IBS 



OVALBUMEN. 



OXALIC ACID. 



iu'uhich the oval ha* become a point (the origin), and is a eaojugalt 

 win! [CUBVK], an isolated point which is not on any continuous 

 branch. 



Some conjugate pointa have none but imaginary values of <li/:<ljr. 

 ome have one or more finite values. Thus when y = f^(3?b', there 

 is a conjugate point at the origin, and dy.dje is then imaginary : but 

 when yrs.r'V*** **) there ia also a conjugate point at the origin, but 

 (//:. /j- is 0. The meaning seems to be (as far as we can judge from a 

 few instances) that when the oval during its diminution, has axes 

 which preserve a finite ratio to one another, so that its tangents fall in 

 all directions, the ultimate value of dy.ds is imaginary. But when 

 one of the axes diminishes without limit OB compared with the other, 

 so that, except near the ends of that axis, the tangents tend to assume 

 ..IK- direction, there is an ultimate value of dy.ilj- which defines that 

 :.>n. If our surmise be correct, a double or triple value of <///:<< 

 at the conjugate point would indicate the evanescence of a star-shaped 

 oval, or of one which tends to assume that form as it diminishes. But 

 this, with other points relating to the singular values of algebraic 

 functions, has yet to be fully considered. 



OVALBUMEN. A name given to the albumen of the hen's egg to 

 distinguish it from the albumen of blood (seralbumcn) which differs 

 somewhat from the former. 



OVARIAN DROPSY. RVOMB, DISEASES OF.] 



OVATION. [TBIUMI-H.J 



OVERSEER, an officer appointed by justices of counties or 

 boroughs, for parishes under the 43 Eliz., 2, and for townships under 

 the 13 & 14 Car. II., 12. They cannot be less than two nor more than 

 four for one parish or township. Churchwardens are ex-officio over- 

 seers of the poor. The duties of a paid assistant-overseer are identical 

 with those of an overseer, so far as they may be specified in the 

 warrant of justices, appointing the former under the 59 Qeo. Ill , 12, 

 s. 7, on account of the amount of the population, the extent of the 

 parish, or other difficulties, rendering the office of overseer onerous and 

 troublesome. Before the passing of the Poor-Law Amendment Act, 

 (4 & 5 Will. IV.. c. 7t>) it was the business of an overseer as well to 

 expend as to make out and collect the poor-rates. Where no select 

 vestry existed, he was judge of the necessities of applicants for paro- 

 clii.il "relief, an appeal in case of refusal lying before magistrates in 

 petty sessions. For an account of the abuses which arose from the 

 trust the law formerly confided to overseers, see the article POOR-LAW, 

 and the report of the commissioners for inquiring into the adminis- 

 tration of the poor law, published in 1834. 



The 4 & 5 Will. IV., c. 76, commonly known as the Poor- Law 

 Amendment Act. limited the authority of an overseer of the poor, by 

 ; i ring to a board of guardians such portion of his duties as 

 related to ascertaining fit objects for parochial relief, the amount of 

 relief to be given, and the manner of giving it. With such services 

 be has now little to do. His first business on entering upon his office 

 is to obtain from his predecessors the parish books and documents and 

 to collect outstanding arrears of poor rates, if any. If he have reason 

 to believe that any demand for money will be made upon him by the 

 guardians, he should forthwith make a poor rate, which must be 

 signed by a majority of the parish officers, allowed by the justices and 

 published A poor rate is due from every person assessed, immedi- 

 ately after it is published, and if any person refuse to pay the rate, 

 after a proper demand mode upon him, the same may be enforced by 

 distress and sale of the goods of the defaulter. If there should be no 

 goods to distrain upon, the defaulter may be committed to prison for 

 three mouths, unless the rate be sooner paid. The rate may be appealed 

 against at the next special sessions, after it is made, on the ground of 

 inequality or incorrectness ; and if the overseers have a good defence, 

 it will be their duty to defend the rate at the sessions. If they have 

 no valid defence, they should at once consent to the rate being quashed 

 or amended by the justices, as the case may require. If it should be 

 quashed they should then proceed to make a fresh rate, avoiding 

 the errors which led to the quashing of the former rate. 



An overseer is only to give relief to the poor " in any case of sudden 

 or urgent necessity ;" and, as soon as he is able, is to report to the 

 relieving-officer his having given such relief. The relief may not be 

 given in money, but only in articles of absolute necessity. At the end 

 of each half-year.the overseer will receive a notice from the district 

 auditor, to attend him in order that his accounts may be examined 

 and audited. He should take with him to the audit all his parish 

 books, letters, and papers, to any of which reference may possibly be 

 made. He is to manage and collect the rents of parish property, and 

 he has various duties cast upon him by statute and by the general 

 consolidated order of the Poor-Law Board, in connection with the 

 annual election of a guardian, or guardians, for his parish. Those 

 duties will be found fully set out in Mr. (Men's collection of Poor-Law 

 statutes and Poor- Law Board orders; and arc much too voluminous to 

 come within the limits of the present article. 



With regard to registration, his business is as follows : On the 

 20th of June in each year, he will affix on the church door a notice, 

 directing fresh claimanta for votes to make formal claim in writing to 

 the overseer on or before the 20th of July. His next step is to make 

 out for each parish an alphabetical lint of the names of all persons 

 already in the register, together with those of all claimants. This list 

 must be completed by the last day of July, and affixed on the church 



or chapel, and, if there be no church or chapel, in some conspicuous 

 .-it u.ition, on the two first Sundays in August. He must give copies of 

 this list for a reasonable payment, if required. On or before the _'.'>: h 

 of August, objections to votes may be received. An alphabetical li-t of 

 objections is to be posted, as before, on the two Sundays next preced- 

 ing the 15th of September. When the revising barrister hold* his 

 court, it will be the duty of the overseer to attend. His expenses 

 arising from his duties connected with registration are defrayed from 

 the poor-rate. So far with regard to registration of county voters. 

