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QUINIDINE-QUOIN

Quinidine. Mixture of cinchona alkaloids, found in trade.
The commercial sulphate is largely cinchonidine sulphate.
Some consider that an alkaloid called quinidine is present.

Quinine. C20HN,O,,3H2O. Intensely bitter base, pre-
pared from Cinchona bark; white needles, mpt. 177° C. The
common salts are the sulphate and chloride, both used as feb-
rifuges. See PERUVIAN BARK.

Quinisext Council. At Constantinople 692; called as a supplement to the 5th and 6th councils 555 and 680; not recognized by R.C. Ch.

Quinnat. See ONCORHYNCHUS.

Quinoa. Chenopodium quinoa.
family Chenopodiaceae, native of Peru, extensively cultivated
Herb of the natural
in the Andes for its seeds, which when ground into meal are
an important article of food.

Quinoline. C,H,N. Bpt. 236° C. Liquid, of characteris-
tic odor and basic properties; present in coal-tar and produced
by the distillation of many bases, such as quinine; prepared by
the action of sulphuric acid and glycerin upon a mixture of
aniline and nitrobenzene; used in the production of certain
dye-stuffs.

Quinoline Blue. See CYANINE.

Quinoline Red. C,,H,,N,Cl. Product of the action of benzotrichloride upon a mixture of quinaldine and a chinoline; dark brown needles, soluble in hot water; used in photography.

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Quinoline Yellow. C,,H,,NO,. Yellow product, prepared by the action of phthalic anhydride and zinc chloride on quinaldine; soluble in alcohol, but not in water; used to color varnishes and lacquers. The water-soluble quinoline yellow is produced by the action of sulphuric acid upon the compound described above. It is a sodium salt of a sulfo acid, and is used in dying wool.

Quinone. C,H,O,. Mpt. 116° C.

prisms of a pungent odor, soluble in alcohol and ether; made
Yellow needles or
by oxidizing hydroquinone. As a class the quinones are mainly
yellow crystalline substances, obtained by the oxidation of para-
dihydroxy compounds.

Quinquagesima. Sunday before Lent.

Quinquefoliolate. Compound leaves composed of five leaflets, as the Virginia Creeper.

Quinquejugate. Pinnately compound leaves with five pairs of leaflets.

Quinquelocular. In Botany, ovaries or pericarps with
five cavities.

Quinqueremes, Ancient vessels with five banks of oars.
See TRIREME.

Quinsy. Inflammation of the tonsils, causing great dis-
tress and discomfort. Persons having one attack are subject
to repetitions. It usually forms an abscess, which, when lanced
or spontaneously ruptured, brings prompt relief.

Quintain. Post with a cross-bar from which hung a bag of sand and a board, to be tilted at by horsemen; sometimes

Quintain.

in other forms. The object was to strike the board at such
speed as to be well past befor

The

1

French weight was ab. 108 lbs., the modern weight is eq
Quintal. 100 wt., mostly for weighing fish.
to 100 kilograms, ab. 220 lbs. In Newfoundland 112 lbs.
biographer, imprisoned 1814-20; senator
Quintana, MANUEL JOSÉ, 1772-1857. Spanish poet a
celebres, 1807-34.
1833. Espand

Episcopal Church 1855; Bp. of Tenn. 1865.
Quintard, CHARLES TODD, M.D., LL.D., b. 1824. Pr
Memphis Medical College 1851; took orders in the Protesta

Quintic. Quantic of the fifth degree; as, ax'+bx'y+cx' +dx'y'+exy+y'.

Quintilian (MARCUS FABIUS), ab.35-ab.96. Latin writ on Eloquence and Oratorical training. His chief work is Institutione Oratoria Libri XII.

Quintus Curtius Rufus, 1st cent. Latin biograph of Alexander the Great. His book is unreliable: most of survives.

Quintus Smyrnæus, 4th cent. Posthomerica, in 14 books, completes the point where the Iliad leaves it. tive.

