LITTLE BLUE BOOK NO. 452
Edited by E. Haldeman-Julius
A Dictionary of
Scientific Terms
Leo Markun
HALDEMAN-JULIUS PUBLICATIONS
GIRARD, KANSAS
Copyright, 1927
Haldeman-Julius Company
PRINTED IN THE UNITED STATES OF AMERICA
A DICTIONARY OF SCIENTIFIC TERMS
PREFACE
Completeness is a virtue which this little Blue Book cannot, in the
nature of things, possess. If any reader is disappointed not to find it
here, I must respectfully direct his attention to the three ponderous
tomes which make up a well-known dictionary of chemistry, to the still
larger and more numerous volumes devoted to a dictionary of applied
physics, and to other similar works. The sciences are many, and the
words which they employ exclusively or in senses peculiar to themselves
are exceedingly numerous.
Physics, chemistry, and biology contribute the greatest number of
words to the present dictionary. A few terms used in other sciences
are included, chiefly to show what I believe the proper scope of a
dictionary of scientific terms to be. There is a genuine need for a
large dictionary, which ought to be of about the same size as Webster’s
Collegiate or the Oxford Concise, and which should deal with the
vocabularies of economics, anthropology, sociology, and psychology as
well as with those of mechanics, geology, astronomy, and all the older
sciences. Such a dictionary should be written by specialists in the
various fields of knowledge with the aid of a skilled etymologist, and
under the supervision of an editor who is not himself a professional
scientist. It would be his special task to see that the definitions
are intelligible to non-specialists, and to literate laymen in
particular.
Of course no dictionary can take the place of primers of the sciences.
There are a number of excellent ones in this series, some of which I
referred to in writing this book. It is in many cases impossible to
give adequate explanations in a few words. Besides, the scientific
writers themselves frequently quarrel about the true meaning of such a
word as _ether_ or _instinct_.
I have dealt here with a number of words which are of significance when
we try to set the limits of science. _Common sense_, _philosophy_,
_theology_, and _superstition_ are examples. The claims of several
branches of knowledge to be considered sciences are also taken up.
A DICTIONARY OF SCIENTIFIC TERMS
_Abasia._ The inability to walk, especially when it is caused by mental
disorder.
_Abdomen._ The hind part of insects, spiders, etc. The belly, including
the nutritive organs.
_Aberrant._ Diverging from normal type.
_Aberration._ The non-convergence of rays of light to a focus. The
apparent displacement of the true position of a heavenly body.
_Abiogenesis._ Spontaneous generation.
_Abnormal._ Deviating from type.
_Aborigines._ The inhabitants of a region, or, in some cases, the
plants and animals, found by colonists. Literally, those that have been
in the land from the beginning of things.
_Abort._ Have premature delivery of a child. Remain undeveloped or
sterile, or dwindle away.
_Absolute._ Pure. The absolute, philosophically speaking, is final and
total reality.
_Absorption._ Disappearance through incorporation in something else.
The solution of a gas in a liquid is called absorption. Rays of light
may be absorbed in some mediums.
_Abstract._ Theoretical, aside from particular instances.
_Abulia._ Weakness of will.
_Abyssal._ Relating to the depths of the sea.
_Acaulescent._ Apparently stemless.
_Acceleration._ Rate of increase of velocity per time unit. Rate of
change of the velocity of a chemical reaction. The acceleration of a
star is the time it gains daily over the sun.
_Accident._ A property which is not essential to our conception of a
subject.
_Achene._ A small, dry, indehiscent, one-seeded fruit.
_Achromatic._ Colorless, transmitting light without decomposing it.
_Acid._ A substance that neutralizes and is neutralized by a base, and
which contains hydrogen. A compound that produces hydrogen ions when it
decomposes in aqueous solution.
_Actinium._ A radioactive substance, believed to be an element.
_Actinozoan._ One of a class of coelenterates including the corals.
_Aculeate._ Having a sting, prickly.
_Acuminate._ Tapering to a point.
_Adiabatic._ Maintaining a constant temperature.
_Adrenalin._ A crystalline substance obtained from suprarenal extract.
_Adsorption._ The condensation of dissolved substances on the surface
of a liquid or solid.
_Adventitious._ Not in the usual place, as a root.
_Aerial._ Atmospheric.
_Affect._ Disease, emotional complex.
_Afferent._ Conducting inward.
_Agoraphobia._ The morbid fear of public places.
_Agronomics._ The science of crop production. The scientific management
of land.
_Agrostology._ The study of the grasses.
_Air._ The atmosphere, a gaseous substance of which oxygen and nitrogen
are the principal constituents.
