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cornea upon the retina. The reflected rays from this image cause shadows of the blood-vessels on the retina, which in a darkened room will be projected outward through the nodal point of the eye, and are visible, greatly magnified, upon a favorably placed sheet or wall. The figures are made more distinct by moving the light to and fro. See Eye.

Purl. Mixture of ale, milk, spirits, and sugar.

Purlin. Horizontal beam connecting two main rafters or roof trusses, and serving to support the roof covering.

Purple, Tyrian. See Tyrian Purple.

Purple Emperor (apatura Iris). One of the richest

colored and largest butterflies. The expanse of wings is from 2 to 3± in., are strong and thick. It frequents the top of oak trees.

Purple Glow (red, or Rosy Glow). Broad colored disk from 5° to 50° above the horizon, over the sun, lasting a few minutes, and reappearing as the sun sinks.

Purple of Cassias. See

Gold Trichloride.

Purpura. Several conditions and causes other than violence produce extravasation of blood under the skin or mucous membrane. To these extravasations so proPurple Emperor (larva and pupalhown d,, general term Purbelow). pura is given. When the ex

travasation is due to an external injury, it is called an Ecchymosis. The treatment tends to correct the condition of the blood by strong diet and tonics, if low and the reverse if the condition is excited.

Purpuric Acid. C,HjNtO,. The free acid is unknown. Its ammonium salt is Murexide (q.v.).

Purpurln. C^H.O^ Trihydroxy anthraquinone; red coloring matter, present in the madder root, and prepared artificially by the oxidation of alizarine; orange needles; usually sold as an alizarine.

Purree, or Indian Yellow. Coloring matter made in India from the urine of cows fed on mango leaves. A single cow produces ab. 2 oz. a day. Often adulterated with chrome yellow. It consists mainly of the calcium and magnesium salts of euxantliic acid.

Purser. Officer having charge of pay, clothing and provisions on a vessel; in the navy displaced by paymaster.

Pursh, Friedrich Franoott, 1794-1820. Botanist. Flora America septentrionalis, 1814.

Purslane. Portulaca oleracea. Weed of the natural family Portulacacece, native of Europe, introduced into N. America; probably the worst weed in gardens in the U. S. The only successful method of combating it is to keep the ground stirred as often as the young plants make their appearance.

Purslane, Sea. Low, fleshy herbs of the genus Sesuvium, natural family Ficoidece, natives of the seacoast of the s.e. U. S.

Purslane, Water. Isuardia palustris. Low, smooth aquatic herb of the natural family Onagracece, native of the n. temperate zone.

Pursuivant. Member of the third or lowest office in the college of heralds.

Purus. River in S. America, flowing across Bolivia and Brazil, emptying into the Amazon ab. 100 m. s.w. of Manaos. Length ab. l",900 m.

Pus. Fluid formed in the process of suppuration. It is a breaking down of the material binding together the cell elements of a tissue, which liquefies and is mingled with the cells, along with others, usually the escaped white corpuscle of the blood. This condition is brought about by the action of certain forms of micro-organisms.

Puscv, Edward Bouterie, D.D., D.C.L., 1S00-1882. Hebrew Prof, at Oxford from 1828; one of the authors of Tracts for the Times (Nos. 18, 40, 67), and a leader in the movement which, to his displeasure, long bore his name; a man of retiring manners, ascetic piety, and deep learning, rather than of

original thought. His sermons had great influence. The Real Presence, 18,55-57; Minor Prophets, 1860-77; Daniel, 1864; An Eirenicon, 1865. See Tractarianism.

Puseyism. See Tractarianism.

Pushkin, Alexander Sergeivitch, 1799-1837. Russian national poet, eminent alike for epics and lyrics. The Oypsies, 1827; Eugene Onegin, 1828, tr. 1881; Poltava, 1829; Boris Oodunov, a tragedy, 1830. Some of his prose tales were tr. 1875, and his poems 1889.

Pustule. Small tumor or pimple containing pus. It is of inflammatory origin and usually has a reddened area surrounding the pustule.

