Chapter 42

Jaffe's Bibliotheca rerum germonicarum, vol. vi. pp. 132-897 (1873). E. Dummler has also published an authoritative edition, Epistolae aevi Carolini, vol. ii. pp. 1-481, in the Monumenta Germaniae, and has edited the poems in the same collection: Poetae latini aevi Carolini, vol. i. pp. 169-341.

AUTHORITIES.--Monnier, Alcuin et Charlemagne (Paris, 1863); K. Werner, Alkuin und sein Jahrhundert (Paderborn, 1876); J. Bass Mullinger, The Schools of Charles the Great and the Restoration of Education in the 9th Century (London, 1877); Aug. Molinier, Les Sources de l'histoire de France, vol. i. p. 191; G, Monod, Etudes critiques sur les sources de l'histoire carolingienne, part i. (Paris, (1898); C. J. B. Gaskoin, Alcuin: His Life and his Work (London, 1903). See further U. Chevalier, Repertoire des sources, &c., biobibliographie, s.v. Alcuin; Wattenbach, Deutschlands Geschichtsquellen (Stuttgart and Berlin, 1904), i, p. 186. (C. PF.)

ALCYONE, or HALCYONE, in Greek mythology, daughter of Aeolus and wife of Ceyx. For their presumption in calling themselves Zeus and Hera they were changed into birds--Alcyone into a diver, Ceyx into a kingfisher. According to another story, Ceyx was drowned and his body cast on the shore. His wife found the body, and the gods, out of compassion, changed both her and her husband into kingfishers. By command of Zeus (or Aeolus) the winds ceased to blow during their brooding-time, for seven days before and after the shortest day, that their eggs might not be carried away by the sea. Hence the expression ``halcyon days,'' used in ancient and modern times to denote a period of calm and tranquillity.

Apollonius Rhodius i. 1087; Ovid, Metam. xi. 410 et seq.; Hyginus, Fabulae, 65.

ALDABRA, the collective name of a group of islands in the Indian Ocean, forming part of the British colony of Seychelles. They lie in 9 deg. 30' S., 46 deg. E., are 265 m. N.W. of the northern point of Madagascar and 690 m. S.W. of Mahe, the principal island of the Seychelles archipelago. The Comoro Islands lie 220 m. S. by W. of Aldabra. The Aldabra Islands constitute an atoll consisting of an oval ring of land, some 40 m. in circumference and about 1 1/2 m. broad, enclosing a shallow lagoon. Channels divide the ring into four islands. Grande Terre or South Island forms three-fifths of the circumference. The other islands are West Island or Ile Picard, Polymnie and Middle Island. There are in addition several islets in the lagoon, the most important being Ile Michel. The total land area is estimated at about 60 sq. m., the lagoon, 16 m. long and 4 m. wide, covering a somewhat larger area. Pop. (1906) 127. The islands rise from 20 to 80 ft. above the sea, and consist of rugged coral rock and limestone, there being very little soil. The sea-face is generally overhanging cliff, but in a few places are sandy beaches and low sandhills. Dense scrub covers most of the land, but the inner (lagoon) shore is everywhere bounded by mangrove swamps. The flora and fauna of the islands present features of unusual interest. They are chiefly noted as the habitat of the gigantic land tortoise (Testudo elephantina), now carefully preserved, and of several rare and peculiar birds, including a rail (Dryolimnas aldabranus), an ibis (Ibis abbottii) and a dove (Alectroenas sganzini.) Crustacea are abundant. They include oysters, crabs of great size, and a small mussel, found in enormous numbers. The flora includes mangroves, Rubiaceae, Sapotaceae and other forms requiring more than pure coralline material for their growth. Writing of the fauna and flora generally, Mr R. Dupont, curator of the Botanic station at Mahe, who visited Aldabra in 1906. says: ``The specimens represented, besides being partly peculiar, mostly belong to the Mascarenes, Madagascar and Comoros species. Many species are also common to East Africa and to India. . . . The predominant species are Madagascar plants and birds, which are carried by the currents and the winds. . . . There are comparatively few (10) species of plants which are endemic as far as the flora has been investigated, and it is probable that most of them are also existing in the Comoros, where the flora is not well known. . . . Endemic inferior animals and mammals are practically non-existent, except two bats and one scorpion, which are allied to Madagascar species or introduced. The reptiles (tortoises) are also nearly allied to the Mascarenes and Madagascar species which once existed. With regard to birds and land shells the relation is much closer to the Comoros species, and the latter, of which I have collected seven species besides Rachis aldabrae, may serve to point out more than the birds the land connexion of Aldabra with the neighbouring countries.'' Aldabra, however, although situated in that region of the Indian Ocean which forms part of the site of the Indo-Madagascar continent of the Secondary period, is not a peak of the submerged land. It has been built up from the sunken remains of the old continent by a deposit, in the opinion of Professor A. Voeltzkow, of foraminiferal remains (mostly coccoliths and rhabdoliths). In any case, however Aldabra was formed, there can be no suggestion of its ever having been joined to any other land (Stanley Gardiner). Dupont states that at Aldabra the coral foundation is totally above water. The coral limestone of the atoll has a peculiar vitrified appearance and gives out a ringing sound when struck or simply walked on. The coral is generally reddish, but the colouring ranges from light yellow to chocolate-brown.

