4

OXFORD UNIVERSITY.

colleges the restriction of celibacy has been, under certain conditions, remitted in the case of fellows engaged in college work. Under a statute passed in 1868, any person may now become a member of the university, without becoming a member of a college or hall, provided he satisfies certain disciplinary requirements. For such purposes these unattached students are under the control of a board of delegates; but no special provision is made for their instruction. In 1871, the new foundation of Keble College, built in memory of John Keble, was admitted to enjoy the same privileges (save as regards the academical status of its head) as are possessed by the existing colleges and halls.

College. Other notable buildings are the Town Hall, the Radcliffe Infirmary, the County Gaol, and one or two dissenting places of worship, including a Wesleyan and an Independent Chapel. Lady Margaret Hall and Somerville Hall, founded in 1879 for lady students taking advantage of the lectures of the Oxford association for promoting the higher education of women, are not as such connected with the university. O. is a mart for the disposal of the agricultural produce of the neighboring country, but has little trade of its own, and is dependent for its prosperity chiefly on the university. It is a municipal and parliamentary borough, and governed by a mayor, nine aldermen, and thirty councillors, whose jurisdiction, however, does not embrace the university. The university sends two members to parliament; the city sent two also, but was disfranchized for bribery from 1883 to 1890. O., by the Saxons called Oxnaford, and in Domesday Book, Ox-tration of the university, and possessed the exclusive power of eneford (probably a ford for oxen '), is a place of great antiquity. The date of its origin is unknown, but as early as the 8th c. there was a nunnery established here; and in 802, an act of confirmation by Pope Martin II. describes it as an ancient seat of learning. It is said to have been a residence of King Alfred, and also of Canute, who held several parliaments within its walls. The townsmen closed their gates against William the Conqueror, who stormed the town in 1067, and gave it to one of his followers, Robert d'Oyley, who built a castle here to overawe the disaffected Saxons, some ruins of which are still to be seen. The paction that terminated the strife between Stephen and Henry II. was drawn up at Oxford. In the reign of Edward III., the preaching of Wickliffe excited great commotion among the students, and threatened well-nigh the dissolution of the university. In the reign of the 'Bloody Mary,' it witnessed the mar-years. tyrdoms of Ridley, Latimer, and Cranmer; and during the great civil war of the 17th c., it was for a while the head-quarters of the Royalist forces, and was conspicuous for its adherence to Charles I. Ever since that period the city-or, at any rate, the university-has been in general characterized by an extreme devotion to the church' and the 'king.'

Previous to the statute 17 and 18 Vict. c. 81, the constitution of the university was as follows: 1. The Hebdomadal Board, or Weekly Meeting, consisting of the Heads of Houses and the two Proctors, which body exercised the chief share of the adminisinitating legislation; 2. Congregation, consisting of certain university dignitaries, which met merely for the purpose of conferring degrees; 3. Convocation, consisting of all Masters of Arts, a body whose consent was necessary before any of the measures proposed by the Hebdomadal Board could become law, which elected the chancellor, the two representatives of the university in parliament, several of the professors, and dispensed the ecclesiastical patronage of the university. The statute referred to introduced important changes. The Hebdomadal Board has been changed into the the Hebdomadal Council, consisting of the chancellor, the vice-chancellor, the proctors, six heads of houses, six professors, and six members of convocation of not less than five years' standing-such heads, professors, and members of convocation being elected by congregation, and holding office for six

Congregation, again, now consists of all the great officers of the university, the professors, public examiners, and all resident masters; and on this body is now bestowed the power of accepting or rejecting, and of amending any statue framed by the Hebdomadal Council. The composition and powers of Convocation remain unchanged. The students not on the foundation are for the most part commoners. In Worcester College and the halls there is still a class of fellow-commoners, who pay larger fees and enjoy certain privileges. They mainly consist of men above the ordinary age of undergraduates, who wish to have the intellectual advantages of the university without being subjected to the common routine of discipline. All other formal distinctions due to wealth or poverty are almost entirely abolished; such as the special privileges of peers, and the regard had to the poverty of candidates in the case of certain scholarships. It is very difficult to ascertain the actual number of students at any one time in Oxford, but now it is probably seldom above 1800.