Putamen. Shell of a peach-pit or similar vegetable structure. It is morphologically the endocarp of the fruit rendered dense and crustace^us, and contained in the sarcocarp, or pulpy layer.

Putnam, Frederick Ward, b. 1839. Director Peabody Academy of Sciences at Salem. Mass., 1867-76; curator Peabody Museum at Cambridge 1874; Prof, of Archaeology and Ethnology at Harvard 1886.

Putnam, George Palmer. 1814-1872. Grand-nephew of Israel; publisher in New York; author of several books of travel; founder of Putnam's Mag., 1853-56.—His son, George Haven, b. 1844, pub. Books and their Makers, 1896, and did much for international copyright.

Putnam, Israel, 1718-1790. General of the Revolution, distinguished for his courage and daring. He won renown at Bunker Hill and held commands in N. Y. 1776-77.—His cousin, RUFUS, served through the Revolution, founded Marietta, O.,

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1788, was a Judge of the Supreme Court of Northwest Territory 1789, Brig.-gen. under Wavne 1792, and U. S. Surveyorgen. 1793-1803.—A nephew. Gideon, 1764-1812, founded Saratoga Springs.

Putnam, Mary Traill Spence (lowell), b. 1810. Biographer of her father, Charles Lowell. Tragedy of Errors, 1862.—Her son, William Lowell, 1840-1861, was killed at Bull's Bluff, Va., and celebrated, with two cousins, by their uncle, J. R. Lowell, in a famous passage of the Harvard Commemoration Ode.

Putorlus. See Mustelid^e.

Putrefaction. Decomposition of organic matter under the influence of micro-organisms. The complex molecule is broken up by a succession of chemical changes through simpler forms of organic compounds into inorganic substances. Disagreeable odors are generated during the process.

Putrid Fever. See Typuus Fever.

Puts and Calls. See Options.

Putty. Mixture of whiting and oil, used by glaziers and


Putty-Powder. Binoxide of tin, used to polish stone, glass, etc., and in making enamel.

Putty-Root. See Adam-and-eve.

Putumayo. Left branch of the Amazon, rising in Colombia, Length ab. 950 m.



Purvis de Cha vannes, Pierre, b. 1814. French historical and decorative painter of high rank.

Puysegur, Antoine Hyacinthe De. Comte De, 1753-1809. French naval officer, in America 1778-79; Portuguese Vico-admiral 1795-1803. Cotes de St. Dominique, 1787.

Puzzles. Variety of ingenious devices, now used as means of diversion, in which the object is usually to unravel or disclose some hidden principle or idea by the aid of mechanical skill. Mechanical puzzles, which are very numerous, may all be referred to a few simple principles. Those now extant are practically represented by the well-known ball and cord, the wire ring puzzle, the Chinese geometrical puzzle, the arrangement of numbered blocks called the Fifteen Puzzle, and the American Pigs in Clover. Mechanical puzzles identical with those of Europe and Asia exist amon-r the aboriginal tribes of N. and S. America. No satisfactory explanation has yet been offered of their origin.

Piizzohiuo. Volcnnic earth found near Pozzuoli in Italy, which hardens when mixed with lime and water, forming a hydraulic cement; sometimes called Roman cement. Other varieties are found along the Rhine, near Andernach.

Pyal, FELIX, 1810-1889. French dramatist, in exile 1849-70 and 1871-80: condemned to death 1873 as a leader of the Commune; Deputy 1888.

Pycnidia. Sacs producing propagative bodies known as pycnospores, developed in certain ascomycetous Fungi.

Pycnodonts. Family of Mesozoic fish, having the mouth provided with a dense pavement of thick, round, flat teeth.

Pycnodus. Lepidoganoid fish, with large, round, flatcrowned teeth, covering broad jaws as with a pavement of from three to five rows.

Pycnogonida (podosomata or Pantopoda; Sea Spiders).

Group of Arachnids of small size, with four pairs of slender, long, and many-jointed legs, and, in the male, an accessory pair for carrying eggs. They have a conical proboscis, a rudimentary abdomen, and live among seaweeds. Recent students of this group place it apart from the other Arachnids in a class by itself.

