starches from this source. The chief use, however, of potato-farina as an edible starch is for adulterating other and more costly preparations. This falsification can readily be detected by microscopic examination, and the accompanying drawings exhibit the appearance under the microscope of the principal starches we have described. Although these starches agree in chemical composition, their value as articles of diet varies considerably, owing to different degrees of digestibility and pleasantness of taste. Arrowroot contains about 82% of starch, and about 1% of proteid and mineral matter. Farina, or British arrowroot, at about one-twelfth the price, is just as useful and pleasant a food.

ARROWSMITH, the name of an English family of geographers. The first of them, Aaron Arrowsmith (1750-1823), migrated to London from Winston in Durham when about twenty years of age, and was employed by John Gary, the engraver. In 1790 he made himself famous by his large chart of the world on Mercator's projection. Four years later he published another large map of the world on the globular projection, with a companion volume of explanation. The maps of North America (1796) and Scotland (1807) are the most celebrated of his many later productions. He left two sons, Aaron and Samuel, the elder of whom was the compiler of the _Eton Comparative Atlas_, of a Biblical atlas, and of various manuals of geography. They carried on the business in company with John Arrowsmith (1790-1873), nephew of the elder Aaron. In 1834 John published his _London Atlas_, the best set of maps then in existence. He followed up the atlas with a long series of elaborate and carefully executed maps, those of Australia, America, Africa and India being especially valuable. In 1863 he received the gold medal of the Royal Geographical Society, of which body he was one of the founders.

ARROYO (O. Sp. _arrogio_, Lat. _arrogium_, a rivulet or stream), the channel of a stream cut in loose earth, found often at the head of a gully, where the water flows only at certain seasons of the year.

ARSACES, a Persian name, which occurs on a Persian seal, where it is written in cuneiform characters. The most famous Arsaces was the chief of the Parni, one of the nomadic Scythian or Dahan tribes in the desert east of the Caspian Sea. A later tradition, preserved by Arrian, derives Arsaces I. and Tiridates from the Achaemenian king Artaxerxes II., but this has evidently no historical value. Arsaces, seeking refuge before the Bactrian king Diodotes, invaded Parthia, then a province of the Seleucid empire, about 250 B.C. (Strabo xi. p. 515, cf. Arrian p. 1, Muller, in Photius, _Cod._ 58, and Syncellus p. 284). After two years (according to Arrian) he was killed, and his brother Tiridates, who succeeded him and maintained himself for a short time in Parthia, during the dissolution of the Seleucid empire by the attacks of Ptolemy III. (247 ff.), was defeated and expelled by Seleucus II. (about 238). But when this king was forced, by the rebellion of his brother, Antiochus Hierax, to return to the west, Tiridates came back and defeated the Macedonians (Strabo xi. pp. 513, 515; Justin xli. 4; Appian, _Syr._ 65; Isidorus of Charax 11). He was the real founder of the Parthian empire, which was of very limited extent until the final decay of the Seleucid empire, occasioned by the Roman intrigues after the death of Antiochus IV. Epiphanes (165 B.C.), enabled Mithradates I. and his successors to conquer Media and Babylonia. Tiridates adopted the name of his brother Arsaces, and after him all the other Parthian kings (who by the historians are generally called by their proper names), amounting to the number of about thirty, officially wear only the name Arsaces. With very few exceptions only the name [Greek: ARSAKIS] (with various epithets) occurs on the coins of the Parthian kings, and the obverse generally shows the seated figure of the founder of the dynasty, holding in his hand a strung bow. The Arsacidian empire was overthrown in A.D. 226 by Ardashir (Artaxerxes), the founder of the Sassanid empire, whose conquests began about A.D. 212. The name Arsaces of Persia is also borne by some kings of Armenia, who were of Parthian origin. (See PERSIA and PARTHIA.) (Ed. M.)

ARS-AN-DER-MOSEL, a town of Germany, in the imperial province Alsace-Lorraine, 5 m. S. of Metz on the railway to Noveant. It has a handsome Roman Catholic church and extensive foundries. In the vicinity are the remains of a Roman aqueduct, which formerly spanned the valley. Pop. 5000.