_Air pump._ A pump for forcing air into, or taking it out of, hollow
places.
_Albino._ An animal, especially a human being, characterized by the
congenital absence of coloring pigment in the skin, hair, and eyes. The
typical albino has very light skin and hair and pink eyes.
_Albumen._ A substance, usually edible, found between the skin embryo
of seeds.
_Albumin._ A class of proteids found in blood serum, milk, and muscle.
_Alcohol._ Ethyl alcohol, the substance which causes intoxication,
and a whole class of substances which are similar to it. They are
hydroxides of organic radicals.
_Alga._ Seaweed. Chiefly used in the plural: algae.
_Alkali._ Caustic hydroxides which form soluble soaps with fatty acids
and turn red litmus paper blue.
_Allotropy._ Variation of physical properties without change of
substance. Carbon, for example, may exist as lampblack, graphite, or
the diamond.
_Alloy._ A mixture (not a compound) of metals.
_Alluvium._ The deposit of earth and other materials by the mechanical
action of running water. More familiar is the adjective: alluvial.
_Alpha rays._ Becquerel rays which have less power of penetration than
beta rays but greater power of inducing conductivity in gases.
_Alpine._ Relating to a mountain district so high that it has arctic
climate.
_Alum._ A double sulphate of aluminium and potassium. Other sulphates
of similar crystalline form are also known as alums.
_Aluminium._ A metallic element. The spelling given is the usual one in
Great Britain, and it is also the one employed by American chemists. In
ordinary use in the United States: aluminum. The symbol: Al.
_Amalgam._ An alloy containing mercury. To amalgamate is to form an
amalgam.
_Ammeter._ An instrument for measuring the strength of electric
currents in amperes.
_Amorphous._ Uncrystallized.
_Ampere._ Sometimes spelled: ampère. The unit of electric current, the
current that one volt can send through one ohm.
_Amphibia._ A division of Vertebrata, intermediate between reptiles
and fishes, including the frog. The study of Amphibia is known as
amphibiology.
_Amplexicaul._ Encircling or clasping a stem.
_Anabolism._ Constructive metabolism.
_Analogy._ Functional correspondence between parts of different origin
and structure.
_Analysis._ Resolution into simple elements, as by chemical processes.
In mathematics, algebraic investigation.
_Anandrous._ Without stamens.
_Anaphylaxis._ Excessive susceptibility to an albuminous substance.
_Anatomy._ The science of bodily structure.
_Anemograph._ An instrument for recording the direction and force of
wind.
_Aneroid barometer._ A barometer in which there is no liquid, the
pressure of the air being measured by its action on the elastic lid of
a box in which a partial vacuum has been created.
_Angiosperm._ A plant of a class which has its seeds in a closed ovary.
_Anhydrous._ Without water of crystallization or water in general.
_Animal._ A living being distinguished from plants in that it is
capable of voluntary motion and sensation. Some recent investigations
appear to lead to the conclusion that other differentia will have to be
adopted. The human being, incidentally, is an animal, although popular
language sometimes distinguishes man from the animals.
_Animalcule._ A minute animal, usually one which cannot be seen with
the naked eye.
_Anion._ A negative ion.
_Annual._ A plant that lives only for a year.
_Annulate_, _annulated_. Ringed.
_Anode._ A positive electrode.
_Antenna._ Feeler, sensory organ found in pairs on heads of insects and
crustacea. Irritable processes found in some male flowers. An elevated
conductor for receiving or transmitting electric waves. Plural: antennæ.
_Anther._ The part of the stamen which contains the pollen.
_Anthropogeography._ The science which treats of geography as applied
to man. That part of anthropology dealing with the effect of the
environment on human beings. There are a number of compounds beginning
with anthro-. The meaning may often be understood by remembering that
the Greek word _anthropos_ means man, not as opposed to woman but as
excluding the non-human.
_Anthropology._ The study of man as an animal, with respect to race,
distribution, culture, and social organization.
_Anticlinal._ Forming a ridge with strata leaning in opposite
directions from an axis. Having an upright spine toward which spines on
both sides lean.
_Anticyclone._ An outward and rotary flow of air from an atmospheric
area of high pressure.
_Antidote._ A medicine used to counteract a poison or disease.
_Antimony._ An element of metallic appearance. Symbol: Sb.
_Anus._ The posterior opening of the alimentary canal.
_Apetalous._ Without petals.
_Aphasia._ Loss of speech from a brain injury.
_Aphelion._ The point in the orbit of a planet or comet farthest from
the sun.
_Apheliotropic._ Turning away from the sun.
