OPPENHEIM 



is said to be the ol.|-,i cliurob in 

 U|i|>er Silcnia. There are a semin- 

 ary for teachera, and a Urge 

 hospital. Oppeln manufactures 

 cement, cigars, machinery, cutlnv. 

 and there are breweries and lime 

 kilns. Its trade, supported by a 

 i-li.imlx>r of commerce, consists 

 i lui-llv of grain and cattle. Devas- 

 tated in 1260 by the Tartars, it 

 passed in 1532 to Austria, but in 

 1742 became part of Prussia. Pop. 

 34,000. 



Oppenheim. Town of Heaae- 

 Diirinstadt, Germany. It is on the 

 left bank of the Rhine, 20 m. S.S. K. 

 of .Mainz. The Gothic church of S. 

 < '.iili.-rino contains the tombs of 

 the Dalberg family (q.v.). Oppen- 

 heim, which has a trade in wine, 

 was taken by the Swedes in 1031, 

 and by the French in 1689, 1792, 

 and 1794. Near by arc ruins of an 

 llth century fortress. Pop. 4,000. 

 Oppenheim, EDWARD PHILLIPS 

 (b. 1866). British novelist. Edu- 

 cated at Iveicester, he became 

 known as a 

 writer of popu- 

 lar fiction, and 

 a frequent con- 

 t r i b 11 1 o r to 

 magazines. His 

 novels of mys- 

 tery and sen- 

 sation are 

 marked by 

 ingenuity o f 

 construction 

 Ruueii an( j dramatic 



quality. They include The Amaz- 

 ing Judgment, 1897 ; As a Man 

 Lives, 1898; The Mysterious Mr. 

 Sabin, 1898 ; The Master Mummer, 

 1905; The Mischief Maker, 1913; 

 Mr. Grex of Monte Carlo, 1915; 

 The Double Traitor, 1918; The 

 Great Impersonation, 1920. 



Oppenheimer, SIR BERNARD 

 (1866-1921). British merchant. 

 Born Feb. 13, 1866, he became in- 

 terested in the diamond industry 

 in S. Africa. About 1917 he started 

 factories where disabled soldiers 

 could find employment at diamond 

 cutting. He made his first experi- 

 ments in Brighton, and, the under- 

 taking proving successful, branches 

 were opened at Cambridge, Fort 

 William, and Wrexham, and the 

 business was made into a limited 

 company. Oppenheimer was created 

 a baronet in 1921. He died June 

 13, 1921. 



Opportunism. In general, the 

 capacity of seizing a favourable 

 opportunity. In a narrower sense, 

 the regulation of one's course of 

 action by circumstances rather 

 than principles, often resulting in 

 the sacrifice of the latter to the 

 former. The name opportunists is 

 especially applied in French history 

 to the followers of Gambetta, the 



ELPhillipsOppenhei 

 British novelist 



S895 



moderate republicans, who limited 



1 1 i-i i political aim* to practicable 

 measure*. 



Opposition. In I'.ntiili |M.ht|. ,. 

 the name given to the party that 

 U out of power and that exUt* 

 mainly for the purpose of critic-wing 

 the party in power, and, if possible. 

 supplanting it An opposition is an 

 essential part of parliamentary 

 government, but in its modern 

 sense the word was first used in 

 1826 by John C. Hobhouae, after- 

 wards Lord Broughton. Gradually 

 it came into general use, and tli- 

 opposition became a regular part 

 of the machinery of government, 

 its leaders having recognized places 

 and precedence in both Houses of 

 Parliament. The word used in this 

 sense passed into all parliaments 

 of the British Empire, and into 

 some foreign legislatures. In Great 

 Britain until 1919 the Liberal and 

 Unionist parties and their pre- 

 decessors, Whigs and Tories, had 

 shared alternately the duties of 

 the opposition, but in that year, in 

 consequence of the virtual disap- 

 pearance of the official Liberals at 

 the general election of 1918, the 

 Labour party assumed the role of 

 official opposition. See Conserva- 

 tive ; Liberal ; Unionist. 