ARSCHOT, PHILIPPE DE CROY, DUKE OF (1526-1595), governor-general of Flanders, was born at Valenciennes, and inherited the estates of the ancient and wealthy family of Croy. Becoming a soldier, he was made a knight of the order of the Golden Fleece by Philip II., king of Spain, and was afterwards employed in diplomatic work. He took part in the troubles in the Netherlands, and in 1563 refused to join William the Silent and others in their efforts to remove Cardinal Granvella from his post. This attitude, together with Arschot's devotion to the Roman Catholic Church, which he expressed by showing his delight at the massacre of St Bartholomew, led Philip of Spain to regard him with still greater favour, which, however, was withdrawn in consequence of Arschot's ambiguous conduct when welcoming the new governor, Don John of Austria, to the Netherlands in 1576. In spite, however, of his being generally distrusted by the inhabitants of the Netherlands, he was appointed governor of the citadel of Antwerp when the Spanish troops withdrew in 1577. After a period of vacillation he deserted Don John towards the end of that year. Jealous of the prince of Orange, he was then the head of the party which induced the archduke Matthias (afterwards emperor) to undertake the sovereignty of the Netherlands, and soon afterwards was appointed governor of Flanders by the state council. A strong party, including the burghers of Ghent, distrusted the new governor; and Arschot, who was taken prisoner during a riot at Ghent, was only released on promising to resign his office. He then sought to regain the favour of Philip of Spain, and having been pardoned by the king in 1580 again shared in the government of the Netherlands; but he refused to serve under the count of Fuentes when he became governor-general in 1594, and retired to Venice, where he died on the 11th of December 1595.

See J.L. Motley, _The Rise of the Dutch Republic_.

ARSENAL, an establishment for the construction, repair, receipt, storage and issue of warlike stores; details as to _materiel_ will be found under AMMUNITION, ORDNANCE, &c. The word "arsenal" appears in various forms in Romanic languages (from which it has been adopted into Teutonic), i.e. Italian _arzanale_, Spanish _arsenal_, &c.; Italian also has _arzana_ and _darsena_, and Spanish a longer form _atarazanal_. The word is of Arabic origin, being a corruption of _daras-sina'ah_, house of trade or manufacture, _dar_, house, _al_, the, and _sina'ah_, trade, manufacture, _sana'a_, to make. Such guesses as _arx navalis_, naval citadel, _arx senatus_ (i.e. of Venice, &c.), are now entirely rejected.

A first-class arsenal, which can renew the _materiel_ and equipment of a large army, embraces a gun factory, carriage factory, laboratory and small-arms ammunition factory, small-arms factory, harness, saddlery and tent factories, and a powder factory; in addition it must possess great store-houses. In a second-class arsenal the factories would be replaced by workshops. The situation of an arsenal should be governed by strategical considerations. If of the first class, it should be situated at the base of operations and supply, secure from attack, not too near a frontier, and placed so as to draw in readily the resources of the country. The importance of a large arsenal is such that its defences would be on the scale of those of a large fortress. The usual subdivision of branches in a great arsenal is into A, Storekeeping; B, Construction; C, Administration. Under A we should have the following departments and stores:--Departments of issue and receipt, pattern room, armoury department, ordnance or park, harness, saddlery and accoutrements, camp equipment, tools and instruments, engineer store, magazines, raw material store, timber yard, breaking-up store, unserviceable store. Under B--Gun factory, carriage factory, laboratory, small-arms factory, harness and tent factory, powder factory, &c. In a second-class arsenal there would be workshops instead of these factories. C--Under the head of administration would be classed the chief director of the arsenal, officials military and civil, non-commissioned officers and military artificers, civilian foremen, workmen and labourers, with the clerks and writers necessary for the office work of the establishments. In the manufacturing branches are required skill, and efficient and economical work, both executive and administrative; in the storekeeping part, good arrangement, great care, thorough knowledge of all warlike stores, both in their active and passive state, and scrupulous exactness in the custody, issue and receipt of stores. For fuller details the reader is referred to papers by Sir E. Collen, R.A., in vol. viii., and Lieut. C.E. Grover, R.E., in vol. vi. _Proceedings of R. Artillery Institution_. In England the Royal Arsenal, Woolwich, manufactures and stores the requirements of the army and navy (see WOOLWICH).