Aldabra was visited by Portuguese navigators in 1511. The islands were already known to the Arabs, from whom they get their name. They became in the middle of the 18th century dependencies of the French establishments at Bourbon (Reunion), whence expeditions were made for the capture of the giant tortoises. In 1810 with Mauritius, Bourbon, the Seychelles and other islands, Aldabra passed into the possession of Great Britain. The inhabitants are emigrants from the Seychelles. Goats are bred and coco-nuts cultivated, but fishing is the chief industry. With other outlying islands Aldabra is held under lease from the Seychelles government, the lessees having exclusive trading privileges.

See R. Dupont, Report on a Visit of Investigation to . . . the Aldabra Group of the Seychelles Islands (Seychelles, 1907); Dr Abbott in Proceedings, United States National Museum (Washington, 1894); A. Voeltzkow in Abh. der Senckenbergischen Naturferschenden Ges. vol. xxvi. part iv. (1901); J. S. Gardiner, ``The Indian Ocean,'' Geo. Journ. Oct. 1906.

ALDBOROUGH, a village in the Ripon parliamentary division of the West Riding of Yorkshire, England, 16 m. W.N.W. of York, and 1 m. E. of the market town of Boroughbridge, which has a station on a branch of the North-Eastern railway. Aldborough formerly returned two members to parliament, but was disfranchised by the Reform Act of 1832. The place is remarkable from its numerous ancient remains. It was the Isurium Brigantum of the Romans, originally perhaps a capital of the Brigantes tribe, and afterwards a Romano-British town of considerable size. Inscriptions, beautiful mosaics and other traces of comfortable houses have been found, with many potsherds, coins and bronze, iron and other objects; and a large part of the town walls, several mosaics and parts of buildings, can be seen. A fine collection is kept in the Museum Isurianum in the grounds of the manor-house.

ALDEBURGH [ALDBOROUGH], a market town and municipal borough in the Eye parliamentary division of Suffolk, England, the terminus of a branch of the Great Eastern railway, 99 1/2 m. N.E. by E. from London. Area, 1629 acres. Pop. (1901) 2405. The surrounding district is open and somewhat bleak, but a fine stretch of sand fringes the shallow inlet of the North Sea known as Aldeburgh Bay. To the W. the river Alde broadens as if into an estuary, but its outflow is here prevented by the sand, and it runs south for nearly 10 m. parallel with the shore. The sandbanks have arrested the encroachments of the sea, which submerged a former site of Aldeburgh. The church of St Peter and St Paul is Perpendicular, largely restored, and contains a monument to the poet George Crabbe, born here on the 24th of December 1754. A small picturesque Moot Hall of the 16th century is used for corporation meetings. Slaughden Quay on the Alde admits small vessels, and fishing is carried on. Aldeburgh is governed by a mayor, 4 aldermen and 12 councillors.

Aldeburgh (Aldburc) takes its name from the river Alde on which it stands. It is not mentioned in pre-Conquest records, but at the Domesday survey most of the land was held by Robert Malet, a Norman. In 1155 the manor was granted to the abbey of St John of Colchester, later to Cardinal Wolsey, and on his disgrace, to Thomas Howard, duke of Norfolk, to whom Elizabeth in 1567 granted a market on Saturday. In the 16th century Aldeburgh was a place of considerable commercial importance, due, no doubt, to its position on the sea-coast. Aldeburgh claims to be a borough by prescription: the earliest charter is that granted by Henry VIII. in 1529. Edward VI. in 1548 raised it to the rank of a free borough, granting a charter of incorporation and a market on Wednesday. Later charters were granted by Philip and Mary in 1553, by Elizabeth in 1558 and 1567, by James I. (who granted two annual fairs) in 1606, and by Charles I. in 1631 and 1637. The corporation included 2 bailiffs, 10 capital and 24 inferior burgesses, until the Municipal Corporations Act 1883. The fairs and markets became so unimportant that they were discontinued about the middle of the 19th century. The town returned two members to Elizabeth's parliament of 1572, and continued to be so represented till the Reform Bill of 1832 disfranchised it. Frequent disastrous incursions of the sea in the 18th century reduced Aldeburgh to a mere fishing village. In recent years it has grown as a seaside resort, with excellent golf-links.