Greek epic poet, whos the story of Troy from His style is not attrac

Quipu. Means of conveying instructions, commands, and records by knotted cords, used in Peru before the conquest. Quirinal. One of the hills of Rome, n.e. of the Forum. Quirinus. See ROMULUS.

Quirites. In ancient Rome, burgesses, or warrior-citizens sometimes citizens as opposed to soldiers. Mommsen says the word originally meant lancemen: others derive it from Cures, a Sabine town incorporated with Rome.

Quitch Grass. See COUCH GRASS and QUACK GRASS. Quit-Claim. Conveyance of such title as the grantor has, without covenants of any kind.

Quitman, JOHN ANTHONY, 1799-1858. Chancellor of Miss. 1828-34; Brig.-gen. U.S.A. 1846; highly distinguished in the war with Mexico; Gov. of Miss. 1850; M.C. from 1855; advocate of extreme Southern ideas, anticipating 1851 secession and the Confederacy.

Quito. Capital of Ecuador; on e. slope of the volcano Pichincha, 9,300 ft. above the sea; subjected to the Incas ab.

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Market Scene in Quito.

1470; taken by Spaniards 1534.
destroyed ab. 40,000 persons; another, March, 1859, ab. 5,000.
An earthquake in Feb., 1797,
Pop. ab. 35,000.

Quit Rent. Certain established rents of the freeholders, which when paid make the tenant quit and free of all other services.

Quittor. Ulcer or abscess of the foot of a horse, due to a nail prick, thrush. or bruise which

1254

QUOIN-RACCOONS

angles of walls or in the frames of openings, in connection with rubble or brick-work, in order to secure a true line, or to strengthen the wall.

Quoin. Corner of a masonry wall projecting beyond the two faces, so as to give the appearance of a corner pier. Quoits. Game is played by any number, usually even, It consists of pitching round metal disks, convex on the top sides being chosen. and flat on the bottom, with an aperture in the center, at a peg called a hob, set in the ground and projecting therefrom ab. 24 in. There are two of these hobs, set 18 or 21 yds. apart, smaller for large or Hob. quoits. The players The side stand at one hob while pitching for the other.

Quoits.

having one, two, or more quoits nearer the hob scor cordingly. The game was probably derived from "thr the discus" of the Greeks and Romans.

T. B. Re Quorum. Number of members of a body whose pr is requisite for the transaction of business. Speaker of the House, ruled, Sept. 1890, that a quoru determined by the number present, whether voting d It had previously been ascertained by the votes cast.

a

Quotidian. That which takes place every day. Qu fever is an intermittent, the paroxysms of which occu day. It may be simple, double or triple, according number of paroxysms occurring in 24 hours.

Quotient. Result of division; expression showin many times one quantity is contained in another.

Quo Warranto. Old common-law writ to inq what authority a person or corporation held an office cised a franchise.

Ra. Ancient solar deity of Egypt, worshiped especially at Heliopolis.

Raabe, WILHELM. b. 1831. German humoristic novelist. Horacker, 1876; Der Lar, 1889.

R

Rabanus, or Hrabanus, MAURUS, ab. 776-856. Abbot of Fulda 822-842, Abp. of Mainz 847; eminent for learning; opponent of transubstantiation and predestination.

Rabat. Seaport of Morocco, now much impaired; on the Atlantic; noted for its carpets and other manufactures. Pop. ab. 26,000.

Rabaud, CHARLES HECTOR, 1711-1764. Writer on the laws, etc., of the French West Indies. His work, 6 vols., 1761-65, is of historical value.

Rabbis. Jewish teachers of the Law; authors or compilers of a large body of literature, of which the most important examples are the Mishnah and Talmud, with sundry commentaries upon them.

Rabbit. See LEPUS and HARES.

Rabelais, FRANÇOIS, ab.1495-1553. French humorist, origi-
His Gargantua, 1532, burlesqued
nally a Franciscan monk.
familiar legends, and was continued in a higher vein in Panta-
gruel, 1535-63, whose breadth and freedom of thought pro-

Rabenhorst, GOTTLOB LUDWIG, 1806-1881. Germa ist; prolific writer.