ARSENIC (symbol As, atomic weight 75.0), a chemical element, known to the ancients in the form of its sulphides. Aristotle gave them the name [Greek: sanoarakae], and Theophrastus mentions them under the name [Greek: arsenikon]. The oxide known as white arsenic is mentioned by the Greek alchemist Olympiodorus, who obtained it by roasting arsenic sulphide. These substances were all known to the later alchemists, who used minerals containing arsenic in order to give a white colour to copper. Albertus Magnus was the first to state that arsenic contained a metal-like substance, although later writers considered it to be a bastard or semi-metal, and frequently called it _arsenicum rex_. In 1733 G. Brandt showed that white arsenic was the calx of this element, and after the downfall of the phlogiston theory the views concerning the composition of white arsenic were identical with those which are now held, namely that it is an oxide of the element.

Arsenic is found in the uncombined condition in various localities, but more generally in combination with other metals and sulphur, in the form of more or less complex sulphides. Native arsenic is usually found as granular or curvilaminar masses, with a reniform or botryoidal surface. These masses are of a dull grey colour, owing to surface tarnish; only on fresh fractures is the colour tin-white with metallic lustre. The hardness is 3.5 and the specific gravity 5.63-5.73. Crystals of arsenic belong to the rhombohedral system, and have a perfect cleavage parallel to the basal plane; natural crystals are, however, of rare occurrence, and are usually acicular in habit. Native arsenic occurs usually in metalliferous veins in association with ores of antimony, silver, &c.; the silver mines of Freiberg in Saxony, St Andreasberg in the Harz, and Chanarcillo in Chile being well-known localities. Attractive globular aggregates of well-developed radiating crystals have been found at Akatani, a village in the province Echizen, in Japan.

Arsenic is a constituent of the minerals arsenical iron, arsenical pyrites or mispickel, tin-white cobalt or smaltite, arsenical nickel, realgar, orpiment, pharmacolite and cobalt bloom, whilst it is also met with in small quantities in nearly all specimens of iron pyrites. The ordinary commercial arsenic is either the naturally occurring form, which is, however, more or less contaminated with other metals, or is the product obtained by heating arsenical pyrites, out of contact with air, in earthenware retorts which are fitted with a roll of sheet iron at the mouth, and an earthenware receiver. By this method of distillation the arsenic sublimes into the receiver, leaving a residue of iron sulphide in the retort. For further purification, it may be sublimed, after having been previously mixed with a little powdered charcoal, or it may be mixed with a small quantity of iodine and heated. It can also be obtained by the reduction of white arsenic (arsenious oxide) with carbon. An electro-metallurgical process for the extraction of arsenic from its sulphides has also been proposed (German Patent. 67,973). These compounds are brought into solution by means of polysulphides of the alkali metals and the resultant liquor run into the cathode compartment of a bath, which is divided by diaphragms into a series of anode and cathode chambers; the anode divisions being closed and gas-tight, and containing carbon or platinum electrodes. The arsenic solution is decomposed at the cathode, and the element precipitated there.

Arsenic possesses a steel-grey colour, and a decided metallic lustre; it crystallizes on sublimation and slow condensation in rhombohedra, isomorphous with those of antimony and tellurium. It is very brittle. Its specific gravity is given variously from 5.395 to 5.959; its specific heat is 0.083, and its coefficient of linear expansion 0.00000559 (at 40 deg. C.). It is volatile at temperatures above 100 deg. C. and rapidly vaporizes at a dull red heat. It liquefies when heated under pressure, and its melting point lies between 446 deg. C. and 457 deg. C. The vapour of arsenic is of a golden yellow colour, and has a garlic odour. The vapour density is 10.6 (air = 1) at 564 deg. C., corresponding to a tetratomic molecule As4; at a white heat the vapour density shows a considerable lowering in value, due to the dissociation of the complex molecule.