Pycnospores. Propagative bodies of certain Fungi and contained in sacs called pycnidia.

Pydna. Town of Macedonia; scene of the defeat of Perseus by the Romans under L. ^Emilius Paulus 168 B.C., which ended the war.

Pye, Henry James. D.C.L.. 1745-1813. M.P. 1784: poetlaureate rrom 1790. Alfred, 1801.

Pyemia. Condition of the blood when poisoned by the presence of pus-producing micro-organisms; wherever these micro-organisms lodge, secondary abscesses are apt to form. The disease is very often fatal.

Pygiilium. Cauda) portion of a Trilobite.—Also, last segment of a Coleopter"s abdomen, left uncovered by the wingcases.

Pygmalion. King of Cyprus; lover of a maiden brought to life by Aphrodite from a statue.

Pygmies. 1. Fabulous race of dwarfs represented by Homer as dwelling on the shores of the ocean and attacked by cranes in the spring. 2. Undersized tribes of Africa, found and described by Du Chaillu, Stanley, and other travelers. Ancient writers located pygmy races beyond the limits of the then known world both northward and southward. Aristotle and Herodotus specifically located them in the heart of Africa: the facts that the undersized Bushmen show evidence of once having been spread over a wide area, and that the presence of a tribe of pygmies in Central Africa has been discovered by modern explorers, go to show that the ancient rumors were well founded. Many small people are found in Central America, w ith all their faculties, but there does not appear to be a tribe.

Pygobranchia. Group of tubicolous Annelids, characterized by having branchiae on the posterior segments only, as in Arenicola.

Pygobranchia (anthobranchiata). Group of Nudi


Pj cnogonum littoralc.

branchs, including the Doridce. These are slug-like Mollusks, crawling about upon seaweed. The gills form a circle surrounding the anus. There is a false mantle fold, and sometimes accessory gills.

Pygopodes (brevipexnati). Group of schizognathous Natatores. with small wings, useless for flight. There are two groups, lmpennes and Urinatores or Pygopodes proper.

Pygostyle. Plowshare-shaped bone at the end of a bird's caudal vertebral column, representing from four to six coalesced vertebras. It bears the rectrices or tail feathers.

Pylades. Cousin and friend of Orestes, whom he aided to avenge the murder of Agamemnon.

Pylailgilim. Conus arteriosus of the amphibian heart. It has a row of valves at each end, and one of the anterior valves extends longitudinally toward the posterior row.

Pyle, Howard, b. 1853. American author, chiefly of juvenile books, and illustrator. Men of Iron, 1891.

Pylon. Monumental gateway to an Egyptian temple. It is sometimes in the form of a truncated pyramid, but was


Pylon of Ptolemy Euergetes.

more typically a combination of two such structures connected. They were usually covered with hieroglyphic decorations. It is often used synonymously with propylon.

Pyloric Appendages (Cxc\h Appendages). Fingerlike diverticula of the digestive tract of fishes, situated at the beginning of the small intestine.

Pyloric Oca. 1. Finger-like processes from the duodenum of various fishes. 2. Large pouches from the stomach, one in each ray, of the star-fish.

Pym, JOHN, 1584-1643. One of the managers of Buckingham's impeachment 1626; recognized leader of Short Parliament 1640, and Long Parliament 1641; manager of the impeachment of Stafford and trial of Laud; presenter of the '"Grand Remonstrance"; chief of the five members whose attempted seizure brought on the Civil War; real head of the provisional government after the flight of Charles I. His ability was great, his influence enormous; his death, like that of Hampden, was a heavy loss to the nation.

Pynclion, William, 1590-1662. Founder of Agawam or Springfield, Mass., 1636; author of a book condemned as antiCalvinistic 1650: in England from 1652.—His son, John, 16211703, took his place, and was prominent in Mass. affairs.—A descendant, Thomas Riooles. D.D.. LL.B.. b. 1823. has b<-en prof, of Trinitv Coll. since 1854. and was its pres. 1874-83. Chemical Physics. 1869.

Pyogenic Bacteria. Pus-producing bacteria of wounds.