_Apogee._ The point in the orbit of a planet or the moon where it is
farthest from the earth.
_Aponeurosis._ The flat, dense connective tissue covering and forming
the attachments of certain muscles.
_Aquatic._ Growing or living in or near the water.
_Arachnida._ A class of animals including spiders and scorpions.
_Arachnoid._ Covered with long, thin hairs. A serous membrane
enveloping the brain and spinal cord.
_Arboreal._ Living in or connected with trees.
_Archeology._ The study of prehistoric antiquity, or sometimes of
antiquity which is not prehistoric.
_Archean._ Also: Archaean. Relating to the earliest geological period.
_Arenicolous._ Living in the sand.
_Argon._ A gaseous element found in the atmosphere in small amounts.
Symbol: A.
_Arsenic._ A semi-metallic element. Symbol: As.
_Art._ Skill of various sorts. Knowledge from the practical point of
view. H. W. Fowler distinguishes it from science: “Science knows,
art does; a science is a body of connected facts, an art is a set
of directions; the facts of science (errors not being such) are the
same for all people, circumstances, and occasions; the directions
of art vary with the artist and the task.” According to the Oxford
English Dictionary: “The distinction as commonly apprehended is that a
science is concerned with theoretic truth, and an art with methods for
effecting certain results. Sometimes, however, the term _science_ is
extended to denote a department of practical work which depends on the
knowledge and conscious application of principles; an art, on the other
hand, being understood to require merely knowledge of traditional rules
and skill acquired by habit.”
_Articulation._ A joint, as between bones or parts of plants,
especially between parts which may separate at any time.
_Ascendant._ Rising toward the zenith.
_Asexual._ Without sex.
_Assay._ A sort of analysis, especially of metals.
_Association._ Mental connection. The word has also three or four
meanings in chemistry, which cannot be explained briefly.
_Asteroid._ A minor planet.
_Astronomy._ The science of the heavenly bodies.
_Astrophysics._ The science which deals with the constitution of the
heavenly bodies. It is a branch of astronomy.
_Atmosphere._ The gaseous envelope about a heavenly body. Especially
the air which surrounds the earth. As a measurement, a pressure of
fifteen pounds per square inch.
_Atom._ The smallest particle of an element that enters into
combination. According to old definitions, it is indivisible.
_Aurora._ A luminous atmospheric phenomenon. The aurora borealis
radiates from the north magnetic pole, the aurora australis from the
south magnetic pole of the earth.
_Avogadro’s Hypothesis._ The assumption that equal volumes of gases
contain equal numbers of molecules if conditions of temperature and
pressure are the same. It appears to be close to the truth.
_Axiom._ A truth which is considered self-evident.
_Bacillus._ One of a sort of rod-shaped bacteria. Loosely, any
bacterium. Plural: bacilli. The Oxford English Dictionary distinguishes
bacillus from bacterium, “with which it agrees in its rodlike form, and
characterized by its larger size and mode of reproduction.”
_Bacterium._ More familiar in plural: bacteria. A group of vegetable
microörganisms. Not all cause disease.
_Barbarian._ Of a civilization intermediate between one which is called
savage and the most complex forms.
_Barium._ A silver-white element, classed as a metal. Symbol: Ba.
_Barometer._ An instrument used to measure atmospheric pressure, and
thus to predict storms or determine altitudes.
_Base._ A substance which can neutralize acids to form a salt. The term
includes alkalis. Part of an organ (of a plant or animal) attached to
another organ which is more central.
_Batrachia._ An order of amphibians which have no tails in the adult
stage.
_Battery._ A system of cells (sometimes used for a single cell) which
changes chemical energy into electricity.
_Becquerel rays._ Rays emitted by radium and other substances which are
susceptible to deflection by electricity and which electrically charge
other bodies.
_Behaviorism._ Watson’s psychological system. Opposed to introspective
psychology, and it emphasizes the physiology of human behavior.
_Bessemer steel._ Steel made from cast iron by a process which burns
out carbon, sulphur, and phosphorus.
_Beta rays._ Becquerel rays which are apparently identical with cathode
rays.
_Bichloride._ A compound in which there are two atoms of chlorine in
the molecule.
_Biennial._ A plant that rises one year and flowers, fructifies, and
dies the next.
_Binary._ Composed of two elements.
_Biochemistry._ The chemical study of living organisms and their
products.
_Biology._ The science of living organisms.
_Biophore._ The indivisible unit of life. The biophore cannot support
life if split up.
_Bird._ One of a class of feathered and warm-blooded vertebrate animals.
_Bisexual._ Pertaining to, or containing the organs of, both sexes.