OXFORD UNIVERSITY is said to have been founded by King Alfred. Without claiming for it an origin quite so ancient, it is rertain that from very early times students resorted to Oxford in order to attend lectures there delivered by learned men, and that they lived in the houses of the townspeople. In some cases they combined together, so as to secure the service of a common teacher, with whom they lived in a large tenement called an inn, hostel, or hall. For a long time, however, the great majority of the students lodged in rooms hired from the citizens; and as late as the year 1512, regulations were made for the governance of such students. As their numbers increased, the halls were multiplied. Anthony Wood states that he could show the names and places of more than a hundred. A great diminution in the numbers of the students took place about the middle of the 15th century, This, among other causes, led to the gradual disappearance of the halls, which were bought up by the wealthier colleges. Only five of the halls now exist, which differ from the colleges only in that they are unincorporated, and have little or no endowments. Residence in private lodgings had also fallen into disuse; and by the time of Queen Elizabeth, it had become a compulsory rule that all undergraduates should reside in some college or hall, at least for the first twelve terms of residence. Now, however, undergraduates may in most colleges live in lodgings from the be-four weeks may be taken as the ordinary length of the academic ginning of their course.

There are four terms in each year-viz., Michaelmas Term, which begins on the 10th of October and ends on the 17th December; Hilary Term, which begins on the 14th of January and ends the day before Palm Sunday; Easter Term, which begins on the Wednesday in Easter-week, and ends on the Friday before Whitsunday; Trinity Term, which begins on the Saturday before Whitsunday and ends on the Saturday after the first Tuesday in July. Full Term, as it is called, does not begin till the first day of the week after the first congregation is held. By undergraduates, Michaelmas and Hilary Terms are kept by six weeks' residence, and Easter and Trinity Terms by three weeks each; but more than this is required by most of the colleges. Twentyyear. Twelve terms of residence are required for the degree of B. A. from all.

The colleges were founded at various periods, from the end of the 13th c. to the beginning of the 18th. Fourteen out of the 20| The degree of M.A. is obtainable in the twenty-seventh term were founded before the Reformation. Their object originally after matriculation. By a statute passed in 1850, the following was to support limited societies of students, who were to devote examinations were made necessary for a degree in arts; but their their lives to study-by no means, as at present, to educate large nature has been considerably changed by the new statutes which classes of the community. Students, other than those on the came into effect 1873-1874: 1. Responsions, called Little Go' or foundation, seem not to have been regarded by the founders as Smalls' in the familiar language of undergraduates, are obligaan essential part of the college. The colleges arose, as has been tory upon all. The university does not, as to this or any other already said, partly instead of the old halls, and were partly at pass examination, fix a limit of time within which they must be first connected with the monasteries, it being by means of these passed; but most colleges require their members to pass responinstitutions that benevolent persons were enabled to give perma- sions, at least within their first year of study. Subjects: one nent support to poor secular scholars. University and Balliol, Latin and one Greek author-or portions of them, as five books which now rank as the oldest colleges, were in point of fact halls of Homer, five of Virgil, two Greek plays, &c.-with a paper of supported by endowments held in trust for the maintenance of grammatical questions; a piece of English to be translated into their students. The originator of the collegiate system, in any-Latin; two books of Euclid, or algebra up to simple equations inthing like its present form, was Walter de Merton, who besides having founded Merton College, is entitled to the honor of having mainly contributed to fix the university in its present site. All those on the foundation of the colleges before the Reformation were called Clerici. The great majority of the fellows were required to take priest's orders within a certain period after their election. This requirement of course involved celibacy, which, besides, was expressly imposed in some colleges; and practically, in old times as now, was enforced by the rule of life and the obligation of residence. Within the last few years, in some of the

clusive; and arithmetic. 2. The First Public Examination, or Moderations, is also obligatory upon all. Candidates must have entered upon their fourth term. Subjects: the Four Gospels in Greek (except in the case of persons not members of the Church of England, when some one Greek author is to be substituted); one Greek and one Latin author, not the same as those offered for responsions, and one most be a poet, the other an orator; a piece of English into Latin, and a paper of grammatical questions; logic, or Euclid III. and IV., 1-9, and algebra. Honors are awarded at this examination both in classics and pure mathemat