See John Kirby, The Suffolk Traveller (2nd ed., 1764); N. F. Hele, Notes about Aldeburgh (1870); Victoria County History--Suffolk.

ALDEGREVER, or ALDEGRAF, HEINRICH (1502-1558), German painter and engraver, was born at Paderborn, from which he removed in early life to Soest, where he died. From the close resemblance of his style to that of Albrecht Durer he has sometimes been called the Albert of Westphalia. His numerous engravings, chiefly from his own designs, are delicate and minute, though somewhat hard in style, and entitle him to a place in the front rank of the so-called ``Little Masters.'' There is a good collection in the British Museum. Specimens of his painting are exceedingly rare. Five pictures are in continental galleries, but the genuineness of the works in the Vienna and Munich collections attributed to him is at least doubtful, the only unchallenged example being a portrait of Engelbert Therlaen (1551) in the Berlin Museum.

ALDEHYDES, a class of chemical compounds of the general formula R.CHO (R = an alkyl or an aryl group). The name is derived from alcohol dehydrogenatum in allusion to the fact that they may be prepared by the oxidation of alcohols. The lower members of the series are neutral liquids possessing a characteristic smell; they are soluble in water and are readily volatile (formaldehyde, however, is a gas at ordinary temperatures). As the carbon content of the molecule increases, they become less soluble in water, and their smell becomes less marked with the increase in boiling point, the highest members of the series being odourless solids, which can only be distilled without decomposition in vacuo.

The aldehydes may be prepared by the careful oxidation of primary alcohols with a mixture of potassium dichromate and sulphuric acid,--3R.CH2OH + K2 Cr2O7 + 4H2SO4 = K2SO4 + Cr2(SO4)3 + 7H2O + 3R.CHO; by distilling the calcium salts of the fatty acids with calcium formate; and by hydrolysis of the acetals. L. Bouveault (Bull. soc. chim., 1904 [3], 31, p. 1306) prepares aldehydes by the gradual addition of disubstituted formamides (dissolved in anhydrous ether) to magnesium alkyl haloids, the best yields being obtained by the use of diethyl formamide. Secondary reactions take place at the same time, yielding more particularly hydrocarbons of the paraffin series. G. Darzens (Comptes Rendus, 1904, 139, p. 1214) prepares esters of disubstituted glycidic acids, by condensing the corresponding ketone with monochloracetic ester, in the presence of sodium ethylate. These esters on hydrolysis yield the free acids, which readily decompose, with loss of carbon dioxide and formation of an aldehyde,

/R /CRR1 /CRR1 OC< + Cl.CH2.COOC2H5 --> O< | --> O< | \R1 \CH.COOC2H5 \CH.COOH

--> CO2 + CHRR1.CHO.

In the German Patent 157573 (1904) it is shown that by the action of at least two molecular proportions of an alkyl formate on two molecular proportions of a magnesium alkyl or aryl haloid, a complex addition compound is formed, which readily decomposes into a basic magnesium salt and an aldehyde,

C6H5MgBr + HCOOR --> RO.CH.C6H5.OMgBr --> MgBr.OR + C6H5CHO.

The aldehydes are characterized by their great chemical reactivity. They act as reducing agents, silver nitrate in the presence of ammonia being rapidly reduced to the condition of metallic silver. They are easily oxidized to the corresponding fatty acid, in many cases simply by exposure to air. Nascent hydrogen reduces them to primary alcohols, and phosphorus pentachloride replaces the carbonyl oxygen by chlorine. They form many addition compounds, combining with ammonia to form aldehyde ammonias of the type R.CH(OH).NH2. These are colourless crystalline compounds, which are most readily prepared by passing ammonia gas into an ethereal solution of the aldehyde. With sodium bisulphite they form the so-called bisulphite compounds R.CH(OH).SO3Na, which are readily resolved into their components by distillation with dilute acids, and are frequently used for the preparation of the pure aldehyde.