Pyramid. Polyhedron having n polygon as a base and the other faces triangles meeting at a common point called the vertex: right, when the base is a regular polygon: classified, according to base, as triangular, quadrangular, etc. The altitude of a pyramid is the perpendicular distnnce from the vertex to the plane of the base. The slant height of a right pyramid is the altitude of any one of its lateral faces.

Pyramid. Variety of the game of marbles, in which the

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limestone and granite. Its cost is variously est imated at from 150 to 600 million dollars. It has passages and interior chambers, the chief of which are called the King's Chamber and the Queen's Chamber; the masonry work of these is of the most perfect kind.

Pyramid Lake. In Nevada; drained by Truckee River. Area 203 sq. m.

Pyramid§, Battles Of. In these Bonaparte defeated the Mamelukes and made himself master of Lower Esypt, July 13 and 21, 1798.

Pyramus and Thisfoe. Hero and heroine of a story told in Ovid's Metamorphoses, and parodied in Midsummer Night's Dream.

Pyrargyrile. 3Ag,S4-Sl)jS3. Silver ore dark red in color and very brittle, found in Mexico, Nevada, and Idaho.

Pyrena. In Botany, seed-like endocarps of certain small drupes of several cells which ripen into a berry-like fruit, as in the Huckleberries.

Pyrene. C,«Hn>. Hydrocarbon contained in coal tar and obtained from the portion boiling above 360° C; solid, crystallizing in white plates.

Pyrenees. Range of high mountains traversing from e. to w. the isthmus connecting the Iberian peninsula with the mainland of Europe, and serving as a boundary between France and Spain. It is a comparatively narrow continuous range, having but two passes available for carriage roads. The core

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Pyrenocarps, or Perithecia. Sporocarps of the Pyreno


Pyrenolds. Minute, rounded bodies found in the chromatophores of certain Alga".

Pyrenomycetes. Order of Fungi belonging to the subclass Ascomycetes. having flask-shaped sporocarps open only at the neck. Most of the numerous species are parasites.

Pyrlicliometer. Instrument devised 1876 by Pouillet for measuring the intensity of the sun's radiation. It consists of a shallow circular box of thin copper or silver, blackened and filled with water, in which is immersed the bulb of a thermometer, the stem being partially inclosed in the tube which supports the box. At the lower end of this tube is a disk, equal


Ericsson's Pyrheliometer.

and parallel to the bottom of the cylindrical box. This is for receiving the shadow of the box, and enables the face of the latter to be directed accurately toward the sun. By noting the effect of the sun's rays on the temperature of the water during a given time, a measure of the power of the sun's heat is obtained. Herschel's actinometer was designed for the same purpose and is similar in construction.

Pyridine. C.HSN. Bpt. 117° C. Liquid, with a very disagreeable odor, present in bone-oil and obtained from it. It is a strong base. Hydrogen changes it to piperidine. Its constitution is


"I >


and from it numerous derivatives are formed by replacing the hydrogen atoms by groups. It is made by treating nicotinic acid with lime.

Pyriform. In Botany and Zoology, pear-shaped organs or organisms.

Pyriphlegothon. River of the lower world.

Pyrite. FeS,. Iron pyrites; a very common mineral, containing sulphur and iron, 53.4 per cent of sulphur, and 46.6 per cent of iron. It occurs in many different forms and diverse conditions. When crystallized the form is usually a cube or a pentagonal dodecahedron. It is a common accessory and harmful ingredient in mineral coal, in slate, and in sandstone. In mineral veins it is abundant as a gangue. and is frequently sufficiently auriferous to be treated as a gold ore. It has no value for the iron it contains, but is largely and increasingly utilized in the manufacture of sulphuric acid. The larjrest commercial producers of pyrite are Spain. Germany, and Mass. and Va., where it occurs in mass deposits of great extent and often carries enough copper to be of value as a source of that metal: 210,000 tons were imported into U. S 1892.

Pyrites. In the plural, a considerable number of metallic sulphides, allied in some of their properties to pyrite (iron pyrites), though differing widely in others. The most of these sulphides have value for the metal they contain, as copper, nickel, and cobalt.

