Teil iii

. pp. 53 seq. (Berlin, 1844); T.W. Harris, _Insects injurious to Vegetation_ (Boston, U.S., 2nd ed., 1852); C.L. Koch, _Die Pflanzenlause Aphiden_ (Nuremberg, 1854); T. Hartig, _Die Familien der Blattwespen und Holzwespen_ (Berlin, 1860); Walsh, "On the Insects, Coleopterous, Hymenopterous and Dipterous, inhabiting the Galls of certain species of Willow," _Proc. Ent. Soc. Philadelphia_, iii. (1863-1864), pp. 543-644, and vi. (1866-1867), pp. 223-288; T.A. Marshall, "On some British Cynipidae," _Ent. Month. Mag._ iv. pp. 6-8, &c.; H.W. Kidd and Albert Muller, "A List of Gall-bearing British Plants," _ib._ v. pp. 118 and 216; G.L. Mayr, _Die mitteleuropaischen Eichengallen in Wort und Bild_ (Vienna, 1870-1871), and the translation of that work, with notes, in the _Entomologist_, vols. vii. seq.; also, by the same author, "Die Einmiethler der mitteleuropaischen Eichengallen," _Verhandl. d. zoolog.-bot. Ges. in Wien_, xxii. pp. 669-726; and "Die europaischen Torymiden," _ib._ xxiv. pp. 53-142 (abstracted in _Cistula entomologica_, i., London, 1869-1876); F. Low, "Beitrage zur Kenntnis der Gallmucken," _ib._ pp. 143-162, and 321-328; J.E. von Bergenstamm and P. Low, "Synopsis Cecidomyidarum," _ib._ xxvi. pp. 1-104; Perris, _Ann. Soc. Entom. de France_, 4th ser. vol. x. pp. 176-185; R. Osten-Sacken, "On the North American Cecidomyidae," _Smithsonian Miscellaneous Collections_, vol. vi. (1867), p. 173; E.L. Taschenberg, _Entomologie fur Gartner und Gartenfreunde_ (Leipzig, 1871); J.W.H. Traill, "Scottish Galls," _Scottish Naturalist_, i. (1871), pp. 123, &c.; Albert Muller, "British Gall Insects," _The Entomologist's Annual for 1872_, pp. 1-22; B. Altum, _Forstzoologie_, iii. "Insecten," pp. 250 seq. (Berlin, 1874); J.H. Kaltenbach, _Die Pflanzenfeinde aus der Classe der Insecten_ (Stuttgart, 1874); A. d'Arbois de Jubainville and J. Vesque, _Les Maladies des plantes cultivees_, pp. 98-105 (Paris, 1878). (F. H. B.)

FOOTNOTES:

[1] Quoted in _Zoological Record_, iv. (1867), p. 192.

[2] P. Cameron, _Scottish Naturalist_, ii. pp. 11-15.

[3] _Entomologist_, vii. p. 47.

[4] See in _Proc. Entom. Soc. of London for the Year 1873_, p. xvi.

[5] See A. Muller, _Gardener's Chronicle_ (1871), pp. 1162 and 1518; and E.A. Fitch, _Entomologist_, xi. p. 129.

[6] _Entomologist_, vi. pp. 275-278, 339-340.

[7] _Verhandl. d. zoolog.-bot. Ges. in Wien_, xxi. p. 799.

[8] Darwin, _Variations of Animals and Plants under Domestication_, ii. p. 282.

[9] "Recherches pour servir a l'histoire des galles," _Ann. des sci. nat._ xix. pp. 293 sqq.

[10] According to Dr Adler, alternation of generations takes place between _N. lenticularis_ and _Spathegaster baccarum_ (see E.A. Ormerod, _Entomologist_, xi. p. 34).

[11] See Westwood, _Introd. to the Mod. Classif. of Insects_, ii. (1840) p. 130.

[12] For figures and descriptions of insect and gall, see _Entomologist_, iv. p. 17, vii. p. 241, ix. p. 53, xi. p. 131.

[13] _Scottish Naturalist_, i. (1871) p. 116, &c.

[14] Vinen, _Journ. de pharm. et de chim._ xxx. (1856) p. 290; "English Ink-Galls," _Pharm. Journ._ 2nd ser. iv. p. 520.

[15] See Pereira, _Materia Medica_, vol. ii. pt. i. p. 347; _Pharm. Journ._ 1st ser. vol. viii. pp. 422-424.

[16] See R.H. Stretch and C.D. Gibbes, _Proc. California Acad. of Sciences_, iv. pp. 265 and 266.

[17] _A Complete History of Drugs_ (translation), p. 169 (London, 1748).

[18] F. Porter Smith, _Contrib. towards the Mat. Medica ... of China_, p. 100 (1871).

[19] R.F. Burton, _First Footsteps in E. Africa_, p. 178 (1856).

[20] A.S. Packard, jun., _Guide to the Study of Insects_, p. 205 (Salem, 1870).

[21] On the Cecidomyids of _Quercus Cerris_, see Fitch, _Entomologist_, xi. p. 14.

[22] See, on _Cecidomyia oenephila_, Von Haimhoffen, _Verhandl. d. zoolog.-bot. Ges. in Wien_, xxv. pp. 801-810.

[23] See _Entomologist's Month. Mag._ iv. (1868) p. 233; and for figure and description, _Entomologist_, xi. p. 13.