Opposition. In astronomy, 

 the position of one heavenly body 

 with respect to another when dif- 

 fering from it in longitude by ISO 3 . 

 The earth and another planet are 

 in opposition when they and the 

 sun are in a straight line. 



Oppy. Village of N. France. 

 In the dept. of Pas-de-Calais, 4 m. 

 N. of the river Scarpe and about 

 the same distance S.E. of Vimy, 

 it was the scene of furious and 

 continuous fighting during the 

 battle of Arras in April- May, 1917, 

 and just before the opening of the 

 battle of Le Cateau (/.<.) in Oct., 

 1918. A fortified post in the Hin- 

 denburg lane, it was repeatedly 

 attacked by the British advancing 

 from Arras. It was taken and held 

 in June, 1917, but lost again in 

 the German advance of the spring 

 of 1918. See Arras, Battles of. 



Ops. In Roman mythology, 

 wife of the god Saturn, and 

 patroness of agriculture. The 

 Romans identified her with the 

 Greek Rhea (q.v.). 



Opsonin . Term used in bacteri- 

 ology to explain the effect which 

 normal human blood serum has 

 upon the destruction of bacteria 

 in the blood by leucocytes. Experi- 

 ment has shown that there are sub- 

 stances in the blood scrum which 

 in some way or other so modify 

 bacteria as to render them more 

 easily attacked and devoured by 

 the leucocytes. This change is 

 known as the opsonic effect, and 



OPTICIAN 



the Nutwtances in the serum which 

 render the bacteria more easily 

 destructible are called opsoniru. 

 By a highly technical bacteriologi- 

 cal process an exact standard of 

 the power of serum in this respect 

 can bo arrived at, and the wrum 

 if OIK- iiKlm.lti.-il niiiipared with 

 that of another before and after 

 treatment. This standard is known 

 as the opsonic index. See, Phago- 

 cytosis. 



Optative (Lat. optare, to wish). 

 Name given to a form of the verb 

 expressing a wish or desire. Lake 

 the subjunctive, it marks the action 

 as a conception, as something 

 which may or may not happen, 

 not as an actual fact. Its use is 

 most clearly marked in Greek. 



Optical Glass. Variety of glass 

 used in the manufacture of lenses 

 for optical instruments. The first 

 essential characteristic of optical 

 glass is that it must be homo- 

 geneous, and this has made it one 

 of the most difficult glasses to pro- 

 duce to perfection. Guinand in the 

 18th century made the first attempt 

 at homogeneous flint glass manu- 

 facture by constantly stirring the 

 molten glass, and in 1824 the 

 Royal Astronomical Society ap- 

 pointed a committee to consider 

 the question of optical glass making. 



The researches of Abbe and 

 Schott at Jena, however, on the 

 effect of various oxides on vitreous 

 fluxes led to the invention of Jena 

 optical glass, now in general use. 

 The old varieties of optical glass 

 consisted mainly of silicates, while 

 modern glass contains many oxides, 

 e.g. those of barium, zinc, alu- 

 minium, etc., silicates and boric 

 anhydride, which enable lenses of 

 remarkable purity and suitable opti - 

 cal qualities to be manufactured. 



The glass has to go through a 

 number of processes, e.g. moulding 

 and annealing, and the high pro- 

 portion of the finished glass which 

 has to be rejected, on account of air 

 bubbles, fractures, and other de- 

 fects, makes the glass actually fit 

 for optical purposes very expen- 

 sive. Not more than one fifth of 

 the total glass manufactured for 

 optical purposes is actually used, 

 as a rule. See Glass ; Telescope. 



Optician. One who makes, or 

 who deals in, optical glasses and 

 instruments. There is, in tin 

 United Kingdom, no legal status 

 for opticians, and the term is often 

 used by those who sell spectacles, 

 but more properly it indicates one 

 who, having passed the necessary 

 examinations, is qualified by the 

 Worshipful Company of Spectacle 

 Makers, or by the British Optical 

 Association. The Spectacle Makers 

 Company holds a Royal Charter, 

 and grants successful candidates 