Rabies. See HYDROPHOBIA.

Rabourdin, HENRI ÉTIENNE, 1711-1764.

writer on America.

Frenc

Assyrian officer, herald of Senn Rabshakch. invasion of Judea 702 B.C.; mentioned Isa. xxxvi.; title rather than name.

Rabulas, d. 435. Bp. of Edessa; strict promoter doxy. Some of his works survive, and were pub. 1865 Rabutin. See SÉVIGNÉ.

Racahout.

Arabian substitute for chocolate; a tion of roasted acorns powdered with sugar and arom Racan, HONORAT DE BUEIL, MARQUIS DE, 1589-1670 poet and Academician.

Raccoons. Procyon lotor, the common "coon," in all woods of U. S. It is 3 ft. long, including tail

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Francois Rabelais.

voked much criticism: it bears marks of learning as well as of
riotous mirth. He held benefices, practiced medicine, made
almanacs, and was a more reputable person than the legends
represent him.

Raccoons (Procyon lotor).

ly a foot. Its fur is extra dense, gray in color n with a black stripe across the face. It walks eit GOTTLIEB WILHELM, 1714-1771. German satiri- black, and tail ringed. The body is stout; the muzz

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RACE-RADBERTUS

grade or digitigrade. It is fond of eggs, chickens, green corn,
and fish, and souses ordinary meat in water before swallow-
ing it. It can be tamed. Its cunning is proverbial among
hunters. It nests in trees or in holes in banks. Three to six
young are born at a time. California has the Black-footed
Raccoon (P. hernandezii), and in S. America is P. cancrivorus,
the Crab-eater. See PROCYONIDÆ.

Race, CAPE. Southeast point of Newfoundland.
Raceme. Elongated, indeterminate flower-cluster, hav-
ing the flowers borne on pedicels of about equal length, as in
the Lily of the Valley and Locust.

Racemic Acid. Optically inactive form of TARTARIC
ACID (q.v.).

Racemose.

Rack. Toothed wheel whose radius is infinity or pitch surface is a plane (see GEAR WHEELS); useful to form rotary into reciprocating motion; also fixed a toothed surfaces with finite radius. upon which a pinion for moving drawbridge spans, turntables, etc.

Rackarock. Sprengel explosive, 79 per cent pota chlorate and 21 nitrobenzene for maximum intensity, under water is 1.08 times that of No. 1 dynamite. It was to blow up Flood Gate in N. Y. Harbor. It will explo percussion.

Rackets. Later variety of game with bat and bal rived from Tennis (see COURT TENNIS). A racket-court m from 50 to 80 ft. long, and 30 to 40 wide, with a very high and a back wall of less height, having at its top a galler

Flowers arranged in racemes, or forms of spectators. Running along the front wall, which is us flower-clusters resembling racemes.

Racemose Vesicles. Branched water-sacs that project
upward from the circumoral ring into the body cavity of a
star-fish. They are nine, one for each radius and interradius,
except the one occupied by the Stone Canal.

Racemulose. Diminutive of racemose.
Races of Men. See MAN.

Rachel, Daughter of the Mesopotamian Laban, wife of
his nephew Jacob; mother of Joseph, and ancestress of the
tribes of Ephraim, Manasseh, and Benjamin.

Rachel (ÉLISA RACHEL FELIX), 1820-1858. French tragic actress of highest rank, born a Swiss Jewess; famous from 1838; unsurpassed, if not unequaled, in passionate parts, as Phèdre and Marie Stuart.

Rachidian Teeth. Those of the rachis or central row
of the lingual ribbon (radula) of the Gastropods.

Rachilla. In Botany, axis of the spikelet in Gramineæ.
Rachis, or RHACHIS. Axis of elongated flower-clusters;
also the midrib of compound leaves, especially those of ferns.
Rachitis, or RHACHITIS. See RICKETS.

Racine. Capital of R. co., Wis., on Lake Michigan; founded
1836, chartered 1848; seat of R. Coll., established by P. E. Ch.
1852. It has considerable manufactures, and a good lake trade.
Pop., 1890, 21,014.