Pyro Void*. If from two molecules of the ortho acid one molecule of water be abstracted, a pvro acid is formed; e.g., 2H,P04—H,,0=H,P,0,> pyrophosphor'ic acid.

Pyrocatechin. C,H,(OH),. Mpt. 104° C, bpt. 245° C. 1247

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Orthodihydroxybenzene. White crystals with a plienol odor, present in raw beet sugar, and prepared by the fusion of many resins with potash; commonly made by the decomposition of its methyl ether, GUAIACOL (q.v.).

Pyro-Electriclty. Electrification produced by heat. Certain minerals, when heated or cooled, become electrically polarized, or exhibit opposite electric properties in different parts. Tourmaline is a substance of this kind.

Pyrogallol, or Pyrogallic Acid. C„H3(OH):. White plates, melting; at 115° C; prepared by heating gallic acid and splitting out carbonic acid from it. It has a powerful affinity for oxygen, and is hence used as a reducing agent. It takes oxygen from silver salts, depositing the metal. It is used in photography.

Pyrolitriicous Acid. Impure Acetic Acid (q.v.), formed by the destructive distillation of wood.

Pyrolusite. MnO,. Manganese dioxide; one of the most important ores of manganese; worked extensively in manyparts of Europe and of the U. S.

Pyromagnctic Generator. Apparatus devised by Edison for utilizing the change of magnetism in a magnetic metal by heat for the purpose of generating an electric current. The metal to be heated is in the form of a thin sheet rolled up and surrounded by a coil of wire. The thin sheet he called an interstitial armature, since it connects the poles of a powerful electromagnet. When this armature is heated by the passage through it of a current of hot air it loses its magnetism, and when a current of cold air is sent through it, it gains it, this magnetization and demagnetization being used to generate a current in the coil.

Pyromancy. Divination (q.v.) by Are or the forms appearing in fire.

Pyrometer. Apparatus for measuring high temperatures above the limits of ordinary thermometers; used for furnaces, flues, chimneys, and hot blast ducts. There are three types. The first uses two bars of metals which expand unequally by heat, fastened together, and their free end so connected to a needle that the amount of curve given to the compound strip by a given heat shall move the needle through so many graduations. Objection to this type is that prolonged action of heat gives the bars a permanent change in length, which vitiates the readings. The second type depends on the different electrical conductivity of platinum wire at different temperatures. A battery cell and a galvanometer are required, and the cell which produces a given deflection of the needle when the conducting wire is cold deflects the needle a less amount when the wire is heated in the gas or flame to be measured. Heats are determined by fusion of metals or alloys of known character, or by

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other methods, and a table of deflections worked out for the particular instrument in question. The third type uses a ball or lump of some material of known weight and specific heat, which is placed in the material whose temperature is sought, and kept there till it reaches the same heat. It is quickly removed and dropped into a known weight of water, and it is observed by how many degrees the water is warmed. Then, if W = weight of water, w = weight of ball, T = original temperature of water, t = final temperature of water and ball. x = unknown temperature of heated ball, and c its specific heat, and radiation and evaporation be prevented, we have W X 1 X t — T = w X c X (x — t). in which x is the only unknown quantity. This is an exact method if a material is used whose specific heat has been determined exactly for the range of temperatures in question. For temperatures within the

yielding point of glass, the Air THERMOMETER (q.v.) can be

successfully used as a pyrometer.

Pyrope. Bright red garnet, much used in cheap jewelry; Bohemian garnet.

Pyroplione. Instrument devised by arranging a set of tubes of different lengths, which are made to sound by SinoIno Flames (q.v.).

Pyrophorous. Said of any substances which take fire from the rapidity with which they oxidize. If tartrate of lead is heated in a tube until the organic matter is charred and then poured into the air, it will take fire.

Pyrophosphate*. Derivatives of pyrophosphoric acid.

PyrophONphoric Acid. H,PaO,. Made by heating phosphoric acid to 200°-300° C. The pyrophosphates are formed by heating secondary phosphates.