With hydrocyanic acid aldehydes form the cyanhydrins R.CH(OH).CN. They react with hydroxylamine and phenylhydrazine, with the formation of aldoximes and hydrazones. (For the isomerism of the aldoximes see OXIMES.) The hydrazones are crystalline substances which are of value in the characterization of the aldehydes. Both oximes and hydrazones, on boiling with dilute acid, regenerate the parent aldehyde. The hydrazones are best prepared by mixing the aldehyde with phenylhydrazine in dilute acetic acid solution, in the absence of any free mineral acid. Semioxamazid, NH2.CO.CO.NH.NH2, has also been employed for the identification of aldehydes (W. Kerp and K. Unger, Berichte, 1897, 30. p. 585). Aldehydes are converted into resins by the action of caustic alkalies. On heating with alcohols to 100 deg. C. they form acetals, and they also form condensation products with para-amido-di-methyl-aniline (A. Calm, Berichte, 1884, 17, p. 2939). They react with the zinc alkyls to form addition products, which are decomposed by water with formation of secondary alcohols (K. Thurnlach, Annalen, 1882, 213, p. 369) thus:-- Zn(C2H5)2 H2O /C2H5 /C2H5 CH3.CHO --> CH3.CH< --> CH3.CH< + ZnO + C2H6. \OZnC2H5 \OH The reaction is a general one for all aldehydes with zinc methyl and zinc ethyl, but not with the higher zinc alkyls. V. Grignard (Comptes Rendus, 1900 et seq.) showed that aldehydes combine with magnesium alkyl iodides (in absolute ether solution) to form addition products, which are decomposed by water with the formation of secondary alcohols, thus from acetaldehyde and magnesium methyl iodide, isopropyl alcohol is obtained.

H2O /CH3 CH3.CHO + CH3MgI --> CH3.CH< --> (CH3)2CH.OH + MgI.OH. \OMgI The lower members of the aliphatic series are characterized by their power of polymerization (see FORMALIN, and the account of Acetaldehyde below), and also by the so-called ``aldol'' condensation, acetaldehyde in this way forming aldol, CH3.CHOH.CH2.CHO. These aldols generally lose the elements of water readily and pass into unsaturated compounds; aldol itself on distillation at ordinary atmospheric pressure gives crotonaldehyde, CH3.CH:CH.CHO.

Aldehydes are characterized by the reddish-violet colour which they give with a solution of fuchsine that has been decolorized by sulphurous acid (H. Schiff, Ann., 1866, 140, p. 131). With diazobenzene sulphonic acid in the presence of alkali and a trace of sodium amalgam, a reddish-violet coloration is formed on standing (E. Fischer, Ber., 1883, 16, p. 657). A. Angeli (Gazz. chim. Ital., 1896, 22, ii. 17) has shown that aldehydes in the presence of nitrohydroxylaminic acid form hydroxamic acid. The aldehydes condense readily with acetoacetic ester in the presence of ammonia, to pyridines (see PYRIDINE), whilst O. Doebner and W. v. Miller (Ber., 1892, 25, p. 2864; 1896, 29, p. 59) have shown that in the presence of aniline and sulphuric acid they give substituted quinolines. (See also C. Beyer, Ber., 1887, 20, p. 1908). The chief aldehydes are shown in the following table:--

_____________________________________________________________________________ | Name. | Formula | Boiling | Melting| | | | Point. | Point.| |--------------------|-----------------------------------|---------|--------| | Formaldehyde | H.CHO |-21 deg. | | | Acetaldehyde | CH3.CHO | 20.8 deg. | | | Propyl aldehyde | CH3.CH2.CHO | 49 deg. | | | n-Butyl '' | CH3.(CH2)2.CHO | 75 deg. | | | iso- '' '' | (CH3)2.CH.CHO | 61 deg. | | | n-Valeryl '' | CH3.(CH2)3.CHO |103 deg. | | | iso- '' '' | (C4H9.CHO | 92 deg. | | | Oenanthyl '' | CH3.(CH2)5.CHO |155 deg. | | | Capric '' | CH3.(CH2)8.CHO |121 deg. | | | Lauric '' | CH3.(CH2)10.CHO | |44.5 deg. | | Myristic '' | CH3.(CH2)12.CHO | |52.5 deg. | | Palmitic '' | CH3.(CH2)14.CHO | |58.5 deg. | | Stearic '' | CH3.(CH2)16.CHO | |63.5 deg. | |--------------------|-----------------------------------|---------|--------| | Acrolein | | | | | ally aldehyde | CH2 : CH.CHO | 52 deg. | | | Crotonic '' | CH3.CH : CH.CHO |104 deg. | | | Tiglic '' | | | | | (guaiacol) | CH3.CH : C.CH3.CHO |116 deg. | | |--------------------|-----------------------------------|---------|--------| | Proargylic A. | CH : C.CHO | 59 deg. | | |--------------------|-----------------------------------|---------|--------| | Benzaldehyde | C6H5.CHO |179 deg. | | | {o | |200 deg. | | | Toluicaldehyde{m | C6H4.CH3.CHO |199 deg. | | | {p | |204 deg. | | | Cumic '' | C6H4.C3H7.CHO |235 deg. | | | Cinnamic '' | C6H5.CH : CH.CHO |247 deg. | | |____________________|___________________________________|_________|________|