[24] A.S. Packard, jun., _Our Common Insects_, p. 203 (Salem, U.S. 1873). On the Hessian fly, _Cecidomyia destructor_, Say, the May brood of which produces swellings immediately above the joints of barley attacked by it, see Asa Fitch, _The Hessian Fly_ (Albany, 1847), reprinted from _Trans. New York State Agric. Soc._ vol. vi.

[25] J. Winnertz, _Beitrag zu einer Monographie der Sciarinen_, p. 164 (Vienna, 1867).

[26] Asa Fitch, _First and Second Rep. on the Noxious ... Insects of the State of New York_, p. 167 (Albany, 1856).

[27] See E. Doubleday, _Pharm. Journ._ 1st ser, vol. vii. p. 310: and Pereira, _ib._ vol. iii. p. 377.

[28] _Dingler's Polyt. Journ._ ccxvi. p. 453.

[29] For figure and description see _Zoology of the "Erebus" and "Terror,"_ ii. pp. 46, 47 (1844-1875).

[30] On the mite-galls and their makers, see F. Low, "Beitrage zur Naturgesch. der Gallmilben (_Phytoptus_, Duj.)," _Verhandl. d. zoolog.-bot. Ges. in Wien_, xxiv. (1874), pp. 2-16, with plate; and "Uber Milbengallen (Acarocecidien) der Wiener-Gegend," _ib._ pp. 495-508; Andrew Murray, _Economic Entomology, Aptera_, pp. 331-374 (1876); and F.A.W. Thomas, _Altere und neue Beobachtungen uber Phytopto-Cecidien_ (Halle, 1877).

GALLUPPI, PASQUALE (1770-1846), Italian philosopher, was born on the 2nd of April 1770 at Tropea, in Calabria. He was of good family, and after studying at the university of Naples he entered the public service, and was for many years employed in the office of the administration of finances. At the age of sixty, having become widely known by his writings on philosophy, he was called to the chair of logic and metaphysics in the university of Naples, which he held till his death in November 1846. His most important works are: _Lettere filosofiche_ (1827), in which he traces his philosophical development; _Elementi di filosofia_ (1832); _Saggio filosofico sulla critica della conoscenza_ (1819-1832); _Sull' analisi e sulla sintesi_ (1807); _Lezioni di logica e di metafisica_ (1832-1836); _Filosofia della volonta_ (1832-1842, incomplete); _Storia della filosofia_ (i., 1842); _Considerazioni filosofiche sull' idealismo trascendentale_ (1841), a memoir on the system of Fichte.

On his philosophical views see L. Ferri, _Essai sur l'histoire de la philosophie en Italie au XIX^e siecle_, i. (1869); V. Botta in Ueberweg's _Hist. of Philosophy_, ii. app. 2; G. Barzellotti, "Philosophy in Italy," in Mind, iii. (1878); V. Lastrucci, _Pasquale Galluppi. Studio critico_ (Florence, 1890).

GALLUS, CORNELIUS (c. 70-26 B.C.), Roman poet, orator and politician, was born of humble parents at Forum Julii (_Frejus_) in Gaul. At an early age he removed to Rome, where he was taught by the same master as Virgil and Varius Rufus. Virgil, who dedicated one of his eclogues (x.) to him, was in great measure indebted to the influence of Gallus for the restoration of his estate. In political life Gallus espoused the cause of Octavianus, and as a reward for his services was made praefect of Egypt (Suetonius, _Augustus_, 66). His conduct in this position afterwards brought him into disgrace with the emperor, and having been deprived of his estates and sentenced to banishment, he put an end to his life (Dio Cassius liii. 23). Gallus enjoyed a high reputation among his contemporaries as a man of intellect, and Ovid (_Tristia_, iv. 10) considered him the first of the elegiac poets of Rome. He wrote four books of elegies chiefly on his mistress Lycoris (a poetical name for Cytheris, a notorious actress), in which he took for his model Euphorion of Chalcis (q.v.); he also translated some of this author's works into Latin. Nothing by him has survived; the fragments of the four poems attributed to him (first published by Aldus Manutius in 1590 and printed in A. Riese's _Anthologia Latina_, 1869) are generally regarded as a forgery.

See C. Volker, _De C. Galli vita et scriptis_ (1840-1844); A. Nicolas, _De la vie et des ouvrages de C. Gallus_ (1851), an exhaustive monograph. An inscription found at Philae (published 1896) records the Egyptian exploits; see M. Schanz, _Geschichte der romischen Litteratur_, and Plessis, _Poesie latine_ (1909).

GALLUS, GAIUS AELIUS, praefect of Egypt 26-24 B.C. By order of Augustus he undertook an expedition to Arabia Felix, with disastrous results. The troops suffered greatly from disease, heat, want of water and the obstinate resistance of the inhabitants. The treachery of a foreign guide also added to his difficulties. After six months Gallus was obliged to return to Alexandria, having lost the greater part of his force. He was a friend of the geographer Strabo, who gives an account of the expedition (xvi. pp. 780-782; see also Dio Cassius liii. 29; Pliny, _Nat. Hist._ vi. 32; C. Merivale, _Hist. of the Romans under the Empire_, ch. 34; H. Kruger, _Der Feldzug des A. G. nach dem glucklichen Arabien_, 1862). He has been identified with the Aelius Gallus frequently quoted by Galen, whose remedies are stated to have been used with success in an Arabian expedition.