 Overseers of a parish situated in a borough, by the last day of .Inly, 

 without any claims being made, must make an alphabetical list of (Ar- 

 sons having a 101. qualification in respect to premises situated in 

 parish. A similar list of freemen must be made where freemen are 

 entitled to votes. These lists must be fixed as above. Claims from 

 persons omitted and objections are received on or before the 'jr.tli of 

 August, and lists of these claims, &c., are to be posted on the two 

 Sundays next preceding the 15th of September. The forms according 

 to which overseers are to frame their notices are to be found in the 

 acts of parliament whence their obligations arise. The limits of this 

 article do not admit of the duties of an overseer of the poor being fur- 

 ther enlarged upon ; the reader is therefore recommended to consult 

 the publications of the learned gentleman before referred to, which are 

 the standard works on the subject. 



OVERTURE (Ourcrtun, Fr., Sinfonia, ItaL), a musical composition 

 for a full instrumental band, introductory to an oratorio, open, or 

 ballet. An overture is a kind of musical prologue, and, as luoa, ought 

 to be in good keeping with the piece which it ushers in ; though in 

 most instances but little attention has been paid to the chanu 

 this important feature of the melodrama. There are some exceptions, 

 however, as in the fine overtures to ' Don Giovanni,' ' Der Frcischiitz,' 

 and ' A Midsummer-Night's Dream,' all of which fully prepare the 

 mind in so far as inarticulate sounds can prepare it for the romantic 

 stories and supernatural agency of the following scenes. 



The overture originated with Lully [LULLY, in Bioo. Div.], whose 

 compositions supplied many of the early Italian operas with an opening 

 instrumental piece. And indeed Handel himself imitated to a O 

 extent the overtures of the French composer ; though in this case, 

 as in every other of the kind, he improved whatever he touched. 



Some good observations on the position and office of the overture 

 will be found in an Essay by M. Fdtis, entitled ' La Musique mi 

 portee de tout le moude.' The author characterises Mozart's overture 

 to ' Zauberflote," as a " chef-d'oeuvre inimitable, qui sera eternellement 

 le modele des overtures et le de'sespoir des compositeurs." 



OWNERSHIP. [PROPERTY.] 



OXALAMYLIC ACID. [Ox&uc ACID.] 



OXALATES. [OXALIC ACID.] 



OXALHYDRIC ACID. [SACCHARIC ACID.] 



OXALIC ACID (HO, C 2 0, + 2Aq.) This acid was discovered by 

 Scheele, in 1776. It occurs in several plants, as in the wood sorrel 

 (Ojcalis aeetosf/la) hence the name oxalic, and in common sorrel 

 (Riimc.r acetoia). In the juice of these plants, and in the roots of 

 rhubarb, bistort, gentian, c., it is combined with potash ; in several 

 kinds of lichens, it is found in union with lime. It occurs as a 

 mineral compound in combination with oxide of iron, called ///,;- 

 bMtite. It is an ingredient also of several urinary calculi. 



Oxalic acid may be obtained by several processes : first, by decom- 

 posing the natural superoxolnte of potash, or salt of sorrel, by m< 

 acetate of lead, sulphuric acid, &c. ; but it is best obtained by heating 

 organic matter, such as sugar, potato starch, or even sawdust, with 

 nitric acid in a retort. Having been first obtained from sugar it re- 

 ceived the name of saccharine acid. Indeed most organic compounds 

 which contain much carbon and no nitrogen, may be converted into 

 oxalic acid by the action of nitric acid; hydrate of potash, in .some 

 coses, produces similar results, and this process applied to sawdust now 

 yields much of the oxalic acid used in commerce. When nitric acid 

 acts upon sugar or starch or sawdust, it is decomposed, and yi.-Ms 

 nitric oxide gas in great quantity ; the oxygen of the decomposed acid 

 uniting with the carbon of the vegetable matter, converts it into oxalic 

 acid : the crystals first obtained are to be dissolved in water and 

 re-crystallised to render them perfectly pure. 



Oxalic acid crystals are prismatic, colourless, and transparent ; the 

 primary form is a right rhombic prism. Their taste is extremely 

 sour, and they are vary poisonous. When dissolved in 200,000 Mm. 

 their weight of water, the solution reddens litmus paper. Exposed to 

 a dry air, oxalic acid effloresces, losing water of crystallisation ; it 

 dissolves in 15 parts of water at 50, and in 9 parts at 00; at 212 it 

 melts in its water of crystallisation; it is soluble also in alcohol, but 

 less so than in water. 



Oxalic acid is usually considered to be monobasic, but most of its 

 properties are those of a member of the dibasic series. 



No means have yet been discovered of forming oxalic acid by com- 

 bining carbonic oxide and carbonic acid ; but when oxalic acid is 

 heated with sulphuric acid, it resolves into these substances entirely, 

 ami in the proportions stated, the water which it contains combining 

 with the sulphuric acid. 



Oxalic acid contains water that cannot be totally expelled by heat ; 

 the acid, unless combined with a base, always retaining one equivalent. 



Oxalic acid is to a certain extent volatile, and Mr. Faraday has 