Racine, JEAN BAPTISTE, 1639-1699. French tragic dramatist of the first rank; Academician 1673. His masterpieces are Iphigénie, 1675; Phèdre, 1677; Esther, 1689, and Athalie, 1691. Other plays are Andromaque, 1667; Britannicus, 1667; Bérénice, 1670; Bajazet, 1672: Mithridate, 1673; and a comedy, Les Plaideurs, 1688.-His son LOUIS, 1692-1763, wrote Religion, 1742, and other serious poems.

Racing. The record for pacing one mile was lowered to 1.59 seconds by Star Pointer and the double team record to 2.09 seconds by John R. Gentry and Robert J. in 1897. See HORSERACING.

Rack. In Ore-dressing, form of apparatus in which small charges of pulp are separately treated on a smooth inclined surface, the poorer portions running to waste and the richer being washed off at frequent intervals.

Rack. Machine of torture used from ancient times to force confessions; wooden frame on which the accused lay,

black, is a board or balk a little over 2 ft. high, and a v line called the cut line is traced across this wall nearly from the floor. The floor is of level asphalt and divided

Front wall

A

B

Back wall

D

sections (see diagram).

game is begun by on the players serving the against the front wall a the white line so tha shall on the rebound st in either C or D, accor as he serves from Bo The opponent then ret it either on the fly vo or first bound, so tha strikes the front wall ab the lower line.

A and B. The server m have one or both feet in one of these spaces w serving.

C and D. The spaces which the server must s the ball on the rebound fi the front wall. If he ser from B, the ball must st in C; if from A, in D.

Rack Railroads. Those having rails with pinions wh engage in cogs on the locomotive wheels, so as to permit ascent of steep grades. In the Abt system there are th series of racks so alternating that a tooth of the whee always between two pinions. In the Riggenbach syster series of horizontal bars like rounds of a ladder is used. F tion clutches are also employed as an additional safegu

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Rack Railroad.

Rack railroads have been built on Mt. Pilatus in Switzerl and up many other mountains of Europe. Pike's Peak, Col ascended by a rack road on the Abt system, its length be 84 miles and its rise 7,600 ft.; the locomotives weigh 25t and push two loaded cars up the grade at a speed of a miles per hour. Mt. Washington. N. H., is ascended by a r having a maximum grade of 1,980 ft. per mile, a rack ra simpler type than the Abt being used.

Rack Rent. Rent whose amount is determined by o competition in a country where land is in demand, instea being either of a customary amount or settled by priv arrangement.

Radbertus, PASCHASTUS ah 700 ORE

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1256

RADCLIFFE-RADIATION

Radcliffe, MRS. ANN (WARD), 1764-1823. English romanHer Mysteries of Udolpho, 1794, and other wild tales were long popular.

cer.

Radcliffe, CHARLES BLAND, M.D., 1822-1889. medical writer. Epilepsy, 1854.

stem, which is pinned to the former at one point, and v
one end of the eccentric rod travels in a closed curve, su
The vari
a circle or an ellipse, another point is compelled by lin
slides to a motion in an open or closed curve.
English in cut-off and the reversal are made by varying the
which the axis of this last curve makes with the mean 1
direction of the eccentric rod.

Radcliffe, JOHN, 1650-1714. London physician of eminent popularity; M.P. 1713.

Radcliffe College. At Cambridge, Mass.; was chartered 1893. It grew out of "A Society for the Collegiate Instruction of Women," organized 1878, and was known for a time as The Harvard Annex, instruction being given by some of the Harvard faculty. Its degrees are signed by the Pres. of Harvard. It has 90 instructors, 358 students, and a library of 9,734 vols.

Raddi, GIUSEPPE, 1770-1829. Italian explorer in Brazil 1817; writer on its cryptogams and plants, 1822-25.

Radetzky, JOHANN JOSEPH, GRAF VON, 1766-1858. Austrian officer, field-marshal 1836; distinguished in the wars against Napoleon, and 1848-49 in n. Italy, where he suppressed the risings and was Gov. till 1857.