GALLUS, GAIUS CESTIUS, governor of Syria during the reign of Nero. When the Jews in Jerusalem, stirred to revolt by the outrages of the Roman procurators, had seized the fortress of Masada and treacherously murdered the garrison of the palace of Herod, Gallus set out from Antioch to restore order. On the 17th of November A.D. 66 he arrived before Jerusalem. Having gained possession of the northern suburb, he attacked the temple mount; but, after five days' fighting, just when (according to Josephus) success was within his grasp, he unaccountably withdrew his forces. During his retreat he was closely pursued by the Jews and surrounded in a ravine, and only succeeded in making good his escape to Antioch by sacrificing the greater part of his army and a large amount of war material. Soon after his return Gallus died (before the spring of 67), and was succeeded in the governorship by Licinius Mucianus, the prosecution of the war being entrusted to Vespasian.

See Tacitus, _Hist._ v. 10, 13; Suetonius, _Vespasian_, 4; Josephus, _Bell. Jud._ ii. 14-20; E. Schurer, _Hist. of the Jewish People_, div. i. vol. ii. p. 212 (Eng. tr., 1890).

GALLUS, GAIUS SULPICIUS, Roman general, statesman and orator. Under Lucius Aemilius Paulus, his intimate friend, he commanded the 2nd legion in the campaign against Perseus, king of Macedonia, and gained great reputation for having predicted an eclipse of the moon on the night before the battle of Pydna (168 B.C.). On his return from Macedonia he was elected consul (166), and in the same year reduced the Ligurians to submission. In 164 he was sent as ambassador to Greece and Asia, where he held a meeting at Sardis to investigate the charges brought against Eumenes of Pergamum by the representatives of various cities of Asia Minor. Gallus was a man of great learning, an excellent Greek scholar, and in his later years devoted himself to the study of astronomy, on which subject he is quoted as an authority by Pliny.

See Livy xliv. 37, _Epit_. 46; Polybius xxxi. 9, 10; Cicero, _Brutus_, 20, _De officiis_, i. 6, _De senectute_, 14; Pliny, _Nat. Hist._ ii. 9.

GALOIS, EVARISTE (1811-1832), French mathematician, was born on the 25th of October 1811, and killed in a duel on the 31st of May 1832. An obituary notice by his friend Auguste Chevalier appeared in the _Revue encyclopedique_ (1832); and his collected works are published, _Journal de Liouville_ (1846), pp. 381-444, about fifty of these pages being occupied by researches on the resolubility of algebraic equations by radicals. This branch of algebra he notably enriched, and to him is also due the notion of a group of substitutions (see EQUATION: _Theory of Equations_; also GROUPS, THEORY OF).

His collected works, with an introduction by C.F. Picard, were published in 1897 at Paris.

GALSTON, a police burgh and manufacturing town of Ayrshire, Scotland. Pop. (1901) 4876. It is situated on the Irvine, 5 m. E. by S. of Kilmarnock, with a station on the Glasgow & South-Western railway. The manufactures include blankets, lace, muslin, hosiery and paper-millboard, and coal is worked in the vicinity. About 1 m. to the north, amid the "bonnie woods and braes," is Loudoun Castle, a seat of the earl of Loudoun.

GALT, SIR ALEXANDER TILLOCH (1817-1893), Canadian statesman, was the youngest son of John Galt the author. Born in London on the 6th of September 1817, he emigrated to Canada in 1835, and settled in Sherbrooke, in the province of Quebec, where he entered the service of the British American Land Company, of which he rose to be chief commissioner. Later he was one of the contractors for extending the Grand Trunk railway westward from Toronto. He entered public life in 1849 as Liberal member for the county of Sherbrooke, but opposed the chief measure of his party, the Rebellion Losses Bill, and in the same year signed a manifesto in favour of union with the United States, believing that in no other way could Protestant and Anglo-Saxon ascendancy over the Roman Catholic French majority in his native province be maintained. In the same year he retired from parliament but re-entered it in 1853, and was till 1872 the chief representative of the English-speaking Protestants of Quebec province. On the fall of the Brown-Dorion administration in 1858 he was called on to form a ministry, but declined the task, and became finance minister under Sir John Macdonald and Sir George Cartier on condition that the federation of the British North American provinces should become a part of their programme. From 1858 to 1862 and 1864 to 1867 he was finance minister, and did much to reduce the somewhat chaotic finances of Canada into order. To him are due the introduction of the decimal system of currency and the adoption of a system of protection to Canadian manufactures. To his diplomacy was due the coalition in 1864 between Macdonald, Brown and Cartier, which carried the federation of the British North American provinces, and throughout the three years of negotiation which followed his was one of the chief influences. He became finance minister in the first Dominion ministry, but suddenly and mysteriously resigned on the 4th of November 1867. After his retirement he gave to the administration of Sir John Macdonald a support which grew more and more fitful, and advocated independence as the final destiny of Canada. In 1871 he was again offered the ministry of finance on condition of abandoning these views, but declined. In 1877 he was the Canadian nominee on the Anglo-American fisheries commission at Halifax, and rendered brilliant service. In 1880 he was appointed Canadian high commissioner to Great Britain, but retired in 1883 in favour of Sir Charles Tupper. During this period he advocated imperial federation. He was Canadian delegate at the Paris Monetary Conference of 1881, and to the International Exhibition of Fisheries in 1883. From this date till his death on the 19th of September 1893 he lived in retirement. No Canadian statesman has had sounder or more abundant ideas, but a certain intellectual fickleness made him always a somewhat untrustworthy colleague in political life. (W. L. G.)