ics. Candidates are recommended to take up especially poets and position in Latin verse, Latin prose, and English prose; the Gaisorators. Verses, as well as Greek and Latin prose-writing, and a ford prizes for Greek composition; and the Arnold, Stanhope, and paper of grammatical and philological questions, are set. In the Marquis of Lothian's prizes for the best essays on an historical mathematical school, which in this examination exists as a separate subject. But the great prizes are the scholarships and the fellowschool for honors only, candidates are examined in pure mathe- ships. By the commissioners under 17 and 18 Vict. c. 81, these matics up to the Integral Calculus and the Calculus of Finite Dif- | have been for the most part thrown open, and are now awarded ferences inclusive. after examination without restrictions as to kin or place of birth. 3. The Second Public Examination, held twice a year, to be At All-Souls, and also at St. John's College, since the labors of passed not earlier than the 12th term, and for honors not later than the commissioners, an attempt has been made to keep up the forthe 16th term of standing; unless the candidate has been classed mer exclusiveness. The scholarships, which are so numerous as in some other school of the Second Public Examination, in which to be within the reach of any young man of ability, range from case he may be admitted up to the 20th term inclusive. This £60 to £80 a year, with rooms free, which would go a considerexamination consists of three parts: (1.) an examination in the able way towards defraying the expense of a university educarudiments of faith and religion, or in the case of those who (or tion. At the close of this education come the fellowships; and it whose guardians) object to such examination, certain substituted has been calculated that when the arrangements of the commisbooks or subjects; (2.) an examination of those who do not seek sioners are complete, there will be between 20 and 30 fellowships, honors; and (3.) an examination of those who do seek honors. In mostly about £300 per annum, open yearly to competition. this last there are, in Oxford phraseology, six schools: Literæ Oxford is, of course, chiefly fed from the great English schools. Humaniores, Mathematics, Natural Science, Jurisprudence, Mod- A close connection subsists, by the terms of the foundation, beern History, Theology. Candidates are entitled to a degree of tween Winchester and New College, between Westminster and B.A. who, having passed the two previous examinations, also Christ Church, and between Merchant Taylors' and St. John's. passed the examination appointed for those who do not seek For the nature of this connection, see under these colleges. A honors, or who obtain honors in any one of the six honor- student desirous of going to Oxford, must apply to the Head of schools. But every candidate, except he has obtained honors in the College to which he wishes to belong. Application in former the Theology School, must have satisfied in the rudiments of times had to be made early, as all the good colleges were filled up faith and religion or the substitute. By these rudiments are un- for several years in advance. But now that undergraduates are derstood the Old and New Testaments (Gospels and Acts of the allowed by most colleges to live in lodgings from the first, a canApostles in the original Greek); and the 39 articles. The pass didate can have no difficulty in securing admission even to a disexamination embraces subjects chosen from at least two out of tinguished college at short notice. There is no university examthe three following groups: (a) Greek and Roman history and ination at matriculation; but all the good colleges have such an philosophy; (b) English modern languages, political economy, and examination before they receive any one-the standard of the law; (c) geometry, mechanics, chemistry, and physics. Out of examination, of course, varying with the college. After being these the candidate must select three subjects, one of which must received into the college, the undergraduate is sometimes assigned be either (1) ancient philosophy and history (in the original to a college tutor, who exercises a special control over his readGreek, or Greek and Latin); or (2) a modern language, (French ing; but he also attends the instruction of the other college tutors or German). The classical books must be other than those offered or lecturers, as the course of his studies may require. The cost for Responsions and Moderations. Candidates for honors may of tuition varies at different colleges, but an average of £65 may select any one, or more than one of the six schools. The most be given as paid by the undergraduate during his whole career. popular and influential of these is the school of Literæ Humani- This payment is at some colleges distributed over three, at others ores. The examination in this school includes (1) the Greek over four years. Besides this, almost every undergraduate finds and Latin languages; (2) the histories of ancient Greece and Rome; it necessary, at some period before taking his degree, to read with (3) logic, and the outlines of moral and political philosophy. a private tutor, whom he chooses for himself. Private tuition has Candidates may also offer certain special subjects in any of these grown to be quite an institution in Oxford, though not formally three departments. The republic of Plato and the ethics of Aris-recognized. Many of the ablest young men, after taking their totle form the basis for philosophical study, though they are degree, remain in Oxford for a year or two, taking private pupils. every year more largely supplemented by modern philosophy. In this way an undergraduate, even of a badly taught college, Next in the numbers of its candidates is the School of Modern could secure the advantages of the best tuition. But during the History, which includes (1) the continuous history of England; last few years, the lecturers in different colleges have more and (2) general history during some period, selected by the candidate, more combined and systematized their work; and thus to a slight from periods to be named from time to time by the Board of extent obviated the need for private tuition. Studies; (3) a special portion of history, or a special historical subject, carefully studied with reference to original authorities. The School of Jurisprudence includes (1) general jurisprudence; (2) the history of English law; (3) some department of Roman, and it may be, of English law; (4) international law, or a spcified department of it. The School of Mathematics embraces pure and mixed mathematics (algebra, trigonometry, calculus, mechanics, optics, astronomy). The School of Natural Science has a double examination for honors-a preliminary and a final. The preliminary examination, incumbent upon all, is restricted to the elemen-endowments of old ones were increased by the commissioners, tary parts of mechanics, physics, and chemistry. In the final examination, the candidate may offer himself for examination in one or more of the three general subjects of physics, chemistry, and biology. The examination in the Honor School of Theology includes the Holy Scriptures, dogmatic and symbolic theology, ecclesiastical history and the fathers, the evidences of religion, liturgies, sacred criticism, and the archæology of the Old and New Testaments. A knowledge of Hebrew will have weight in the distribution of honors. The organization of these schools is at present the main function of the university, as distinct from the colleges. Professorial teaching on its own account only exists to a very limited extent. In the main, the teaching power of the colleges is devoted to preparing their undergraduate members for these various examinations.