For formaldehyde see FORMALIN. Acetaldehyde, CH3.CHO, was first noticed by C. Scheele in 1774 and isolated and investigated by J. v. Liebig (Annalen, 1835, 14, p. 133). It is prepared by oxidizing ethyl alcohol with dilute sulphuric acid and potassium bichromate, and is a colourless liquid of boiling point 20.8 deg. C., possessing a peculiar characteristic smell. Its specific gravity is 0.8009 (0 deg. C.). It is miscible in all proportions with alcohol, ether and water. It is readily polymerized, small quantities of hydrochloric acid, zinc chloride, carbonyl chloride, &c. converting it, at ordinary temperatures, into paraldehyde, (C2H4O)3, a liquid boiling at 124 deg. C. and of specific gravity 0.998 (15 deg. C.). Paraldehyde is moderately soluble in water, and when distilled with sulphuric acid is reconverted into the ordinary form. Metaldehyde, (C2H4O)3, is produced in a similar way to paraldehyde, but at lower temperatures (e.g. in presence of a freezing mixture). It is a crystalline solid, which sublimes at 112 deg. -115 deg. C. It is insoluble in water, and is only slightly soluble in alcohol and ether. When heated in a sealed tube at 120 deg. C. it is completely converted into the ordinary form. Paraldehyde is oxidized by dilute nitric acid, with formation of much glyoxal, (CHO)2. (For trichloracetaldehyde see CHLORAL.)

By the action of acetaldehyde on alcohol at 100 deg. C., acetal, CH3.CH(OC2H5)2, is produced. It may also be prepared by oxidizing ethyl alcohol with manganese dioxide and sulphuric acid (A. Wurtz). It is a colourless liquid of specific gravity 0.8314 (20 deg. /4 deg. ) (J. W. Bruhl) and boiling point 104 deg. C. Dilute acids readily transform it into alcohol and aldehyde, and chromic acid oxidizes it to acetic acid. Chlor- and brom-acetals have been described.

Thioaldehydes are also known, and are obtained by leading sulphuretted hydrogen into an aqueous solution of acetaldehyde. By this means a mixture is obtained which by distillation or the action of hydrochloric acid yields trithioaldehyde, (C2H4S)3. For the constitution of these substances see E. Baumann and E. Fromm (Berichte, 1891, 24, p. 1426). Aldehyde ammonia, CH3.CH(OH).NH2, is formed when dry ammonia gas is passed into an ethereal solution of acetaldehyde. It crystallizes in glistening rhombohedra, melting at 70 deg. -80 deg. C., and boiling at 100 deg. C. It is completely resolved into its components when warmed with dilute acids.

The higher aldehydes of the series resemble acetaldehyde in their general behaviour. Unsaturated aldehydes are also known, corresponding to the olefine alcohols; they show the characteristic properties of the saturated aldehydes and can form additive compounds in virtue of their unsaturated nature. The simplest member of the series is acrolein, C3H4O or CH2 : CH.CHO, which can be prepared by the oxidation of allyl alcohol, or by the abstraction of the elements of water from glycerin by heating it with anhydrous potassium bisulphate. It is also produced by the action of sodium on a mixture of epichlorhydrin and methyl iodide, C3H5OCl + CH3I + 2Na = C3H4O + NaI + NaCl + CH4. It is a colourless liquid, with a very pungent smell, and attacks the mucous membrane very rapidly. It boils at 52.4 deg. C. and is soluble in water. It oxidizes readily: exposure to air giving acrylic acid, nitric acid giving oxalic acid, bichromate of potash and sulphuric acid giving carbon dioxide and formic acid. It combines with bromine to form a dibromide, from which E. Fischer, by the action of baryta water, obtained the synthetic sugars a- and b-acrose (Berichte, 1889, 22, p. 360). Metacrolein, (C3H4O)3, is a polymer of acrolein. By passing acrolein vapour into ammonia, acrolein ammonia, C6H9NO, is obtained. It is a reddish amorphous mass, insoluble in alcohol, and when distilled yields picoline (methyl pyridine) (A. Baeyer, Ann., 1870, 155, p. 283). Citronellal, rhodinal and geranial are also unsaturated aldehydes (see TERPENES.)