GALT, JOHN (1779-1839), Scottish novelist, was born at Irvine, Ayrshire, on the 2nd of May 1779. He received his early education at Irvine and Greenock, and read largely from one of the public libraries while serving as a clerk in a mercantile office. In 1804 he went to settle in London, where he published anonymously a poem on the _Battle of Largs_. After unsuccessful attempts to succeed in business Galt entered at Lincoln's Inn, but was never called to the bar. He obtained a commission from a British firm to go abroad to find out whether the Berlin and Milan decrees could be evaded. He met Byron and Sir John Hobhouse at Gibraltar, travelled with Byron to Malta, and met him again at Athens. He was afterwards employed by the Glasgow merchant Kirkman Finlay on similar business at Gibraltar, and in 1814 visited France and Holland. His early works are the _Life and Administration of Wolsey_, _Voyages and Travels_, _Letters from the Levant_, the _Life of Benjamin West_, _Historical Pictures_ and _The Wandering Jew_; and he induced Colburn to publish a periodical containing dramatic pieces rejected by London managers. These were afterwards edited by Galt as the _New British Theatre_, which included some plays of his own. He first showed his real power as a writer of fiction in _The Ayrshire Legatees_, which appeared in _Blackwood's Magazine_ in 1820. This was followed in 1821 by his masterpiece--_The Annals of the Parish_; and, at short intervals, _Sir Andrew Wylie_, _The Entail_, _The Steam-Boat_ and _The Provost_ were published. These humorous studies of Scottish character are all in his happiest manner. His next works were _Ringan Gilhaize_ (1823), a story of the Covenanters; _The Spaewife_ (1823), which relates to the times of James I. of Scotland; _Rothelan_ (1824), a novel founded on the reign of Edward III.; _The Omen_ (1825), which was favourably criticized by Sir Walter Scott; and _The Last of the Lairds_, another picture of Scottish life.

In 1826 he went to America as secretary to the Canada Land Company. He carried out extensive schemes of colonization, and opened up a road through what was then forest country between Lakes Huron and Erie. In 1827 he founded Guelph in upper Canada, passing on his way the township of Galt on the Grand river, named after him by the Hon. William Dixon. But all this work proved financially unprofitable to Galt. In 1829 he returned to England commercially a ruined man, and devoted himself with great ardour to literary pursuits, of which the first fruit was _Lawrie Todd_--one of his best novels. Then came _Southennan_, a tale of Scottish life in the times of Queen Mary. In 1830 he was appointed editor of the _Courier_ newspaper--a post he soon relinquished. His untiring industry was seen in the publication, in rapid succession, of a _Life of Byron_, _Lives of the Players_, _Bogle Corbet_, _Stanley Buxton_, _The Member_, _The Radical_, _Eben Erskine_, _The Stolen Child_, his _Autobiography_, and a collection of tales entitled _Stories of the Study_. In 1834 appeared his _Literary Life and Miscellanies_, dedicated by permission to William IV., who sent the author a present of L200. As soon as this work was published Galt retired to Greenock, where he continued his literary labours till his death on the 11th of April 1839.

Galt, like almost all voluminous writers, was exceedingly unequal. His masterpieces are _The Ayrshire Legatees_, _The Annals of the Parish_, _Sir Andrew Wylie_, _The Entail_, _The Provost_ and _Lawrie Todd_. _The Ayrshire Legatees_ gives, in the form of a number of exceedingly diverting letters, the adventures of the Rev. Dr Pringle and his family in London. The letters are made the excuse for endless tea-parties and meetings of kirk-session in the rural parish of Garnock. _The Annals of the Parish_ are told by the Rev. Micah Balwhidder, Galt's finest character. This work (which, be it remembered, existed in MS. before _Waverley_ was published) is a splendid picture of the old-fashioned Scottish pastor and the life of a country parish; and, in rich humour, genuine pathos and truth to nature it is unsurpassed even by Scott. It is a fine specimen of the homely graces of the Scottish dialect, and preserves much vigorous Doric phraseology fast passing out of use even in country districts. In this novel Mr Galt used, for the first time, the term "Utilitarian," which afterwards became so intimately associated with the doctrines of John Stuart Mill and Bentham (see _Annals of the Parish_, chap. xxxv., and a note by Mill in _Utilitarianism_, chap. ii.). In _Sir Andrew Wylie_ the hero entered London as a poor lad, but achieved remarkable success by his shrewd business qualities. The character is somewhat exaggerated, but excessively amusing. _The Entail_ was read thrice by Byron and Scott, and is the best of Galt's longer novels. Leddy Grippy is a wonderful creation, and was considered by Byron equal to any female character in literature since Shakespeare's time. _The Provost_, in which Provost Pawkie tells his own story, portrays inimitably the jobbery, bickerings and self-seeking of municipal dignitaries in a quaint Scottish burgh. In _Lawrie Todd_ Galt, by giving us the Scot in America, accomplished a feat which Sir Walter never attempted. This novel exhibits more variety of style and a greater love of nature than his other books. The life of a settler is depicted with unerring pencil, and with an enthusiasm and imaginative power much more poetical than any of the author's professed poems.

The best of Galt's novels were reprinted in Blackwood's _Standard Novels_, to volume i. of which his friend Dr Moir prefixed a memoir.

GALT, a town in Waterloo county, Ontario, Canada, 23 m. N.N.W. of Hamilton, on the Grand river and on the Grand Trunk and Canadian Pacific railways. Pop. (1881) 5187; (1901) 7866. It is named after John Galt, the author. It has excellent water privileges which furnish power for flour-mills and for manufactures of edge tools, castings, machinery, paper and other industries.