Examinations also takes place for degrees in law, medicine, divinity, and music; but these are in great measure formal. The examinations for degrees in arts, are the proper work of the university.

Besides these honors, various distinctions are conferred by the university. There are several university scholarships, more particularly the Vinerian law fellowships and scholarships; the Eldon law scholarship; one Sanscrit and two Hebrew scholarships yearly; two mathematical scholarships; the Hertford scholarship, for the encouragement of the study of Latin, and the Ireland and Craven scholarships, for the encouragement of the study of classics. There is also the Newdigate prize for the best composition in English verse; and the three chancellor's prizes for the best com

Much discussion has taken place on the merits and faults of this system; but, on the whole, it must be allowed to be useful for the tutor, as clearing up and concentrating his knowledge, while, at least to undergraduates who read for honors (with a few rare exceptions), it may be considered as absolutely necessary. Private tutors usually charge £10 a term for three hours a week. Previous to 1852, the professoriate of Oxford was strictly ornamental. A great effort was then made to stir it into life, which has been partially successful. New professorships were created, and the under 17 and 18 Vict. c. 81. But the former of these measures, at least, whatever it may have done for the interests of science, has produced but little effect on the undergraduates. They still limit their range of studies by the requirements of the examinations of the schools, and it were hard to expect them to do otherwise. But professorial teaching has undoubtedly become more popular in the ordinary branches of study. Lectures by the professors of Law and Modern History, of Moral Philosophy, Logic, Greek, and Latin, are felt to be useful, and are therefore well attended. Considerable changes in the university system were contemplated in 1881, in accordance with the reforms suggested by the university commissioners. Amongst other changes, it was proposed that professors should do more of the teaching, and that fellowships should be more numerous, of less value, and of shorter tenure than at present.

The expenses vary at different colleges, not only indirectly from the tone of the society, but even directly from the charges made for necessaries. A man should be exceedingly comfortable at Oxford with £200 a year; on £150, he can manage with economy. There have been instances of men passing creditably through the university course on £100 a year; the necessary expenses do not exceed that sum. It appears that some unattached students cover their board, lodging, and tuition for about £45 a year. Discipline inside the college is maintained by the head of the house and the tutors; in the town and its neighborhood, by the proctors, who are university officers invested with great authority. As a rule, this authority is well exercised. According

6

OXFORD CLAY-OXYGEN.

to the Universities Commission Report (1874), the revenue of the colleges and university in 1871 was £413,000.

The following is a list of the colleges and halls as they rank in the university; an account of each will be found in its alphabetical place: University, Balliol, Merton, Exeter, Oriel, Queen's, New College, Lincoln, All Souls, Magdalen, Brasenose, Corpus Christi, Christ Church, Trinity, St. Jolin's, Jesus, Wadham, Pembroke, Worcester, Keble, St. Mary Hall, Magdalen Hall, New Inn Hall, St. Alban Hall, St. Edmund Hall. To these may be added Charsley's Hall, being a private hall under the mastership of W. H. Charsley, in virtue of a statute passed in 1854, empowering any M.A. of a certain standing to open a private hall on his obtaining a license from the vice-chancellor. The Unattached Students now number upwards of 100; but the present system of university teaching is not very favorable either to their increase or progress.

Among the books which may be consulted are-Ayliffe's History of Oxford, Wood's Annals, the University Calendar, the Report of the Royal Commissioners for 1852, and the Student's Handbook to the University of Oxford.