The aromatic aldehydes resemble the aliphatic aldehydes in most respects, but in certain reactions they exhibit an entirely different behaviour. They do not polymerize, and in the presence of caustic alkalies do not resinify, but oxidize to alcohols and acids (see BENZALDEHYDE for Cannizzaro's reaction). When heated with alcoholic potassium cyanide they are converted into benzoins (q.v..) Vanillin does not give the Cannizzaro reaction, but with alcoholic potash forms vanillic acid, HOOC(1).C6H3.OCH3 (3).OH(4), and vanilloin. With ammonia, benzaldehyde does not form an aldehyde ammonia, but condenses to hydrobenzamide, ( C6H5CH)3N2, with elimination of water. Cumic aldehyde (cuminol), (CH3)2CH(1)C6H4.CHO(4), is found in Roman caraway oil and in oil of the water hemlock. It is a liquid, boiling at 235 deg. C., and has a specific gravity of 0.973. On distillation with zinc dust it forms cymene (1.4 methyl isopropyl benzene).

Salicylic aldehyde (ortho-hydroxybenzaldehyde), HO(1). C6H4.CHO(2), an aromatic oxyaldehyde, is a colourless liquid of boiling point 196 deg. C. and specific gravity 1.172 (15 deg. ). It is found in the volatile oils of Spiraea, and can be obtained by the oxidation of the glucoside salicin, (C13H18O7), which is found in willow bark. It is usually prepared by the so-called ``Reimer'' reaction (Ber., 1876, 9, p. 1268), in which chloroform acts on phenol in the presence of a caustic alkali,

C5H5OH + CHCl3 + 4KHO = 3KCl + 3H2O + KO.C6H4.CHO, some para-oxybenaldehyde being formed at the same time. It is volatile (para-oxybenzaldehyde is not) and gives a violet coloration with ferric chloride. For dioxybenzaldehydes and their derivatives see PIPERONAL and VANILLIN.

Cinnamic aldehyde (b-phenyl acrolein), C6H5.CH : CH.CHO, an unsaturated aromatic aldehyde, is the chief constituent of cinnamon oil. It is prepared by oxidizing cinnamyl alcohol, or by the action of sodium ethylate on a mixture of benzaldehyde and acetaldehyde. It is a colourless aromatic-smelling oily liquid, which boils at 247 deg. C. and readily oxidizes on exposure.

By condensation of aldehydes with pyruvic acid and naphthylamines, the a-alkyl-naphthoquinoline-g-carboxylic acids are produced; the same reaction takes place with the aromatic amines generally (O. Doebner, Ann. 1804, 281, p. 1),

COOH | / \ COOH / \ / \ | | + | + R.CHO = | | | + 2H2O + 2H. \ / \NH2 CO.CH3 \ / \N/ \R

ALDEN, JOHN (1599?-1687), one of the ``Pilgrims'' who in 1620 emigrated to America on the ``Mayflower'' and founded the Plymouth Colony. According to William Bradford's History of the Plimoth Plantation, he was hired as a cooper at Southampton, ``where the ship victuled,'' just before the voyage, ``and being a hopfull yong man, was much desired.'' He was one of the first settlers of Duxbury, Massachusetts, where he lived during the greater part of his life, and from 1633 until 1675 he was an ``Assistant'' to the governor of the colony, frequently serving as acting governor. At the time of his death, at Duxbury, on the 12th of September 1687, he was the last male survivor of the signers of the ``Mayflower Compact'' of 1620, and with the exception of Mary Allerton was the last survivor of the ``Mayflower'' company. He is remembered chiefly because of a popular legend, put into verse as The Courtship of Miles Standish by Henry W. Longfellow, concerning his courtship of Priscilla Mullins, whom he married in 1623, after having wooed her first on behalf of his friend, Miles Standish.