_Bismuth._ A metallic element. Symbol: Bi.
_Boron._ A non-metallic solid element. Symbol: B.
_Botany._ The science of plants.
_Boyle’s Law._ The theory that the pressure exerted by air is directly
proportional to its density. This is now believed to be true only
approximately.
_Brachycephalic._ Pertaining to skulls of which the breadth is at least
four-fifths of the length. Short-headed.
_Brass._ An alloy of copper and zinc.
_British Thermal Unit._ The amount of heat which is capable of raising
the temperature of one pound of water by one degree Fahrenheit. The
usual abbreviation: B.T.U.
_Bromine._ A liquid element. Symbol: Br.
_Bronze._ An alloy of copper and tin, usually with small amounts of
zinc.
_Brownian movement._ A movement of minute drops of oil suspended in
stagnant air, apparently due to molecular motion.
_Bunsen burner._ A sort of burner much used by chemists, within which
air and fuel gas are mixed.
_Burn._ To oxidize in such a way that heat and light are produced.
_Cadmium._ A metallic element. Symbol: Cd.
_Caesium._ A metallic element. Symbol: Cs. It somewhat resembles
potassium.
_Calcium._ A metallic element. Symbol: Ca. Compounds of calcium are
common, but the element is not to be found in a pure state.
_Calculus._ Solid concretion in the body. A branch of mathematics,
differential and integral calculus, which deals with problems of
constant variation or motion, and which has been of great importance in
modern science.
_Calorie._ The unit of heat, the amount of heat necessary to raise the
temperature of a gram of water one degree Centigrade. This is the small
calorie. Confusion sometimes results because the large calorie, which
is one thousand times the small one, is called simply the calorie,
without any qualification, in discussions about food. It is sometimes
known as the great calorie. The small calorie is best called the
gram-calorie.
_Calorimeter._ An instrument for measuring quantities (not degrees) of
heat.
_Calyx._ The outer case of a bud.
_Cambrian._ Relating to the lowest of the Paleozoic rocks and the
earliest part of the Paleozoic period.
_Candlepower._ The unit of illumination, measured by a standard candle.
The illumination produced one foot away from a standard candle is the
candle foot.
_Capillarity_ or _capillary attraction_. A phenomenon best illustrated
in very slender (capillary) tubes, in which the liquid rises, or, if it
does not wet the tube, sinks. In the latter case we speak of capillary
repulsion.
_Capital._ In economics, wealth employed for the purpose of production.
_Carbolic acid._ Phenol, not a true acid.
_Carbon._ An element which exists in three allotropic forms. Symbol: C.
The oxides are important, and there are many organic compounds.
_Carboniferous._ Pertaining to a Paleozoic (geological) period
following the Devonian.
_Carburetor_ or _carburettor_. A device which mixes air with petroleum
vapor, or one which puts illuminants into water gas.
_Cardio--._ Heart--, in many combinations.
_Carina._ A ridge-shaped structure.
_Carnivora._ The flesh-eating mammals.
_Carpel._ An organ which is part of the pistil.
_Catabolism._ Destructive metabolism.
_Catalysis._ The effect produced by a substance (called the catalyst,
the catalytic agent, or the catalyzer) which aids a chemical change in
other bodies, undergoing no change of its own.
_Cathode rays._ Rays discharged from the cathode (negative pole) of a
vacuum tube. They are considered streams of electrons, which may be
projected at a velocity of 100,000 miles per second.
_Caudal._ Relating to the tail.
_Cause._ That which brings about something else (an effect). Professor
Adam Leroy Jones says: “It has been objected that we can never observe
one thing producing another; that we can at most observe that one thing
is followed by another, and perhaps find reason for believing that it
will always have such connection; and that to say that A _produces_ B,
is to raise a metaphysical question with which science and everyday
thinking are not concerned.... Is it sufficient to say that cause
means simply invariable connection? No, for the succession of day and
night is an invariable succession. The notion of cause implies that
the relation of cause and effect not only _is_ invariable, but also
that it must _be_ so; that there is an _unconditional_ or necessary
connection between the two; that if the first does not happen, the
second cannot.... A causal law is a statement, in general terms, of a
causal connection.”
_Cell._ A battery unit, a device for changing chemical energy into
electricity. The structural unit of which living beings are composed.
An enclosed cavity in an organism or a mineral. A covering which
protects the eggs or the young of certain animals.
_Celsius._ Centigrade (thermometer).
_Cenogetic._ Pertaining to individual development which does not repeat
the development of the group of which the individual is a member.
_Cenozoic._ Relating to the geological age of the mammals. It is still
in existence.