OXFORD BLUES. See HORSE GUARDS, ROYAL. OXFORD CLAY, the principal member of the Middle Oolite series, is a bed of stiff dark-blue or blackish clay, sometimes reaching a thickness of 600 feet. There occur in its lower portion in some places layers of tough calcareous sandstone, called Kelloway Rock, from a place in Wiltshire, where it is quarried. The O. Č. lies beneath the plain on which Oxford is built, and extends south-west and north-east from the shore Weymouth to the fen lands south of the Wash, thence it may be traced through Lincoln into Yorkshire, until it disappears under the sea at Scarborough. The close packing of the fossils in the fine compact clay has caused them to be beautifully preserved; the shells frequently retain their iridescence, and even the softer parts of the cephalopods have sometimes left with tolerably clear definition their form in the clay. The fossils are, however, often filled with iron pyrites, which, on exposure to the atmosphere, readily decomposes and destroys all traces of the beautiful organism. The remains of chambered shells of the genera belemnites and ammonites are very abundant, and with them are associated other shells, interesting crustacea, and the species of fishes and reptiles

which are characteristic of the oolite.

general, all oxides require as many equivalents of acid as they contain atoms of oxygen in their composition. Some of the metallic acids, like the stannic and titanic, contain two atoms of oxygen to one atom of metal, but most of them contain three atoms of oxygen-such, for example, as the manganic, ferric, chronic, tungstic, molybdic, and vanadic acids; whilst in a few cases, such as the arsenic, antimonic, and permanganic, the proportion of oxygen is still higher.'-Miller's Inorganic Chemistry, 2d edit. p. 314.

Of the basic oxides, which form by far the most important class, it may be observed that they are devoid of all metallic appearance, and present the characters of earthy matters, and that six only of them are soluble in water to any considerable extent -viz., the three alkalies, and baryta, strontia, and lime. All the oxides are solid at ordinary temperatures, and as a general rule, the addition of oxygen to a metal renders it much less fusible and soluble; the protoxide of iron, the sesquioxide of chromium, and molybdic acid being the only oxides that melt more readily than the metal.

OXLEY A, a genus of trees of the natural order Cedrelacea, of which one species, O. xanthoxyla, the YELLOW WOOD of Eastern Australia, is a very large tree, 100 feet high, valuable for its

timber.

O'XUS, the ancient name of a great river in Central Asia, which is called by the Turks and Persians JIHUN, and AMU or AMU-DARIA by the natives of the country through which it flows. The O. rises in Lake Sari-kol, in the elevated plateau which separates Eastern and Western Turkestan. It flows through Buddakshan, Bokhara, and Khiva, and empties itself by In the first part of its several mouths into the Sea of Aral. course, its volume is increased by numerous affluents, but it receives no tributaries after entering Khiva, from which point its course is wholly through a dry sandy desert. Its total length is about 1150 miles. The value of the Oxus for the purpose of water communication, is said by recent Russian geographers to have been much overrated in Europe; and they add that in summer, vessels of even slight draught could only be got upon the stream by shutting off the irrigation canals, and risking the desolation of the country dependent on them for its crops. The true value of the Oxus lies in the means it will supply of irrigating the sterile alluvial wastes through which it runs.

Before the Christian era, it is believed that the Oxus flowed into the Caspian, and that since 600 A.D. it has twice changed its course (see ARAL). A great part of the old bed of the Oxus has recently been explored by M. Stebnutzki (Bulletin de la Soc. de Géogr. de Paris, April 1871), who has ascertained that it has a fall towards the Caspian, from which he infers that its course was not changed by an upheaval of the Turcoman desert, but by the simple accidents of fluvial action on an alluvial soil. In his address to the London Geographical Society in May 1872, Sir Henry Rawlinson said the restoration of the Oxus to its old bed ment, that it was a work of no engineering difficulty whatever, and would assuredly be accomplished as soon as the neutrality of Khiva was secured.-See A Journey to the Source of the Oxus, by John Wood, with Essay of the Geography of the Oxus Valley by Colonel Yale, 1873; also The Road to Mero, by Sir H. Rawlinson, in the Proceedings of the Geog. Society, 1879.

OXFORDSHIRE, an inland county of England, bounded on the S. by the River Thames, E. by Bucks, W. by Gloucester. Area, 472,717 acres. Pop. (1871) 177,975; (1881) 179,650. The surface, where it is not level, is undulating. In the north-west the hills rise in Broom Hill to 836 feet above sea-level, and in the south-east of the county are the Chiltern Hills (q. v.), rising near Nutfield to 820 feet in height. It is watered along its southern border by the Thames, and the other chief rivers are the Windrush, Evenlode, Cherwell, and Thame, affluents of the Thames. By means of the Oxford Canal, which joins the Thames at Ox-was then under the serious consideration of the Russian governford, the towns and districts lower down the river (Abingdon, Wallingford. &c.), are supplied with coal from the Leicestershire coal-fields. The soil is fertile; the state of agriculture is advanced, 417,606 acres being under crops, fallow, or grass, in 1881; and the county may be considered one of the most productive in the country. Three members are returned to the House of Commons for the county.