ALDER, a genus of plants (Alnus) belonging to the order Betulaceae, the best-known of which is the common alder (A. glutinosa.) The genus comprises a few species of shrubs or trees, seldom reaching a large size, distributed through the North Temperate zone, and in the New World passing along the Andes southwards to Chile. The British species A. glutinosa is confined to the Old World. This tree thrives best in moist soils, has a shrubby appearance, and grows under favourable circumstances to a height of 40 or 50 ft. It is characterized by its short-stalked roundish leaves, becoming wedge-shaped at the base and with a slightly toothed margin. When young they are somewhat glutinous, whence the specific name, becoming later a dark olive green. As with other plants growing near water it keeps its leaves longer than do trees in drier situations, and the glossy green foliage lasting after other trees have put on the red or brown of autumn renders it valuable for landscape effect. The stout cylindrical male catkins are pendulous, reddish in colour and 2 to 4 in. long; the female are smaller, less than an inch in length and reddish-brown in colour, suggesting young fir-cones. When the small winged fruits have been scattered the ripe, woody, blackish cones remain, often lasting through the winter. The alder is readily propagated by seeds, but throws up root-suckers abundantly. It is important as coppice-wood on marshy ground. The wood is soft, white when first cut and turning to pale red; the knots are beautifully mottled. Under water the wood is very durable, and it is therefore used for piles. The supports of the Rialto at Venice, and many buildings at Amsterdam, are of alder-wood. Furniture is sometimes made from the wood, and it supplies excellent charcoal for gunpowder. The bark is astringent; it is used for tanning and dyeing.

ALDER-FLY, the name given to neuropterous insects of the family Sialidae, related to the ant-lions, with long filamentous antennae and four large wings, of which the anterior pair is rather longer than the posterior. The females lay a vast number of eggs upon grass stems near water. The larvae are aquatic, active, armed with strong sharp mandibles, and breathe by means of seven pairs of abdominal branchial filaments. When full sized they leave the water and spend a quiescent pupal stage on the land before metamorphosis into the sexually mature insect. Sialis lutaria is a well-known British example. In America there are two genera, Corydalis and Chauliodes, which are remarkable for their relatively gigantic size and for the immense length and sabre-like shape of the mandibles.

ALDERMAN (from A.-S. ealdorman, compounded of the comparative degree of the adjective eald, old, and man), a term implying the possession of an office of rank or dignity, and, in modern times, applied to an office-bearer in the municipal corporations and county councils of England and Wales,and in the municipal corporations of Ireland and the United States. Among the Anglo-Saxons, earls, governors of provinces and other persons of distinction received this title. Thus we read of the aldermannus totius Angliae, who seems to have corresponded to the officer afterwards styled capitalis justiciarius Angliae, or chief-justice of England; the aldermannus regis, probably an occasional magistrate, answering to the modern justice of assize, or perhaps an officer whose duty it was to prosecute for the crown; and aldermannus comitatus, a magistrate with a middle rank between what was afterwards called the earl and the sheriff, who sat at the trial of causes with the bishop and declared the common law, while the bishop proceeded according to ecclesiastical law. Besides these, we meet with the titles of aldermannus civitatis, burgi, castelli, hundredi sive wapentachii, &c. In England, before the passing of the Municipal Corporations Act, their functions varied according to the charters of the different boroughs. By the Municipal Corporations Act 1835, and other acts, consolidated by the Municipal Corporations Act 1882, the aldermen are elected by the councillors for six years, one-half going out every three years. The number of councillors in each borough varies according to its magnitude. One-fourth of the municipal council consists of aldermen and three-fourths of councillors. In the counties, too, the number of aldermen is one-third of the number of councillors, except in London, where it is one-sixth. In the municipal corporations of Scotland there is no such title as alderman, the office-bearers of corresponding rank there being termed bailies. The corporation of the city of London was not included in the Borough Reform Act, and the antiquated system remains there in full force. The court of aldermen consists of twenty-six, twenty-five of whom are elected for life by the freemen of the respective wards, who return two persons, one of whom the court of aldermen elect to supply the vacancy. The city is divided into twenty-six wards; twenty-four of these send up one alderman each, the other two combine to choose a twenty-fifth. The twenty-sixth alderman serves for the independent borough of Southwark (q.v.) and is appointed by the other aldermen, who generally select the senior from among themselves when a vacancy occurs. The lord mayor is elected from such of the aldermen as have served the office of sheriff; of these the Common Hall, which consists of the freemen of the different wards, select two, and the aldermen elect one of these to the mayoralty. The court of aldermen has the power of appointment to certain offices, exercises judicial functions in regard to licensing and in disputes connected with the ward election, has some power of disposal over the city cash and possesses magisterial control over the city, each alderman being a judge and magistrate for the whole city, and by virtue of his office exercising the functions of a justice of the peace. The aldermen are members of the court of common council, the legislative body of the corporation, which consists in all of 232 members, the remainder being elected annually by the freemen. In the United States aldermen form as a rule a legislative rather than a judicial body, although in some cities they hold courts and possess very considerable magisterial powers.