By condensing arsenic vapour in a glass tube, in a current of an indifferent gas, such as hydrogen, amorphous arsenic is obtained, the deposit on the portion of the tube nearest to the source of heat being crystalline, that farther along (at a temperature of about 210 deg. C.) being a black amorphous solid, while still farther along the tube a grey deposit is formed. These two latter forms possess a specific gravity of 4.710 (14 deg. C.) [A. Bettendorff, _Annalen_, 1867, 144, p. 110], and by heating at about 358 deg.-360 deg. C. pass over into the crystalline variety. Arsenic burns on heating in a current of oxygen, with a pale lavender-coloured flame, forming the trioxide. It is easily oxidized by heating with concentrated nitric acid to arsenic acid, and with concentrated sulphuric acid to arsenic trioxide; dilute nitric acid only oxidizes it to arsenious acid. It burns in an atmosphere of chlorine forming the trichloride; it also combines directly with bromine and sulphur on heating, while on fusion with alkalis it forms arsenites.

Arsenic and most of its soluble compounds are very poisonous, and consequently the methods used for the detection of arsenic are very important. For full accounts of methods used in detecting minute traces of arsenic in foods, &c., see "Report to Commission to Manchester Brewers' Central Association," the _Analyst_, 1900, 26, p. 8; "Report of Conjoint Committee of Society of Chemical Industry and Society of Public Analysts," the _Analyst_, 1902, 27, p. 48; T.E. Thorpe, _Journal of the Chemical Society_, 1903, 83, p. 774; O. Hehner and others, _Journal of Society of Chemical Industry_, 1902, 21, p. 94; also ADULTERATION.

Arsenic and arsenical compounds generally can be detected by (a)
_Reinsch's test_: A piece of clean copper is dipped in a solution of
an arsenious compound which has been previously acidified with pure
hydrochloric acid. A grey film is produced on the surface of the
copper, probably due to the formation of a copper arsenide. The
reaction proceeds better on heating the solution. On removing, washing
and gently drying the metal and heating it in a glass tube, a white
crystalline sublimate is formed on the cool part of the tube; under
the same conditions antimony does not produce a crystalline sublimate.

(b) _Fleitmann's test_ and _Marsh's test_ depend on the fact that
arsenic and its compounds, when present in a solution in which
hydrogen is being generated, are converted into arseniuretted
hydrogen, which can be readily detected either by its action on silver
nitrate solution or by its decomposition on heating. In Fleitmann's
test, the solution containing the arsenious compound is mixed with
pure potassium hydroxide solution and a piece of pure zinc or
aluminium foil dropped in and the whole then heated. A piece of
bibulous paper, moistened with silver nitrate, is held over the mouth
of the tube, and if arsenic be present, a grey or black deposit is
seen on the paper, due to the silver nitrate being reduced by the
arseniuretted hydrogen. Antimony gives no reaction under these
conditions, so that the method can be used to detect arsenic in the
presence of antimony, but the test is not so delicate as either
Reinsch's or Marsh's method.

In the Marsh test the solution containing the arsenious compounds is
mixed with pure hydrochloric acid and placed in an apparatus in which
hydrogen is generated from pure zinc and pure sulphuric acid. The
arseniuretted hydrogen produced is passed through a tube containing
lead acetate paper and soda-lime, and finally through a narrow glass
tube, constricted at various points, and heated by a very small flame.
As the arseniuretted hydrogen passes over the heated portion it is
decomposed and a black deposit formed. Instead of heating the tube,
the gas may be ignited at the mouth of the tube and a cold surface of
porcelain or platinum placed in the flame, when a black deposit is
formed on the surface. This may be distinguished from the similar
antimony deposit by its ready solubility in a solution of sodium
hypochlorite. A blank experiment should always be carried out in
testing for small quantities of arsenic, to ensure that the materials
used are quite free from traces of arsenic. It is to be noted that the
presence of nitric acid interferes with the Marsh test; and also that
if the arsenic is present as an _arsenic_ compound it must be reduced
to the _arsenious_ condition by the action of sulphurous acid. Arsenic
compounds can be detected in the dry way by heating in a tube with a
mixture of sodium carbonate and charcoal when a deposit of black
amorphous arsenic is produced on the cool part of the tube, or by
conversion of the compound into the trioxide and heating with dry
sodium acetate when the offensive odour of the extremely poisonous
cacodyl oxide is produced. In the wet way, arsenious oxide and
arsenites, acidified with hydrochloric acid, give a yellow precipitate
of arsenic trisulphide on the addition of sulphuretted hydrogen; this
precipitate is soluble in solutions of the alkaline hydroxides,
ammonium carbonate and yellow ammonium sulphide. Under like conditions
arsenates only give a precipitate on long-continued boiling.