GALTON, SIR FRANCIS (1822- ), English anthropologist, son of S.T. Galton, of Duddeston, Warwickshire, was born on the 16th of February 1822. His grandfather was the poet-naturalist Erasmus Darwin, and Charles Darwin was his cousin. After attending King Edward VI.'s grammar school, Birmingham, he studied at Birmingham hospital, and afterwards at King's College, London, with the intention of making medicine his profession; but after taking his degree at Trinity College, Cambridge, in 1843 he changed his mind. The years 1845-1846 he spent in travelling in the Sudan, and in 1850 he made an exploration, with Dr John Anderson, of Damaraland and the Ovampo country in south-west Africa, starting from Walfisch Bay. These tracts had practically never been traversed before, and on the appearance of the published account of his journey and experiences under the title of _Narrative of an Explorer in Tropical South Africa_ (1853) Galton was awarded the gold medal of the Royal Geographical Society. His _Art of Travel; or, Shifts and Contrivances in Wild Countries_ was first published in 1855. In 1860 he visited the north of Spain, and published the fruits of his observations of the country and the people in the first of a series of volumes, which he edited, entitled _Vacation Tourists_. He then turned to meteorology, the result of his investigations appearing in _Meteorographica_, published in 1863. This work was the first serious attempt to chart the weather on an extensive scale, and in it also the author first established the existence and theory of anti-cyclones. Galton was a member of the meteorological committee (1868), and of the Meteorological Council which succeeded it, for over thirty years. But his name is most closely associated with studies in anthropology and especially in heredity. In 1869 appeared his _Hereditary Genius, its Laws and Consequences_, a work which excited much interest in scientific and medical circles. This was followed by _English Men of Science, their Nature and Nurture_, published in 1874; _Inquiries into Human Faculty and its Development_, issued in 1883; _Life-History Album_ (1884); _Record of Family Faculties_ (1884) (tabular forms and directions for entering data, with a preface); and _Natural Inheritance_ (1889). The idea that systematic efforts should be made to improve the breed of mankind by checking the birth-rate of the unfit and furthering the productivity of the fit was first put forward by him In 1865; he mooted it again in 1884, using the term "eugenics" for the first time in _Human Faculty_, and in 1904 he endowed a research fellowship in the university of London for the promotion of knowledge of that subject, which was defined as "the study of agencies under social control that may improve or impair the racial qualities of future generations, either physically or mentally." Galton was the author of memoirs on various anthropometric subjects; he originated the process of composite portraiture, and paid much attention to finger-prints and their employment for the identification of criminals, his publications on this subject including _Finger Prints_ (1892), _Decipherment of Blurred Finger Prints_ (1893) and _Finger Print Directories_ (1895). From the Royal Society, of which he was elected a fellow in 1860, he received a royal medal in 1886 and the Darwin medal in 1902, and honorary degrees were bestowed on him by Oxford (1894) and Cambridge (1895). In 1908 he published _Memories of My Life_, and in 1909 he received a knighthood.

GALUPPI, BALDASSARE (1706-1785), Italian musical composer, was born on the 18th of October 1706 on the island of Burano near Venice, from which he was often known by the nickname of Buranello. His father, a barber, and violinist at the local theatre, was his first teacher. His first opera, composed at the age of sixteen, being hissed off the stage, he determined to study seriously, and entered the Conservatorio degli Incurabili at Venice, as a pupil of Antonio Lotti. After successfully producing two operas in collaboration with a fellow-pupil, G.B. Pescetti, in 1728 and 1729, he entered upon a busy career as a composer of operas for Venetian theatres, writing sometimes as many as five in a year. He visited London in 1741, and arranged a _pasticcio_, _Alexander in Persia_, for the Haymarket. Burney considered his influence on English music to have been very powerful. In 1740 he became _vice-maestro di cappella_ at St Mark's and _maestro_ in 1762. In 1749 he began writing comic operas to libretti by Goldoni, which enjoyed an enormous popularity. He was invited to Russia by Catherine II. in 1766, where his operas made a favourable impression, and his influence was also felt in Russian church music. He returned to Venice in 1768, where he had held the post of director of the Conservatorio degli Incurabili since 1762. He died on the 3rd of January 1785.

Galuppi's best works are his comic operas, of which _Il Filosofo di Campagna_ (1754), known in England as _The Guardian Trick'd_ (Dublin, 1762) was the most popular. His melody is attractive rather than original, but his workmanship in harmony and orchestration is generally superior to that of his contemporaries. He seems to have been the first to extend the concerted finales of Leo and Logroscino into a chain of several separate movements, working up to a climax, but in this respect he is much inferior to Sarti and Mozart.

Browning's poem, "A Toccata of Galuppi," does not refer to any known composition, but more probably to an imaginary extemporization on the harpsichord, such as was of frequent occurrence in the musical gatherings of Galuppi's day.

See also Alfred Wotquerme, _Baldassare Galuppi, etude bibliographique sur ses oeuvres dramatiques_ (Brussels, 1902). Many of his autograph scores are in the library of the Brussels conservatoire. (E. J. D.)