ALDERNEY (Fr. Aurigny), one of the Channel Islands, the northernmost of the principal members of the group, belonging to England. It lies in 49 deg. 43' N. and 2 deg. 12' W., 9 m. W. of Cape La Hague on the coast of Normandy. The harbour, on the north coast in the bay of Braye, is 25 m. from St Peter Port, Guernsey, by way of which outer communications are principally carried on, and 55 m. S. by E. of Portland Bill, the nearest point of England. The length of the island from N. E. to S. W. is 3 1/2 m., its average breadth 1 m., its area 1962 acres, and its population (1901) 2062.

The strait between the island and Cape La Hague, called the Race of Alderney (French Raz Blanchard), confined by numerous rocks and reefs off either coast, is rendered very dangerous in stormy weather by conflicting currents. Through this difficult channel the scattered remnant of the French fleet under Tourville escaped after the defeat of La Hogue in 1692. To the west is the narrower and also dangerous channel of the Swinge (Sinige), between Alderney and the uninhabited islets of Burhou, Ortach and others. West of these again are the Casquets, a group of rocks to which attaches a long record of shipwreck. Rocks and reefs fringe all the coasts of Alderney. The island itself is a level open tableland, which on the south-west and south falls abruptly to the sea in a majestic series of cliffs. The greatest elevation of the land is about 300 ft. Towards the north-west, north and east the less rocky coast is indented by several bays, with open sandy shores, of which those of Crabby, Brave, Corblets and Longy are the most noteworthy. South-west of Longy Bay, where the coast rises boldly, there is a remarkable projecting block of sandstone, called La Roche Pendante (Hanging Rock) overhanging the cliff. Sandstone (mainly along the north-east coast), granite and porphyry are the chief geological formations. There are a few streams, but water is obtained mainly from wells. Trees are scarce. The town of St Anne stands almost in the centre of the island overlooking and extending towards the harbour. Here are the courthouse, a gateway commemorating Albert, prince-consort, the clock tower, which belonged to the ancient parish church, and the modern church (1850), in Early English style, an excellent example of the work of Sir Gilbert Scott. The church is a memorial to the family of Le Mesurier, in which the hereditary governorship of the island was vested until the abolition of the office in 1825. There is a chain of forts round the north coast from Clanque Fort on the west to Fort Essex on the east; the largest is Fort Albert, above Brave Bay. In 1847 work was begun on a great breakwater west of the harbour, the intention being to provide a harbour of refuge, but although a sum exceeding one and a half million sterling was spent the scheme was unsuccessful. The soil of Alderney is light, fertile and well cultivated; grain and vegetables are grown and early potatoes are exported. A large part of the island is under grass, affording pasture for cattle. The well-known term ``Alderney cattle,'' however, has lost in great measure its former signification of a distinctive breed. Alderney is included in the bailiwick of Guernsey. It has a court consisting of a judge and six jurats, attorney-general, prevot, greffiero and sergent; but as a judicial court it is subordinate to that of Guernsey, and its administrative powers are limited to such matters as the upkeep of roads.

For its relations to the constitution of the bailiwick, and for the history of the island, see CHANNEL ISLANDS.

ALDERSHOT, an urban district in the Basingstoke parliamentary division of Hampshire, England, 34 m. S.W. by W. of London, on the London & South-Western and the South- Eastern & Chatham railways. It was a mere village till 1855, when Aldershot camp was established. Pop. (1891) 25,595; (1901) 30,974. Its germ is to be found in the temporary camp on Chobham Ridges, formed in 1853 by Lord Hardinge, the commander-in-chief, the success of which convinced him of the necessity of giving troops practical instruction in the field and affording the generals opportunities of manoeuvring large bodies of the three arms. He therefore advised the purchase of a tract of waste land whereon a permanent camp might be established. His choice fell on Aldershot, a spot also recommended by strategic reasons, being situated on the flank of any army advancing upon London from the south. Nothing came of Lord Hardinge's proposal till the experience of the Crimean campaign fully endorsed his opinion. The lands at Aldershot, an extensive open heath country, sparsely dotted by fir-woods and intersected by the Basingstoke canal, were then acquired by the crown. Wooden huts were erected in 1855, and permanent buildings to replace them were begun in 1881. Under the Barracks Act 1890, and the Military Works Act of 1897 and 1899, large sums were provided for completing the work. The former division of North and South camps and permanent barracks no longer obtains. North camp is now named Marlborough Lines, with a field artillery barrack and five infantry barracks called after Marlborough's victories. South camp is now named Stanhope Lines, after Mr Stanhope, who was secretary of state for war when the Barracks