Radford, WILLIAM, U.S.N., 1808-1890. Commander 1855, Commodore 1863, Rear-admiral 1866; prominent in the attack on Fort Fisher Dec. 1864, and its capture Jan. 1865.

Radial Canals. Tubes that radiate from the central stomach, to open into a circular canal at the margin of the umbrella of Medusa.

Radial Drill. Form of machine tool for drilling, in which the revolving spindle is carried upon a horizontal arm or radius, which swings around an upright column. The spindle carriage can be traversed horizontally along the radius, to adjust the point of the tool over the center of holes in a heavy

Radial Drill.

work which it would be hard to locate under a fixed spindle.
Moreover, the spindle can operate easily on end of work too
tall to stand under ordinary upright drills. Sometimes, though
rarely, the radius has horizontal adjustment on the column.
See DRILL.

Radial Plates (or RADIALIA OF CRINOIDS). See BASAL
PLATES.

Radial Symmetry. Displayed in radiated animals, as
jelly-fishes, star-fishes, and coral polyps. Their bodies are
divisible into a number of similar segments. In some corals
and in ctenophores there are two kinds of segments, one sort
being situated at right angles to the other; such symmetry is
biradial. The radial axes through the center of each sector
are known as perradii; those that separate the sectors are in-
terradii; those that lie on each side of a perradius are adra-
dii, while those near interradii are subradii. See ANTIMERES,
PARAMERES, and ACTINOMERES.

Radial Valve Gear. Type of mechanical motions, to which the Joy. Brown, and Marshall gears belong, for operating the valves of steam engines, and permitting a variable of the direction of motion of engine. The sight angles to the valve

Radian. Circular arc, equal in length to the radi the circle; used as the unit in arcual or "" measure of and angles. The radian-57° 17′ 44.8" in degree measure ratio to the semi-circumference is 3.14159+(=π).

Radiant. Large, neutral flowers of certain shrubs
genera Viburnum, Hydrangea, and others.

Radiant Energy. Any wave motion in the ether
RADIATION.

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Radiant Heat. Misnomer for radiation of wave-
longer than that of visible radiation. See RADIATION.
Radiant Matter. Fourth form of matter, call
When the gaseous contents of a glass glob
fluidity.'
been rarefied to an extreme degree, the residue assum
Faraday 1816 "as far beyond vaporization as that is
culiar properties. That these properties may manifest
selves, the mean free path of the molecules must be a
as long as the largest dimension of the inclosing tube.
of particles in this condition is known as a Crookes' lay
the discharge of an induction coil be passed through th
the particles of radiant matter seem to shoot off in s
lines from the negative pole with very great velocity; c
coming in contact with solid matter, glass, for instan
liant phosphorescence is produced. The colors are vari
been opened. Radiant matter is also capable, when
characteristic, and thus a new field for the spectrosco
stream of molecules be directed upon the vanes of a si
volving wheel, it will arrest or produce great velocity
fied, of producing many interesting mechanical effects.
immediately. If the negative pole within the tube be
cave surface, so that the particles are directed to a fo
platinum strip, the latter may be heated nearly to the
point. Very elaborate and ingenious experiments hav
been made on this ultragaseous state of matter by W.
See CROOKES' TUBES.

Radiata. Animals possessing radial symmetry;
Icluded in the Coelenterates and Echinoderms.

Radiating Power. Property of emitting a gr
less quantity of radiant energy. Lampblack is on
best radiators known. The radiating and absorbing
of bodies are found to be equal in value, good radiato
Polished surfaces are poor radiato
good absorbers.
ABSORBING POWER, RADIATION and NON-CONDUCTORS.