Arsenic is usually estimated either in the form of magnesium
pyroarsenate or as arsenic sulphide. For the pyroarsenate method it is
necessary that the arsenic should be in the _arsenic_ condition, if
necessary this can be effected by heating with nitric acid; the acid
solution is then mixed with "magnesia mixture" and made strongly
alkaline by the addition of ammonia. It is then allowed to stand
twenty-four hours, filtered, washed with dilute ammonia, dried,
ignited to constant weight and weighed, the filter paper being
incinerated separately after moistening with nitric acid. From the
weight of magnesium pyroarsenate obtained the weight of arsenic can be
calculated.

In the sulphide method, the arsenic should be in the _arsenious_ form.
Sulphuretted hydrogen is passed through the liquid until it is
thoroughly saturated, the excess of sulphuretted hydrogen is expelled
from the solution by a brisk stream of carbon dioxide, and the
precipitate is filtered on a Gooch crucible and washed with water
containing a little sulphuretted hydrogen and dried at 100 deg. C.; it
is then well washed with small quantities of pure carbon disulphide to
remove any free sulphur, again dried and weighed. Arsenic can also be
estimated by volumetric methods; for this purpose it must be in the
_arsenious_ condition, and the method of estimation consists in
converting it into the _arsenic_ condition by means of a standard
solution of iodine, in the presence of a cold saturated solution of
sodium bicarbonate.

The atomic weight of arsenic has been determined by many different
chemists. J. Berzelius, in 1818, by heating arsenious oxide with
excess of sulphur obtained the value 74.3; J. Pelouze (_Comptes
rendus_, 1845, 20, p. 1047) titrated arsenic chloride with silver
solution and obtained 75.0; and F. Kessler (_Pogg. Ann._ 1861, 113, p.
134) by converting arsenic trisulphide in hydrochloric acid solution
into arsenic pentasulphide also obtained 75.0.

_Compounds._--Arsenic forms two hydrides:--The _dihydride_, As2H2, is
a brown velvety powder formed when sodium or potassium arsenide is
decomposed by water. It is a somewhat unstable substance, decomposing
on being heated, with liberation of hydrogen. Arsenic _trihydride_
(arsine or arseniuretted hydrogen), AsH3, is formed by decomposing
zinc arsenide with dilute sulphuric acid; by the action of nascent
hydrogen on arsenious compounds, and by the electrolysis of solutions
of arsenious and arsenic acids; it is also a product of the action of
organic matter on many arsenic compounds. It is a colourless gas of
unpleasant smell, excessively poisonous, very slightly soluble in
water. It easily burns, forming arsenious oxide if the combustion
proceeds in an excess of air, or arsenic if the supply of air is
limited; it is also decomposed into its constituent elements when
heated. It liquefies at -40 deg. C. and becomes solid at -118.9 deg.
C. (K. Olszewski). Metals such as tin, potassium and sodium, when
heated in the gas, form arsenides, with liberation of hydrogen; and
solutions of gold and silver salts are reduced by the gas with
precipitation of metallic gold and silver. Chlorine, bromine and
iodine decompose arsine readily, the action being most violent in the
case of chlorine.

_Arsenic tribromide_, AsBr3, is formed by the direct union of arsenic
and bromine, and subsequent distillation from the excess of arsenic;
it forms colourless deliquescent prisms which melt at 20 deg.-25 deg.
C., and boil at 220 deg. C. Water decomposes it, a small quantity of
water leading to the formation of the _oxybromide_, AsOBr, whilst a
large excess of water gives arsenious oxide, As4O6.

Arsenic certainly forms two, or possibly three iodides. The
_di-iodide_, As2I4 or AsI2, which is prepared by heating one part of
arsenic with two parts of iodine, in a sealed tube to 230 deg. C.,
forms dark cherry-red prisms, which are easily oxidized, and are
readily decomposed by water. The _tri-iodide_, AsI3, prepared by
subliming arsenic and iodine together in a retort, by leading arsine
into an alcoholic iodine solution, or by boiling powdered arsenic and
iodine with water, filtering and evaporating, forms brick-red
hexagonal tables, of specific gravity 4.39, soluble in alcohol, ether
and benzene, and in a large excess of water; in the presence of a
small quantity of water, it is decomposed with formation of hydriodic
acid and an insoluble basic salt of the composition
4AsOI.3As4O6.24H2O. It combines with alkaline iodides to form very
unstable compounds. The _pentaiodide_, AsI5, appears to be formed when
a mixture of one part of arsenic and seven parts of iodine is heated
to 190 deg. C., but on dissolving the resulting product in carbon
bisulphide and crystallizing from this solvent, only the tri-iodide is
obtained.