GALVANI, LUIGI (1737-1798), Italian physiologist, after whom galvanism received its name, was born at Bologna on the 9th of September 1737. It was his wish in early life to enter the church, but by his parents he was educated for a medical career. At the university of Bologna, in which city he practised, he was in 1762 appointed public lecturer in anatomy, and soon gained repute as a skilled though not eloquent teacher, and, chiefly from his researches on the organs of hearing and genito-urinary tract of birds, as a comparative anatomist. His celebrated theory of animal electricity he enunciated in a treatise, "De viribus electricitatis in motu musculari commentarius," published in the 7th volume of the memoirs of the Institute of Sciences at Bologna in 1791, and separately at Modena in the following year, and elsewhere subsequently. The statement has frequently been repeated that, in 1786, Galvani had noticed that the leg of a skinned frog, on being accidentally touched by a scalpel which had lain near an electrical machine, was thrown into violent convulsions; and that it was thus that his attention was first directed to the relations of animal functions to electricity. From documents in the possession of the Institute of Bologna, however, it appears that twenty years previous to the publication of his _Commentary_ Galvani was already engaged in investigations as to the action of electricity upon the muscles of frogs. The observation that the suspension of certain of these animals on an iron railing by copper hooks caused twitching in the muscles of their legs led him to the invention of his metallic arc, the first experiment with which is described in the third part of the _Commentary_, with the date September 20, 1786. The arc he constructed of two different metals, which, placed in contact the one with a frog's nerve and the other with a muscle, caused contraction of the latter. In Galvani's view the motions of the muscle were the result of the union, by means of the metallic arc, of its exterior or negative electrical charge with positive electricity which proceeded along the nerve from its inner substance. Volta, on the other hand, attributed them solely to the effect of electricity having its source in the junction of the two dissimilar metals of the arc, and regarded the nerve and muscle simply as conductors. On Galvani's refusal, from religious scruples, to take the oath of allegiance to the Cisalpine republic in 1797, he was removed from his professorship. Deprived thus of the means of livelihood, he retired to the house of his brother Giacomo, where he soon fell into a feverish decline. The republican government, in consideration of his great scientific fame, eventually, but too late, determined to reinstate him in his chair, and he died at Bologna on the 4th of December 1798.

A quarto edition of his works was published at Bologna in 1841-1842, by the Academy of Sciences of the Institute of that city, under the title _Opere edite ed inedite del professore Luigi Galvani_.

GALVANIZED IRON, sheet iron having its surface covered with a thin coating of zinc. In spite of the name, galvanic action has often no part in the production of galvanized iron, which is prepared by dipping the iron, properly cleaned and pickled in acid, in a bath of molten zinc. The hotter the zinc the thinner the coating, but as a high temperature of the bath is attended with certain objections, it is a common practice to use a moderate temperature and clear off the excess of zinc by passing the plates between rollers. In Norwood and Rogers's process a thin coating of tin is applied to the iron before it is dipped in the zinc, by putting the plates between layers of granulated tin in a wooden tank containing a dilute solution of stannous chloride, when tin is deposited on them by galvanic action. In "cold galvanizing" the zinc is deposited electrolytically from a bath, preferably kept neutral or slightly acid, containing a 10% solution of crystallized zinc sulphate, ZnSO4.7H2O. The resulting surface is usually duller and less lustrous than that obtained by the use of molten zinc. Another method of forming a coating of zinc, known as "sherardizing," was invented by Sherard Cowper-Coles, who found that metals embedded in zinc dust (a product obtained in zinc manufacture and consisting of metallic zinc mixed with a certain amount of zinc oxide) and heated to temperatures well below the melting point of zinc, become coated with a layer of that metal. In carrying out the process the articles are placed in an air-tight vessel with the zinc dust, which must be dry, and subjected to a heat of 250-330 deg. C., the time for which the heating is continued depending on the thickness of the deposit required and varying from one-half to several hours. If an air-tight receptacle is not available, a small percentage of powdered carbon is added to the zinc-dust, to prevent increase in the amount of oxide, which, if present in excess, tends to make the deposit dull.

Galvanized iron by its zinc surface is protected from corrosion by the weather, though the protection is not very efficient in the presence of acid or sulphurous fumes, and accordingly it is extensively employed for roofing, especially in the form of corrugated sheets. The iron wire used for wire-netting, telegraphic purposes, &c., is commonly galvanized, as also are bolts, nuts, chains and other fittings on ships.

GALVANOMETER, an instrument for detecting or measuring electric currents. The term is generally applied to instruments which indicate electric current in scale divisions or arbitrary units, as opposed to instruments called amperemeters (q.v.), which show directly on a dial the value of the current in amperes. Galvanometers may be divided into direct current and alternating current instruments, according as they are intended to measure one or other of these two classes of currents (see ELECTROKINETICS).

_Direct Current Galvanometers_.--The principle on which one type of direct current galvanometer, called a movable needle galvanometer, depends for its action is that a small magnet when suspended in the centre of a coil of wire tends to set its magnetic axis in the direction of the magnetic field of the coil at that point due to the current passing through it. In the other type, or movable coil galvanometer, the coil is suspended and the magnet fixed; hence the coil tends to set itself with its axis parallel to the lines of force of the magnet. The movable system must be constrained in some way to take up and retain a definite position when no current is passing by means which are called the "control."

Movable needle galvanometer.

Mirror galvanometers.