OXIDATION is the term applied to the union of any body with oxygen, the body being then said to be oxidized, and the resulting compound being termed an oxide. Many bodies possess the property of entering into several distinct combinations with oxygen. For example, manganese (Mn) forms no less than six such compounds - viz., MnO, Mn,O,, Mn,O.. MnO2, MnOs, Mn,O,, which represent different stages of oxidation.

OXYA'CIDS. When Lavoisier, in 1789, gave the name of oxygen to the Dephlogisticated Air discovered, in 1774, by Priestley, he believed that the presence of that body was essential to the existence of an acid, and this view was supported by the composition of the principal acids which were then known, such as acids were discovered into which no oxygen entered, but which sulphuric, nitric, carbonic, and phosphoric acids. But, by degrees, always contained hydrogen, and hence acids were divided into O'XIDES, METALLIC, are the most important of all the com- two great classes, the oxyacids and the hydracids; oxygen being pounds of the metals, and in many cases occur naturally as abun- supposed to be the acidifying principle in the former, and hydrodant and valuable ores. They are divided by chemists into three gen in the latter. At the present day, scientific chemists usually classes-viz., (1) basic oxides or bases, (2) saline or indifferent ox- restrict the term acid to compounds into which hydrogen enters, ides, and (3) acid oxides or metallic acids. The different oxides and the acids are regarded as salts of the last named element; of the same metal usually afford illustrations of two, and not un- thus sulphuric acid (HO,SO,) and nitric acid (HO, NO,) are the sulfrequently of all three of these classes. Thus (to take the case of plate and nitrate of oxide of hydrogen; hydrochloric acid (HCl) manganese referred to in the last article) the protoxide (MnO) is a | is chloride of hydrogen, &c. powerful base, the red oxide (Mn,O,) is a saline or indifferent oxOXYCHLOʻRIDES, chemical compounds containing both ide, showing little tendency to combine either with acids or alka-chlorine and oxygen in combination with some other element or lies, while permanganic acid (Mn,O,) presents all the properties radical. Chloride of lime (CaOCl), chloride of potash (KOCl),

of an acid. 'As a general rule, the greater the number of atoms of oxygen which an oxide contains, the less is it disposed to unite with the acids; on the contrary, it frequently possesses acid properties, and then unites with bases to form salts. Protoxides generally are strong salifiable bases; they require one equivalent of a monobasic acid to form neutral salts. Sesquioxides are weaker bases; their salts are usually unstable; they require three atoms or equivalents of a monobasic acid to form a salt which is neutral in composition, though it may not be neutral to test-paper; and in

oxychloride of lead or Turner's yellow belong to this class.

O'XYGEN (symb. O, equiv. 8; new system, 16-see CHEMISTRY.-sp. gr. 1-1056) is a colorless, inodorous, tasteless gas, long regarded as a permanent' gas, but liquefied by Pictet of Geneva for the first time in 1877. Its chemical affinities for other elementary substances are very powerful; with most of them it is found in combination, or may be made to combine, in more than one proportion; with several in 4, 5, or 6 proportions; and there

OXYRHYNCHUS OYSTER.

7

is only one element (fluorine) with which it does not enter into dence by a few weeks. Priestley gave it the name of Dephlogis any combinatiou. Owing to the intensity with which many of ticated Air; Scheele termed it Empyreal Air; Condorcet shortly these combinatious take place, this gas has the power of support-afterwards suggested Vital Air, as its most appropriate designa ing Combustion (q. v.) in an eminent degree. Of all known sub- tion; and in 1789, Lavoisier, who, by a series of carefully constances, it exerts the smallest refracting power on the rays of ducted and very ingenious experiments, proved that the combuslight. It possesses weak but decided magnetic properties, like tion of bodies in the air consisted essentially in their chemical those of iron, and like this substance, its susceptibility to mag- combination with oxygen, and thus overthrew the Phlogistan (q. v.) netization is diminished or even suspended by a certain elevation theory, gave it the name which it now retains in consequence of of temperature. It is only slightly soluble in water; 100 cubic his (erroneously) believing that it possessed a certain property inches of that liquid dissolving 4:11 cubic inches of gas at 32°, which is described in the article OXYACIDS. and only 2.99 inches at 59°.