Pyrosis. Abnormal condition of the stomach where there is a burning sensation accompanied by belchings of an acid or bitter fluid. It is a form of dyspepsia and may be relieved by moderate doses of some alkaline substance (baking soda, magnesia), but the cure depends upon removing the causes leading to the condition. See Heartburn.

Pyrosoma. See Ascidians.

PyroNulphurlc Acid. See Disulphuric Acid.

Pyrotechny. Art of preparing combustible compositions which give a pleasing effect when set on fire; of unknown antiquity, practiced by the Chinese from early times. These compositions are solid mixtures of combustible and oxidizing agents, to which some substances to modify the rate of burning and some to give color effects are added. The principal ingredient of pyrotechnic composition is mealed gunpowder, which burns slowly when well tamped, and evolves large volumes of gas. The decorations placed in paper shells, Roman candles and rockets are principally stars, serpents, niarrons. gold rain, and rain of fire; these are formed from niter, sulphur, mealed powder, charcoal, metallic filings and the salts of various metals for color effects, such as sodium for yellow, calcium for red, strontium for crimson, barium for green, and copper for green or blue: iron and steel filings give sparks. Formerly the construction of fire-balls, carcasses, rockets, port-fires, slow and quick match, and other military pyrotechnics was a branch of military instruction, but having recently lost much of their importance, due to the introduction of electricity, they are now for the greater part practically obsolete.

Pyroxene. Mineral closely allied to amphibole in almost all respects. The name includes several varieties of aluminous and nou-aluminous anhydrous silicates of calcium, magnesium, and iron. Among these varieties the most important are diallage and augite. which are common ingredients in crystalline rocks.

Pyroxylin. Usually, the explosive hexa-nitrate. See Nitrocellulose and Gun Cotton. Pyrrha. Wife of Deucalion, the Noah of Greek legend. Pyrrhic Dance. Native in Crete; performed by Spartans

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drown the cries of the infant Zeus. It was a mimic fight, intended to show the art of attack and defense.

Pyrrho, Of Elis, ab.360-ab.270 B.C. Greek philosopher of the Skeptical school, who denied all knowledge of the nature of things.

Pyrrhonism. Absolute skepticism, named from Pyrrho, who maintained that we cannot know that we know anything; uncertainty attaches to every proposition the human mind can frame.

Pyrrhotite. FenSn+,. Magnetic pyrites; compound of iron and sulphur, in which the value of n ranges from 5 to 16. It often contains enough nickel to be of value as a nickel-ore.

Pyrrhus, 318-272 B.C. King of Epirus 307, expelled 302, restored 295; in Italv, as ally of Tarentum, warring with Rome 280-278, and in Sicily, with Carthage, 278-276; defeated by Dentatus near Beneventura 275; conqueror of most of Macedonia 274; at war with Sparta 272; killed at Argos by a tile thrown by a woman.

Pyrrol. C4H4NH. Basic liquid, bpt. 126° C; present in coal tar, but usually prepared from bone-oil. It has an odor like that of chloroform. It is thus constituted,


and the ring C,N is called the pyrrol ting.

Pyruvic Acid. CH,.CO.COOH. Bpt. 165° C. Ketone and acid; liquid, strong acid, produced by heating tartaric and similar organic acids.

Pythagoras, 582-504 B.C. Greek philosopher, founder of the Pythagorean school and of a republic at Crotona, Italy, which treated its citizens as brothers and equals. He applied mathematical conceptions of numbers to metaphysics, was one of the (irst to maintain the immortality of the soul in the form of metempsychosis, and was ascetic in the theory and practice of morals. He is supposed to have discovered the

famous proposition that "the square on the hypotenuse of a right triangle is equivalent to the sum of the squares on the other two sides."

Pythia. See Pythoness.

Pythian Games. Festival in honor of Apollo and Artemis, celebrated originally at Delphi once in 8 years, later in a plain near by every 4 years, alternating with the festiv;#l at Olympia; so "called" from 581 B.C., when gymnastic contests were added to the musical; managed by the Amphictyons after 346 B.C. Musical anil artistic contests were always the most prominent feature; the prizes were a chaplet of laurel, a symbolic palm-branch, and a statue in the plain where the contests were held. They lasted till 400.