_Arsenic trichloride_, AsCl3, is prepared by distilling white arsenic
with concentrated sulphuric acid and common salt, or by the direct
union of arsenic with chlorine, or from the action of phosphorus
pentachloride on white arsenic. It is a colourless oily heavy liquid
of specific gravity 2.205 (0 deg. C.), which, when pure and free from
chlorine, solidifies at -18 deg. C., and boils at 132 deg. C. It is
very poisonous and decomposes in moist air with evolution of white
fumes. With a little water it forms arsenic oxychloride, AsOCl, and
with excess of water it is completely decomposed into hydrochloric
acid and white arsenic. It combines directly with ammonia to form a
solid compound variously given as AsCl3.3NH3, or 2AsCl3.7NH3, or
AsCl3.4NH3.

_Arsenic trifiuoride_, AsF3, is prepared by distilling white arsenic
with fluorspar and sulphuric acid, or by heating arsenic tribromide
with ammonium fluoride; it is a colourless liquid of specific gravity
2.73, boiling at 63 deg. C.; it fumes in air, and in contact with the
skin produces painful wounds. It is decomposed by water into arsenious
and hydrofluoric acids, and absorbs ammonia forming the compound
2AsF3.5NH3. By the action of gaseous ammonia on arsenious halides at
-30 deg. C. to -40 deg. C., _arsenamide_, As(NH2)3, is formed. Water
decomposes it into arsenious oxide and ammonia, and when heated to 60
deg. it loses ammonia and forms _arsenimide_, As2(NH)3 (C. Hugot,
_Compt. rend._ 1904, 139, p. 54). For AsF5, see _Ber_., 1906, 39, p.
67.

Two oxides of arsenic are definitely known to exist, namely the
trioxide (white arsenic), As4O6, and the pentoxide, As2O5, while the
existence of a suboxide, As2O(?), has also been mooted. Arsenic
trioxide has been known from the earliest times, and was called
_Huttenrauch_ (furnace-smoke) by Basil Valentine. It occurs naturally
in the mineral claudetite, and can be artificially prepared by burning
arsenic in air or oxygen. It is obtained commercially by roasting
arsenical pyrites in either a Brunton's or Oxland's rotatory calciner,
the crude product being collected in suitable condensing chambers, and
afterwards refined by resublimation, usually in reverberatory
furnaces, the foreign matter being deposited in a long flue leading to
the condensing chambers. White arsenic exists in two crystalline forms
(octahedral and prismatic) and one amorphous form; the octahedral form
is produced by the rapid cooling of arsenic vapour, or by cooling a
warm saturated solution in water, or by crystallization from
hydrochloric acid, and also by the gradual transition of the amorphous
variety, this last phenomenon being attended by the evolution of heat.
Its specific gravity is 3.7; it is only slightly soluble in cold
water, but is more soluble in hot water, the solution reacting faintly
acid. The prismatic variety of the oxide can be obtained by
crystallization from a saturated boiling solution in potassium
hydroxide, or by the crystallization of a solution of silver arsenite
in nitric acid. Its specific gravity is 4.15. In the amorphous
condition it can be obtained by condensing the vapour of the oxide at
as high a temperature as possible, when a vitreous mass is produced,
which melts at 200 deg. C., has a specific gravity of 3.68-3.798, and
is more soluble in water than the crystalline variety.