In its simple and original form the movable needle galvanometer consisted of a horizontal magnetic needle suspended within a coil of insulated wire by silk fibres or pivoted on a point like a compass needle. The direction of such a needle is controlled by the direction of the terrestrial magnetic force within the coil. If the needle is so placed that its axis is parallel to the plane of the coil, then when an electric current passes through the coil it is deflected and places itself at an angle to the axis of the coil determined by the strength of the current and of the controlling field. In the early forms of movable needle galvanometer the needle was either a comparatively large magnet several inches in length, or else a smaller magnet was employed carrying a long pointer which moved over a scale of degrees so as to indicate the deflexion. A method of measuring the deflexion by means of a mirror scale and telescope was introduced by K.F. Gauss and W. Weber. The magnet had a mirror attached to it, and a telescope having cross wires in the focus was used to observe the scale divisions of a fixed scale seen reflected in the mirror. Lord Kelvin (Professor W. Thomson) made the important improvement of reducing the size of the needle and attaching it to the back of a very small mirror, the two being suspended by a single fibre of cocoon silk. The mirror was made of silvered microscopic glass about 1/4 in. in diameter, and the magnetic needle or needles consisted of short fragments of watchspring cemented to its back. A ray of light being thrown on the mirror from a lamp the deflexions of the needle were observed by watching the movements of a spot of light reflected from it upon a fixed scale. This form of mirror galvanometer was first devised in connexion with submarine cable signalling, but soon became an indispensable instrument in the physical laboratory.

Astatic galvanometers.

In course of time both the original form of single needle galvanometer and mirror galvanometer were improved by introducing the astatic principle and weakening the external controlling magnetic field. If two magnetic needles of equal size and moment are attached rigidly to one stem parallel to each other but with poles placed in opposite directions an astatic system results; that is, if the needles are so suspended as to be free to move in a horizontal plane, and if they are made exactly equal in magnetic strength, the system will have no directive power. If one needle is slightly weaker than the other, the suspended system will set itself with some axis parallel to the lines of force of a field in which it is placed. In a form of astatic needle galvanometer devised by Professor A. Broca of Paris, the pair of magnetized needles are suspended vertically and parallel to each other with poles in opposite directions. The upper poles are included in one coil and the lower poles within another coil, so connected that the current circulates in the right direction in each coil to displace the pairs of poles in the same direction. By this mode of arrangement a greater magnetic moment can be secured, together with more perfect astaticity and freedom from disturbance by external fields. The earth's magnetic field can be weakened by means of a controlling magnet arranged to create in the space in the interior of the galvanometer coils an extremely feeble controlling magnetic field. In instruments having a coil for each needle and designed so that the current in both coils passes so as to turn both needles in the same direction, the controlling magnet is so adjusted that the normal position of the needles is with the magnetic axis parallel to the plane of the coil. An astatic magnetic system used in conjunction with a mirror galvanometer gives a highly sensitive form of instrument (fig. 1); it is, however, easily disturbed by stray magnetic fields caused by neighbouring magnets or currents through conductors, and therefore is not suitable for use in many places.

Movable coil galvanometer.

This fact led to the introduction of the movable coil galvanometer which was first devised by Lord Kelvin as a telegraphic signalling instrument but subsequently modified by A. d'Arsonval and others into a laboratory galvanometer (fig. 2). In this instrument a permanent magnet, generally of the horseshoe shape, is employed to create a strong magnetic field, in which a light movable coil is suspended. The suspension is bifilar, consisting of two fine wires which are connected to the ends of the coil and serve to lead the current in and out. If such a coil is placed with its plane parallel to the lines of force of the permanent magnet, then when a current is passing through it it displaces itself in the field, so as to set with its axis more nearly parallel to the lines of force of the field. The movable coil may carry a pointer or a mirror; in the latter form it is well represented by several much used laboratory instruments. The movable coil galvanometer has the great advantage that it is not easily disturbed by the magnetic fields caused by neighbouring magnets or electric currents, and thus is especially useful in the electrical workshop and factory.

[Illustration: FIG. 1.--Kelvin Astatic Mirror Galvanometer. Elliott square pattern.]

[Illustration: FIG. 2.--Movable Coil Galvanometer.]

Construction and use.

In the practical construction of the suspended needle fixed coil galvanometer great care must be taken with the insulation of the wire of the coil. This wire is generally silk-covered, wound on a frame, the whole being thoroughly saturated with paraffin wax. In some cases two wires are wound on in parallel, constituting a "differential galvanometer." When properly adjusted this instrument can be used for the exact comparison of electric currents by a null method, because if an electric current is passed through one wire and creates certain deflexions of the needle, the current which annuls this deflexion when passed through the other wire must be equal to the first current. In the construction of a movable coil galvanometer, it is usual to intensify the magnetic field by inserting a fixed soft iron core in the interior of the movable coil. If the current to be measured is too large to be passed entirely through the galvanometer, a portion is allowed to flow through a circuit connecting the two terminals of the instrument. This circuit is called a _shunt_ and is generally arranged so as to take 0.9, 0.99, or 0.999 of the total current, leaving 0.1, 0.01 or 0.001 to flow through the galvanometer. W.E. Ayrton and T. Mather have designed a universal shunt box or resistance which can be applied to any galvanometer and by which a known fraction of any current can be sent through the galvanometer when we know its resistance (see _Jour. Inst. Elec. Eng. Lond_., 1894, 23, p. 314). A galvanometer can be calibrated, or the meaning of its deflexion determined, by passing through it an electric current of known value and observing the deflexion of the needle or coil. The known current can be provided in the following manner:--a single secondary cell of any kind can have its electromotive force measured by the potentiometer (q.v.), and compared with that of a standard voltaic cell. If the secondary cell is connected with the galvanometer through a known high resistance R, and if the galvanometer is shunted, that is, has its terminals connected by another resistance S, then if the resistance of the galvanometer itself is denoted by G, the whole resistance of the shunted galvanometer and high resistance has a value represented by R + GS/(G + S), and therefore the current through the galvanometer produced by an electromotive force E of the cell is represented by