Oxygen gas is not only respirable, but is essential to the support of animal life; and hence it was termed vital air by some of the older chemists. A small animal placed in a bell-glass containing pure oxygen will not be suffocated so soon as if it were placed in the same glass filled with atmospheric air. For further details on this property of oxygen, the reader is referred to the article RESPIRATION. Oxygen is the most abundant and the most widely distributed of all the elements. In its free state (mixed but not combined with nitrogen), it constitutes about a fifth of the bulk, and considerably more than a fifth of the weight of the atmosphere. In combination with hydrogen, it forms eight-ninths of all the water on the globe; and in combination with silicon, calcium, aluminium, &c., it enters largely into all the solid constituents of the earth's crust; silica in its various forms of sand, common quartz, flint, &c.-chalk, limestone, and marble-and all the varieties of clay, containing about half their weight of oxygen. It is, moreover, found in the tissues and fluids of all forms of animal and vegetable life, none of which can support existence independently of this element.

There are various modes of obtaining oxygen, the simplest of which consists in the exposure of certain metallic oxides to a high temperature. It was originally obtained by its discoverer, Dr. Priestly, from the red oxide of mercury, which, when heated to about 750°, resolves itself into metallic mercury and oxygen gas. It may be similarly obtained from red oxide and peroxide of lead, the resulting products in these cases being protoxide of lead and oxygen. The following are the chief methods now employed: (1.) The black oxide (or binoxide) of manganese (MnO,) is much employed as a source of this gas. The mineral is reduced to small pieces of about the size of a pea, and introduced into an iron bottle, with a pipe through which the gas may escape. When the bottle is placed in a furnace, and attains a red heat, the mineral parts with one-third of its oxygen and the red oxide of manganese (MuO,Mn,O,) remains behind; the reaction being explained by the equation:

(2.) A very pure and abundant supply of oxygen may be obtained by heating chlorate of potash (KO,CIO), which yields up all its oxygen (amounting to 39.16 per cent.), and leaves a residue of chloride of potassium. One ounce of this salt yields nearly two gallons of oxygen gas.

It is found by experiment, that if the chloride of potash is mixed with about a fourth of its weight of black oxide of copper, or binoxide of manganese, the evolution of the gas is greatly facilitated, although the oxides do not seem to undergo any change during the process. (3.) Oxygen is readily obtained by heating strong sulphuric acid with about half its weight of pow dered black oxide of manganese, or chlorate of potashi, in a glass retort; the reaction in the former case being expressed by the equation:

Black oxide
of Manganese.
MnO,

Sulphate
of Manganese.
MnO,SO,

+

Sulphuric acid.
HO,SO,

Water. но +

=

Oxygen. + 0

OXYHYDROGEN MICROSCOPE. See SOLAR MICROSCOPE. OXYRHY'NCHUS, the name of a celebrated Egyptian fish, said to be reverenced throughout Egypt, and sacred to the goddess Athor. Its name in Egyptian is kha, and the fish in the hieroglyphs was used for this syllable, and particularly expressed the idea of the body. In the ritual, the deceased particularly stated that he had not caught this fish. The name appears to have comprised the genus Mormorus, distinguished by its pointed nose and long dorsal fin. The fish was worshiped in one of the nomes, which was called after it, and the inhabitants held it in such reverence that they would not touch any fish captured by a hook. When the portions of the body of Osiris were flung into the Nile, this fish alone ate one portion of his body. The Ŏ. was not eaten in Egypt, except by the natives of the Cynonopolites Nomos. Its modern names is Mizeleh, which seems retained in the Coptic Pemge, the name of the city of Oxyrhynchus. It is represented both in the sculptures and on the coins of the Nome, and was anciently embalmed. The city of Oxyrhynchus is the modern Behneseh, lying on the west bank of the Nile, in Lower Egypt, near the Bahr-el-Jusuf.

OXYU'RIS VERMI'CULARIS is the name now assigned by most zoologists to the intestinal worm described as Ascaris (q. v.) vermicularis, yet it is the original and true Ascaris. For the mode suffering from its presence, the reader is referred to the articles of recognizing the presence of this worm, and treating patients VERMIFUGES and WORMS.

O'YER AND TE'RMINER Fr. ouir, to hear; terminer, to determine). A commission of oyer and terminer is granted by the crown to the judges and others to hear and determine all treasons, felonies, and trespasses; and it is by virtue of this commission that the judges on circuit dispose of criminal cases in the various circuits. Sometimes a special commission of the same kind is issued, authorizing the judges to go and try prisoners at other than the ordinary times.

O'YSTER (Ostrea), a genus of lamellibranchiate molluscs, of the section with a single adductor muscle. See LAMELLIBRÁNCHIATA. The shell consists of two unequal and somewhat irregularly shaped valves, of laminated and coarsely foliated structure; and the hinge is without tooth or ridge, the valves being held together by a ligament lodged in a little cavity in each. The animal is, in its organization, among the lowest and simplest of lamellibranchiate molluscs. It has no foot; and, except when very young, no power of locomotion, or organ of any kind adapted to that purpose. Its food consists of animalcules, and also of current of which is directed towards the mouth by the action of minute vegetable particles, brought to it by the water, a continual the gills. The gills are seen in four rows when the valves of the shell are separated, a little within the fringed edge of the mantle. In the most central part is the adductor muscle; towards the hinge is the liver, which is large; and between the adductor muscle and the liver is the heart, which may be recognized by the brown color of its auricle.

