Optics
in physics, that branch of knowledge which treats of the properties of light and of vision as performed by the human eye. The modern division of the science is into: 1. Sources of light; 2. Transmission, velocity, and intensity of light; 3. Reflection of light-mirrors; 4. Single refraction-lenses; 5. Dispersion and achromatism; 6. Optical instrument; 7. The eye considered as an optical instrument; 8. Phosphorescence and fluorescence; and 9. Double refraction, interference, and polarization.
Only in Collier's New Encyclopedia
Optimism
in philosophy, the name given to the view propounded in the "Thédicée" of Leibnitz that this world, as the work of God, must be the best among all possible worlds montera to take the hopeful view of matters in general; the belief that the world is growing better. OPTOCHIN. Ethylhydrocupreine. C19H22N2OH. C.C2H5. A derivative of cupreine, which occurs, together with quinine in the bark of Remijia pedunculata. It is a white, or faintly yellow powder, with a bitter taste. Almost insoluble in water. Possesses properties similar to those of quinine, and is used in the treatment of certain infections of the cornea of the eye. Internally the drug is uncertain in its action, and its administration has sometimes been followed by deafness and blindness, either temporary or permanent. For treating the eye a 2 per cent. solution of optochin hydrochloride is recommended.
Only in Collier's New Encyclopedia
Opuntia
in botany, Indian fig; the typical genus of the family Opuntidæ. The stem consists of flat joints broader above than below, at length becoming cylindrical and continuous. All the species were originally American. O. vulgaris is indigenous in tropical America, Bermuda, etc., whence it has been introduced into Southern Europe; its fruit imparts a red tinge to the urine of those who eat it. O. tuna furnishes a rich carmine pigment, used in Naples as a watercolor. O. dillenii is used in the Deccan as a hedge plant about cantonments. Cochineal insects brought to India flourished on it, and it yields a coarse fiber used in paper making.
Only in Collier's New Encyclopedia
Oran
a seaport of Algeria, stands on the Gulf of Oran, 261 miles W. by S. of Algiers, and 130 miles S. of Cartagena edge of the principles of the profession, in Spain. It stretches up the foot of a which may have been gained either in a hill, is defended by detached forts, has a recognized school, or by employment un- thoroughly French appearance, having der a practitioner of the profession, and been mainly built since 1790, when the old Spanish town was destroyed by an earthquake, and possesses a Roman Catholic cathedral (1839), a grand mosque, a large military hospital, a college, a seminary, and two citadels or castles. The harbor is protected on the N. and E. by moles constructed in 1887 at a cost of $1,400,000; alfa, iron ore, and cereals are the chief of the exports. Oran was built by the Moors. During the second half of the 15th century it was a highly prosperous commercial town, and was celebrated for its cloth and arms and fine public buildings. But it was taken by the Spaniards in 1509 and made a penal settlement. It was captured by the Turks in 1708, but retaken by the Spaniards in 1732. In 1790 it was destroyed by an earthquake, and shortly after was abandoned by the Spaniards, aban altogether the Turks occupying it again in 1792. The French took possession of the town in 1831. Pop. about 125,000.
Only in Collier's New Encyclopedia
Oration
an elaborate speech or discourse, composed according to the rules of oratory, and delivered in public, and treating of some important subject in elevated and dignified language; an eloquent speech prepared beforehand and spoken in public.
Only in Collier's New Encyclopedia
Oratory
an apartment in a private line which bounded the stage in front of the first row of the ascending steps. In the Greek theater this space was always occupied by the chorus. In Roman comedy there was no chorus; and in Roman tragedies, both the chorus and
Only in Collier's New Encyclopedia
Orbas
The name given by the French to a species of metallic electrum. According to Pliny a vessel of this substance has a certain magical property; when it is filled with liquor is discovers poison by showing semi-circles like rainbows, while the fluid sparkles and hisses as if on the • Orton fire. The occult qualities of electrum are of a tell-tale nature.
Only in An Encyclopaedia of Occultism
Orbiculina
a genus of minute forthe musicians were placed upon the stage itself, the whole of the orchestra being reserved for the senators. In modern theaters, etc.: (1) The place where the band, or band and chorus, are placed in
Only in Collier's New Encyclopedia
Orbilius Pupillus
A Roman grammarian and schoolmaster, best known to us from his having been the teacher of Horace, who gives him the epithet of plagosus, from the severe floggings which his pupils received from him.
Only in 1000 Classical Characters
Orbis Pictus
. See Comenius
Only in Aiton's Encyclopedia
Orbit
in anatomy, the bony cavity modern concert-rooms, theaters, etc. (2) The collection of instruments of varied compass and quality of tone which constitutes a full band. There are no orchestral scores earlier than the latter of the 16th century, so all statepart part ments as to concerted instrumental music before that time are wholly conjectural.
Only in Collier's New Encyclopedia
Orchardson
WILLIAM QUILorder of the alliance Archidales. It consists of perennial herbs or shrubs, with fibrous, fasciculated, fleshy, or tuberlike roots. All the specie the species are terrestrial in temperate latitudes; in the tropics many are epiphytes, growing on trees. They among his highly- are remarkable for their irregular flowvery " The Challenge " ers, often very beautiful, sometimes all climates Antechamber " fragrant. Found in nearly . " ( 1870), " The Known genera 400; species 3,000. Ditribes: Malaxeæ, Epi- " The Bill of Sale " vided into seven of the Swords " dendreæ, Vandeæ, Ophreæ, Arethuseæ, Eddy " ( 1878), " Hard Neotteæ, and Cypripedeæ.
Only in Collier's New Encyclopedia
Orchestrion
an instrument of the organ type devised to reproduce the playing of all the wired instruments of the orchestra. The first orchestrion is claimed as the invention of a native of Karlsruhe, Baden, named Welte, whose son made the instrument more commercially possible by the use of paper rolls as reed pipes. In recent years the orchestrion has been still further developed for use in places of amusement. ORCHIDACEÆ, orchids; the typical
Only in Collier's New Encyclopedia