Process of energy transference f
Radiation.
source to another by a wave motion. propagated by tr
vibrations in the so-called luminiferous ether. [T
wave-motion itself is sometimes called radiant energy
ation is set up in the ether by the vibration of the n
of ordinary matter. It may be due entirely to the n
the molecule as a whole, or partly to the vibration
parts of the molecules, this latter condition being s
that of a plate when vibrating in segments. All bodi
the absolute zero of temperature are radiators. The
wave length of the radiant energy sent out is an inve
tion of the absolute temperature of the body, though
longer than this minimum are present at the same
the temperature of the radiator is above ab.525° C., th
capable of affecting the eye and are called light. Of t
at the same temperature, that one is said to have th
radiating power which is capable of emitting the large
of radiant energy per unit of surface. The radiating
the sun is ab. 7.000 horse-power per sq. foot of his s
this ab. X10 part reaches the earth. and is equi
ab.83 foot-pounds per sq. foot of the earth's surface p
Radiant energy is sometimes divided into three parts
venience of reference; viz., radiant heat (sometimes
DARK HEAT [q.v.] rays), light, and the actinic ra
actinism or power of decomposition of any particu
rys depends entirely upon the nature of the compo
affected; hence it cannot be said that the actinic raf
one position in the scale of wave-lengths any more
other. The wave-length of radiant energy varies
very wide range. The length of waves radiated fro
of ice have been measured by Prof. Langley. From
limit we pass through the range of the visible rays
ab. 10 of a centimeter to ab. 5 of a centime
shortest waves which can be rendered visible only
The vibration frequency is said by Langley
tween the limits of ab. 107x1012 and ab. 40.000

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cence.

one point, and whi closed curve, suct & compelled by links? curve. The variati by varying the ap with the mean lice

ngth to the radius

Or "" measure of ass In degree measure. I 59+(=).

f certain shrubs of th ers.

otion in the ether. Se

adiation of wave-lengu See RADIATION.

n of matter, called zation as that is aber Es of a glass globe Lan the residue assumes ties may manifest then -lecules must be at leas inclosing tube. Abor nas a Crookes' laver. I passed through the tube to shoot off in strag y great velocity; ofte , glass, for instance, The colors are various ar for the spectroscope Le so capable, when elec mechanical effects. I n the vanes of a sma duce great velocity al within the tube be a cs are directed to a focus heated nearly to the fus -us experiments have te of matter by W. Cro

- radial symmetry; Dow
hinoderms.

Ey of emitting a greater
Lampblack is one d
ting and absorbing te
value, good radiators
es are poor radiators. >
NON-CONDUCTORS.

ergy transference from
on. propagated by trans
iniferous ether. T
called radiant energy.] 2
e vibration of the m
ue entirely to the nét
-tly to the vibrations
er condition being sina
segments. All bodies

- are radiators. The m y sent out is an invers of the body, though al present at the same t is above ab.525 C., the are called light. Oft One is said to have the e of emitting the larger

rface. The radiating p per sq. foot of his sate The earth, and is equ f the earth's surface per vided into three parts iant heat (sometimes ca

t, and the actinic ras

osition of any particul

e nature of the

id that the actinic ra ave-lengths any more -adiant energy varies of waves radiated from: Prof. Langley. From th nge of the visible rays,

b.

n of a centimete

rendered visible only or

is said by Langer

RADIATOR-RADIOPHONE

second, comprising by musical analogy ab. 8.5 octaves. Of
these light occupies hardly one octave, the limits of frequency
being ab. 392x1012 and 757x1012 per second.

Radiator. Closed vessel within which steam or hot water
circulates to keep it hot, and which heats objects by radiation

of its heat, and air by
contact for warming
buildings. The simplest
is a coil of wrought-iron
pipe, of " or 1" in diam-
eter, the rows of pipes
being joined at the ends
into return bends or into
a header or manifold or
special base casting at
one of the ends. The effi-
ciency of the pipe sur-
face has been increased
by adding an amount of
I coiled flat wire, fastened
to the outside of the pipe,
which increases the area
of the heating surface,
especially for air warm-
ing by contact. Cast-
iron radiators are best of
the pin-type, which also
air by contact. In direct radiators for apartments, ab. half a
acts most efficiently on
sq. ft. is allowed per sq. ft. of condensing area, or one sq. ft. of
heating surface per hundred cubic feet of volume; for indirect
radiation, where the radiators are in a cellar or out of the
room, and warmed air is to enter through flues, the allow-
ance is made one and a half times or twice that for direct
radiation.