Pythias. See Damon.

Python. Serpent which sprang from the mud left by the deluge of Deucalion, lived in the caves of Mt. Parnassus, and was slain by Apollo, who founded the Pythian games to commemorate his victory.

Python. See Peropoda and Aqlyphodonta. Pythoness. Priestess of Apollo at Delphi, through whom the oracle gave responses.

Pythonomorpha (sea Serpents). Group of Saurians of the Cretaceous period, represented by fossils from N. J., Aln., Kansas, etc. The body was serpentine in shape, the limbs small, the teeth and jaws adapted for swallowing large prey whole. They lived in the warm seas that covered the e. plains of the Appalachian and Rocky Mt. systems. Members of the genus ClidaxteH ranged from 12 to 40 ft. in length, those of Mosasaurus reached a length of 80 ft., and of Liodon even more, perhaps 100 ft.

Pyx. 1. In the R.C. Church, name given to the box in which the host is kept. 2. Box in which coins are kept of each successive coinage, these coins to be examined by experts as to their accuracy in weight and Oneness. The examination thereof is called the trial of the pyx, and takes place at the Philadelphia mint the second Wednesday of February, annually.

Pyxis (pyxidium). Capsular dry fruit which opens by the top falling away as a lid, the dehiscence being circumscissile, as in the Henbane and Plantain.

Q. S. Abbreviation for quantum suflftcit (as much as needed), used in writing medical prescriptions.

Quaekenbos, George Payn, LL.D., 1826-1881. American author of text-books, as is his sou, John Duncan, b. 1848, prof. Columbia 1884.

Quaekenbush, Stephen Platt, U.S.N., 1823-1890. Lieut. 1855, Lieut.-commander 1862; distinguished on the Atlantic coast in the war; Commodore 1880, Rear-admiral 1885.

Quack Grass. Agropyron repens. One of the worst weeds of cultivated grounds. It spreads by seed, but more rapidly by its vigorous underground stems, and is eradicated only by the most vigorous and thorough culture. In grass fields it is not so troublesome, as it is nutritious and cattle are fond of it. It is also known as couch, switch, and quitch grass.

Quadragesima. First Sunday in Lent; name now little used.

Having four angles. A complete quad


Quadrangle of Arundel Castle, England.

rangle is one each of whose sides intersects the other three.— an open space or courtyard having four sides and quite

Public buildings, such 3 usually planned in this

or nearly surrounded by buildings.

as castles, colleges, city nails, etc., ai way.

Quadrant. Arc of 90°; one-fourth of a circle. In trigonometry the circle of reference is divided by horizontal and vertical diameters into four quadrants: the first is that above the horizontal and to the right of the vertical diameter; the others are numbered to the left, second, third, fourth.

Quadrant. The dimensions of inductance being simply a length, the unit in the C.G.S. system is a centimeter. In practice a unit 1,000,000,000 times as large is chosen and called a quadrant, this being the number of centimeters in a quadrant of the earth.

Quadrant. See Octant.

Quadrantal Deviation. Deviation from its normal

position produced upon a magnetic needle by horizontal masses of iron or steel magnetized inductively by the earth. The phenomenon occurs on shipboard in the case of the compass needle. In swinging the ship round there are four positions in which the influence would be a maximum, and four in which it would be a minimum: hence the name.

Quadrantal Pendulum. Body moving about an axis according to the same law with reference to a quadrant on each side of its position of equilibrium, as a common pendulum with reference to a half circle on each side.

Quadrantal Triangle. In Spherical Trigonometry, triangle having one side a quadrant. Such triangles are solved by their polar right triangles. If each side be a quadrant, the triangle is called triquadrantal.

Quadrate. Bone to which the lower jaw is articulated in vertebrates below mammals. In the latter this bone has become the incus, or middle bone of the three auditory ossicles, and the jaw articulates directly with the skull.

Quadratic Equation. One involving the second power of the unknown quantity and none higher. A quantic may be quadratic in respect to one variable and not so for another. A complete quadratic has both first and second powers of the unknown.

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