SE -------------. R(G + S) + GS

Suppose this current produces a deflexion of the needle or coil or spot of light equal to X scale divisions, we can then alter the value of the resistances R and S, and so determine the relation between the deflexion and the current. By the sensitiveness of the galvanometer is meant the deflexion produced by a known electromotive force put upon its terminals or a known current sent through it. It is usual to specify the sensitiveness of a mirror galvanometer by requiring a certain deflexion, measured in millimetres, of a spot of light thrown on the scale placed at one metre from the mirror, when an electromotive force of one-millionth of a volt (microvolt) is applied to the terminals of the galvanometer; it may be otherwise expressed by stating the deflexion produced under the same conditions when a current of one microampere is passed through the coil. In modern mirror galvanometers a deflexion of 1 mm. of the spot of light upon a scale at 1 metre distance can be produced by a current as small as one hundred millionth (10^-8) or even one ten thousand millionth (10^-10) of an ampere. It is easy to produce considerable sensitiveness in the galvanometer, but for practical purposes it must always be controlled by the condition that the zero remains fixed, that is to say, the galvanometer needle or coil must come back to exactly the same position when no current is passing through the instrument. Other important qualifications of a galvanometer are its time-period and its dead-beatness. For certain purposes the needle or coil should return as quickly as possible to the zero position and with either no, or very few, oscillations. If the latter condition is fulfilled the galvanometer is said to be "dead-beat." On the other hand, for some purposes the galvanometer is required with the opposite quality, that is to say, there must be as little retardation as possible to the needle or coil when set in motion under an impulsive blow. Such a galvanometer is called "ballistic." The quality of a galvanometer in this respect is best estimated by taking the logarithmic decrement of the oscillations when the movable system is set swinging. This last term is defined as the logarithm of the ratio of one swing to the next succeeding swing, and a galvanometer of which the logarithmic decrement is large, is said to be highly damped. For many purposes, such as for resistance measurement, it is desirable to have a galvanometer which is highly damped; this result can be obtained by affixing to the needles either light pieces of mica, when it is a movable needle galvanometer, or by winding the coil on a silver frame when it is a movable coil galvanometer. On the other hand, for the comparison of capacities of condensers and for other purposes, a galvanometer is required which is as little damped as possible, and for this purpose the coil must have the smallest possible frictional resistance to its motion through the air. In this case the moment of inertia of the movable system must be decreased or the control strengthened.

The Einthoven string galvanometer is another form of sensitive instrument for the measurement of small direct currents. It consists of a fine wire or silvered quartz fibre stretched in a strong magnetic field. When a current passes through the wire it is displaced across the field and the displacement is observed with a microscope.

Tangent galvanometer.

For the measurement of large currents a "tangent galvanometer" is employed (fig. 3). Two fixed circular coils are placed apart at a distance equal to the radius of either coil, so that a current passing through them creates in the central region between them a nearly uniform magnetic field. At the centre of the coils is suspended a small magnetic needle the length of which should not be greater than 1/10 the radius of either coil. The normal position of the needle is at right angles to the line joining the centre of the coils. If a current is passed through the coils, the needle will be deflected, and the tangent of the angle of its deflexion will be nearly proportional to the current passing through the coil, provided that the controlling field is uniform in strength and direction, and that the length of the magnetic needle is so short that the space in which it rotates is a practically uniform magnetic field.

[Illustration: FIG. 3.--Helmholtz Tangent Galvanometer.]

_Alternating Current Galvanometers._--For the detection of small alternating currents a magnetic needle or movable coil galvanometer is of no utility. We can, however, construct an instrument suitable for the purpose by suspending within a coil of insulated wire a small needle of soft iron placed with its axis at an angle of 45 deg. to the axis of the coil. When an alternating current passes through the coil the soft iron needle tends to set itself in the direction of the axis of the coil, and if it is suspended by a quartz fibre or metallic wire so as to afford a control, it can become a metrical instrument. Another arrangement, devised by J.A. Fleming in 1887, consists of a silver or copper disk suspended within a coil, the plane of the disk being held at 45 deg. to that of the coil. When an alternating current is passed through the coil, induced currents are set up in the disk and the mutual action causes the disk to endeavour to set itself so that these currents are a minimum. This metal disk galvanometer has been made sufficiently sensitive to detect the feeble oscillatory electric currents set up in the receiving wire of a wireless telegraph apparatus. The Duddell thermal ammeter is another very sensitive form of alternating current galvanometer. In it the current to be detected or measured is passed through a high resistance wire or strip of metal leaf mounted on glass, over which is suspended a closed loop of bismuth and antimony, forming a thermoelectric couple. This loop is suspended by a quartz fibre in a strong magnetic field, and one junction of the couple is held just over the resistance wire and as near it as possible without touching. When an alternating current passes through the resistance it creates heat which in turn acts on the thermo-junction and generates a continuous current in the loop, thus deflecting it in the magnetic field. The sensitiveness of such a thermal ammeter can be made sufficiently great to detect a current of a few microamperes.

References.--J.A. Fleming, _A Handbook for the Electrical Laboratory and Testing Room_, vol. i. (London, 1901); W.E. Ayrton, T. Mather and W.E. Sumpner, "On Galvanometers," _Proc. Phys. Soc. London_ (1890), 10, 393; H.R. Kempe, _A Handbook of Electrical Testing_ (London, 1906); A. Gray, _Absolute Measurements in Electricity and Magnetism_, vol. ii.