Radical. In Chemistry, group of atoms which behave as a whole in any reaction, or one of the groups of atoms serving to make up a molecule. Thus C.H,, phenyl, is a radical in diphenyl, CH-CH-In Botany, organs approximate to the root, as radical leaves.

Radical Axis OF TWO CIRCLES. Straight line from any
point of which tangents to the circles will be equal. If the
circles intersect, it is their common chord indefinitely ex-
tended.

Radical Center. If three circles be taken in pairs,
the three radical axes will meet at a
called.
common point so

Radicals. Algebraic expressions subject to a sign indi-
cating that some root of the expression is to be taken. The
radical sign is . This sign is followed when necessary by a
vinculum covering the expression subject to the sign. The
radical sign without index denotes square root: in other cases
the root to be taken is shown by an index to the left and just
above the radical sign. Radicals of any degree may also be
indicated by fractional exponents having the index of the root
as denominator. The calculus of radicals is best discussed by
means of the fractional exponents modifying the fundamental
rules for combination to meet the fractional character of the
exponents.

Radicals. English Liberals of the extremer sort, aiming at thorough political reform, with a more or less clear and conscious tendency to democracy. They came into being ab. 1790. Similar parties or schools exist in every free or partially free country.

Radicant. Plants producing aerial or secondary roots.
Radication. Arrangement of roots of a plant either in
the soil or with relation to each other.

Radicellati. See CYCLOSTOMATA (Molluscoida).
Radicle. Rootlets of Mosses. See CAULICLE.
Radicolous. Plants parasitic on the roots of others.
Radiculose. Plants or parts of plants bearing numerous
rootlets; used especially in Bryology.

Radient of Meteoric Showers. Point in the heavens
from which the paths of the meteors appear to radiate during
a meteoric shower.

Radii of Radiates. See RADIAL SYMMETRY.

Radiograph. Invention of Olivier, designed to regulate the time of exposure of photographic plates by the mechanical action of the light rays. It consists essentially of a radiometer connected to a very light and delicately constructed speed indicator.

In strong cu

step by step at a proportionally more rapid rate, but wh eter will rotate more rapidly and cause the index to ad posed to a weaker light the pointer will require a 1 time to traverse the spaces between the graduations. the measure of the light action for any given time tained.

Radiolaria. Class of Rhizopods, including forms th semble the Heliozoa, but are marine, and have a centra sule and no contractile vesicle. They usually have a sili skeleton, which is either all outside the capsule (Ectolith partly within it (Entolithia). They may be solitary (Mon

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Radiolaria.

or colonial (Polycyttaria). The skeleton may consist of spicules
latticed concentric spheres. Yellow cells are often present
loosely joined, or of complicated radiating spokes, penetrating
See SILICOSKELETA and ACANTHOMETRIDE.

depending for its action upon the properties of a Crookes
Radiometer. Instrument devised by Dr. Crookes, and
layer. It consists of a small highly exhausted bulb of glass,
in the middle of which are fixed upon a freely rotating vertical
shaft four radial arms in the form of a rectangular cross.
the end of each arm is a little aluminium disk with its plane
At
vertical and blackened on one side. The black surface absorbs
radiant energy, while the bright side reflects it. The reaction
of each molecule then. when it comes in contact with the black
face of the vane, is more energetic than the impulse of a simi-
lar molecule on the cooler reverse side. When the instrument
is placed in the path of any radiation whatever, these unbal-
anced forces will tend to produce rotation of the flies, bright
side foremost.

the energy of an intermittent beam of light or radiant energy
Radiophone. Instrument constructed for converting
into that of sound. If such a beam be incident upon some sur-
face readily capable of rapid changes of temperature, the sur-
face will expand and contract: if these changes succeed one
another with sufficient rapidity, a sound will result. It has
been shown that the amplitude of the motion may exceed the
ten-millionth part of a centimeter. Graham Bell k..

out that sh

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