Arsenious oxide is very poisonous. It acts as a reducing agent; it is
not convertible into the pentoxide by the direct action of oxygen; and
its solution is reduced by many metals (e.g. zinc, tin and cadmium)
with precipitation of arsenic and formation of arseniuretted hydrogen.
The solution of arsenious oxide in water reacts acid towards litmus
and contains tribasic arsenious acid, although on evaporation of the
solution the trioxide is obtained and not the free acid. The salts of
the acid are, however, very stable, and are known as arsenites. Of
these salts several series are known, namely the ortho-arsenites,
which are derivatives of the acid H3AsO3, the meta-arsenites,
derivatives of HAsO2, and the pyro-arsenites, derivatives of H4As2O5.
The arsenites of the alkali metals are soluble in water, those of the
other metals are insoluble in water, but are readily soluble in acids.
A neutral solution of an arsenite gives a yellow precipitate of silver
arsenite, Ag3AsO3, with silver nitrate solution, and a yellowish-green
precipitate (Scheele's green) of cupric hydrogen arsenite, CuHAsO3,
with copper sulphate solution. By the action of oxidizing agents such
as nitric acid, iodine solution, &c., arsenious acid is readily
converted into arsenic acid, in the latter case the reaction
proceeding according to the equation H3AsO3 + I2 + H2O = H3AsO4 + 2HI.
Arsenic pentoxide, As2O5, is most easily obtained by oxidation of a
solution of arsenious acid with nitric acid; the solution on
concentration deposits the compound 2H3AsO4.H2O (below 15 deg. C.),
which on being heated to a dark red heat loses its water of
crystallization and leaves a white vitreous mass of the pentoxide.
This substance dissolves slowly in water, forming arsenic acid; by
heating to redness it decomposes into arsenic and oxygen. It
deliquesces in moist air, and is easily reduced to arsenic by heating
with carbon.

Arsenic acid, H3AsO4, is prepared as shown above, the compound
2H3AsO4.H2O on being heated to 100 deg. C. parting with its water of
crystallization and leaving a residue of the acid, which crystallizes
in needles. On heating to 180 deg. C. it loses water and yields
pyroarsenic acid, H4As2O7, which at 200 deg. C. loses more water and
leaves a crystalline mass of meta-arsenic acid, HAsO3. These latter
two acids are only stable in the solid state; they dissolve readily in
water with evolution of heat and immediate transformation into the
ortho-arsenic acid. The salts of arsenic acid, termed arsenates, are
isomorphous with the phosphates, and in general character and
reactions resemble the phosphates very closely; thus both series of
salts give similar precipitates with "magnesia mixture" and with
ammonium molybdate solution, but they can be distinguished by their
behaviour with silver nitrate solution, arsenates giving a
reddish-brown precipitate, whilst phosphates give a yellow
precipitate.

There are three known compounds of arsenic and sulphur, namely,
realgar As2S2, orpiment As2S3, and arsenic pentasulphide As2S5.
Realgar occurs native in orange prisms of specific gravity 3.5; it is
prepared artificially by fusing together arsenic and sulphur, but the
resulting products vary somewhat in composition; it is readily fusible
and sublimes unchanged, and burns on heating in a current of oxygen,
forming arsenic trioxide and sulphur dioxide.

Orpiment (_auri pigmentum_) occurs native in pale yellow rhombic
prisms, and can be obtained in the amorphous form by passing a current
of sulphuretted hydrogen gas through a solution of arsenious oxide or
an arsenite, previously acidified with dilute hydrochloric acid. It
melts easily and volatilizes. It burns on heating in air, and is
soluble in solutions of alkaline hydroxides and carbonates, forming
thioarsenites, As2S3 + 4KHO = K2HAsO3 + K2HAsS3 + H2O. On acidifying
the solution so obtained with hydrochloric acid, the whole of the
arsenic is reprecipitated as trisulphide, K2HAsO3 + K2HAsS3 + 4HCl =
4KCl + 3H2O + As2S3. Arsenic pentasulphide, As2S5, can be prepared by
fusing the trisulphide with the requisite amount of sulphur; it is a
yellow easily-fusible solid, which in absence of air can be sublimed
unchanged; it is soluble in solutions of the caustic alkalis, forming
thioarsenates, which can also be obtained by the action of alkali
polysulphides on orpiment. The thioarsenites and thioarsenates of the
alkali metals are easily soluble in water, and are readily decomposed
by the action of mineral acids. Arsenic compounds containing selenium
and sulphur are known, such as arsenic seleno-sulphide, AsSeS2, and
arsenic thio-selenide, AsSSe2. Arsenic phosphide, AsP, results when
phosphine is passed into arsenic trichloride, being precipitated as a
red-brown powder.