The mouth-for, as in the other lamellibranchiata, there is no head-is situated beneath a kind of hood, formed by the union of the two edges of the mantle near the hinge. It is jawless and toothless. The ovaries are very large during the season of reproduction, which extends over certain months in summer, when oysters are out of season for the table. Oysters are hermaphrodite. They produce vast numbers of young. Leeuwenhoek calculated that from 3000 to 4000 exist within an O. at once when 'sick,' milky' or full of spawn; and according to Poli, one O. produces about 1,200,000 eggs. The eggs are hatched within the shell and mantle of the parent, and the young are to be seen swimming slowly in a whitish and mucous or creamy fluid surrounding the gills, which becomes darker and of a muddy appearance when they are about to be expelled. Each young O. is then about th of an inch in length, and about two millions are capable of being closely packed in the space of a cubic inch. When the parent O. expels the young, and this is done simultaneously by multitudes on an oyster-bank, the water becomes filled as with a thick cloud, and the spawn-called spat by fishermen-is wafted Of the compounds of oxygen, it is unnecessary to speak here, away by currents; the greater part, of course, to be generally as they are described in the article on the other chemical elements. lost, by being driven to unsuitable situations, as exposed rocks, Oxygen was discovered almost simultaneously, in the year 1774, muddy ground, or sand to which it cannot adhere, or to be deby Priestley and by Scheele, the English chemist having the prece-voured by fishes and other marine animals, but some to find an

and in the latter case, being of a more complicated character. (4.) Various processes have been proposed for obtaining the gas on a large scale, of which the following, recommended by St. Claire Deville and Debray, is perhaps the best: The vapor of hydrated sulphuric acid is passed over red-hot platinum, by which it is decomposed into oxygen and sulphurous acid, the latter of which may easily be separated (and made available for the formation of sulphites) by its solubility in water or alkaline solutions. It has been calculated that a cubic mètre (35.375 cubic feet) of oxygen costs 88. 4d. when obtained from chlorate of potash; nearly 48. 1d. when obtained from manganese; and only 10d. when obtained from sulphuric acid.

object to which it can attach itself for life. The young come the beds or banks which yield it for the markets of Britain and forth furnished with a temporary organ for swimming, ciliated, and provided with powerful muscles for extending it beyond the valves and withdrawing it at pleasure; and when the O. has become fixed in its permanent place of abode, this organ, being no longer of any use, has been supposed to drop off, or gradually to dwindle away and disappear.

The usual mode of taking oysters by dredging is destructive, although, for oyster-beds, which are at all states of the tide covered with a considerable depth of water, nothing better has been devised, and the anxiety of fishermen to make the most of the present opportunity has caused many beds to be almost ruined by over-dredging. But the artificial formation of oyster-beds has been resorted to with great promise of success. It is indeed no novelty, having been practiced by the Romans. Pliny says that 'the first person who formed artificial oyster-beds was Sergius Orata, who established them at Baiæ. . . This was done by him, not for the gratification of gluttony, but for the sake of gain, as he contrived to make a large income by the exercise of his ingenuity.' Sergius Orata lived in the time of Augustus. Among the vivaria of later emperors and other wealthy Romans were ostrearia, specially devoted to oysters; and oyster-culture has never ceased to be practised in Italy, although to an inconsiderable extent, and particularly in Lake Fusaro, the Acheron of Virgil, a muddy saltwater pond, nowhere more than two yards deep. In Britain, it has also long been practised to some extent, particularly on the coasts of Kent and Essex, for the supply of the London market.

In 1864, an act of parliament was passed, giving exclusive rights to a Company, called the Herne Bay, Hampton, and Reculver Oyster Fishing Company,' over a certain portion of the Com-shore at Herne Bay, extending about six miles in length by 14 in breath. The oyster-beds fished by the public had, till then, yielded a very small supply; and it was urged that this supply could be largely increased by a well-managed Company. In order that the public should not be injured by this legislation, it was declared by one of the clauses of the Act that If the Company fail to maintain and cultivate the beds, or to produce well-fed oysters fit for the public market in such quantities as to be of public advantage, all the privileges conferred on the Company would be withdrawn, and the dredging of the beds, as formerly, thrown open to the public to fish.'