_Center of gravity._ The point in a body where its entire weight may be
assumed to be concentrated.
_Centigrade._ A thermometer, or the scale on which it is based, with
the boiling point of water at 100 and the freezing point at zero, under
standard conditions of pressure. Abbreviation: C. Such a scale is far
more useful to scientists than that of Fahrenheit.
_Centimeter._ One hundredth of a meter.
_Centrifugal._ Flying or tending to fly away from the center.
_Centripetal._ Tending to move toward the center.
_Centrosome._ A minute body found in the cytoplasm or the nucleus of
some (biological) cells.
_Centrum._ The center of an earthquake.
_Cephalic._ Relating to the head.
_Cephalopoda._ The highest class of mollusks.
_Cereal._ A grass which produces edible grain.
_Cerium._ A metallic element. Symbol: Ce.
_Cetacea._ The order of mammals including the whales.
_Chemistry._ The science which deals with the composition of matter and
its transformations.
_Chiroptera._ An order containing the bats.
_Chloride._ A chlorine compound.
_Chlorine._ A gaseous element. Symbol: Cl.
_Chlorophyll._ The coloring-matter of green parts of plants.
_Chromatic aberration._ The colored fringe seen at the edges of images
formed by a simple lens, because of the difference in wave lengths of
the various rays.
_Chromium._ A metallic element. Symbol: Cr.
_Chromo-._ Color-, in many compounds. Also: chroma-, chromato-.
_Chromosome._ One of the small bodies formed out of a protoplasmic
substance (chromatin) in the nucleus before a cell divides.
_Civilization._ An advanced stage of culture. Civilization is sometimes
contrasted with culture, but the matter is one which cannot be
considered here.
_Class._ A group of animals or plants, more comprehensive than an order
and less so than a phylum.
_Climate._ The average weather conditions of a particular place or
region.
_Cobalt._ A metallic element. Symbol: Co.
_Coccus._ A spherical bacterium. A sort of carpel.
_Coelenterata._ A phylum of invertebrate animals including the corals.
_Cohesion._ Molecular attraction within a body.
_Colloid._ Not crystalloid. A substance which does not form a true
solution. Colloidal liquids have very little osmotic pressure.
_Columbium_ or _niobium_. A metallic element. Symbol: Cb.
_Combustion._ Oxidation accompanied by the production of heat and
light. Less frequently, the word is used for a combination which is not
oxidation or where no heat or light is produced.
_Common sense._ Ordinary and non-scientific thought processes.
Scientific thinking is more exact and more fertile.
_Community._ A social group.
_Comparative._ Involving comparison, as between man and the other
animals.
_Complex._ In psycho-analysis, a cluster of ideas and mental images
joined together by a stressed emotion; especially such a cluster that
is thrust out of consciousness (repressed).
_Component of a force._ The effective value of a force in a given
direction.
_Compound._ A substance consisting of two or more chemical elements in
combination.
_Compound animal, flower, leaf, etc._ An animal, etc., consisting of a
combination of organisms or simple parts.
_Conation._ Will, directing power, effort.
_Concave._ Curved like the interior of a circle or sphere.
_Concept_ or _conception_. The idea, notion, or thought held about
anything. Conception includes symbol and meaning.
_Condense._ Change from gas to liquid. Concentrate (electricity). Of
organic compounds, react in a certain way so as to form new bonds.
_Conduct._ Carry heat or electricity.
_Conductance._ Ability to conduct. The word is used to describe the
property of a conductor.
_Conductivity._ Power to conduct (heat or electricity).
_Conductor._ That which readily conducts (heat or electricity).
_Congeal._ Solidify, freeze.
_Connate._ United from the beginning.
_Constant._ A quantity that does not vary, or one that does not change
under given conditions.
_Convex._ Curved like the outside of a circle or sphere.
_Coördinate._ Each of a system of magnitudes used to fix the position
of a point, line, or plane.
_Copernican._ Relating to the theory that the planets (one of which is
the earth) move around the sun.
_Copper._ An important metallic element. Symbol: Cu.
_Corolla._ The inner envelope of a flower.
_Corona._ A small disk of light around the sun or moon. An appendage on
top of a seed or the inner part of the corolla.
_Cotyledon._ One of the first leaves in the embryo of a higher flower.
_Coulomb._ The amount of electricity carried in one second by one
ampere.
_Cretaceous._ Of or like chalk. Relating to the last Mesozoic period.
_Cri._ The common respiratory infections, such as the common cold,
influenza, etc.
_Criminology._ The scientific study of crime and criminals.
_Cross-pollination._ The transfer of pollen from the anthers of one
flower to the stigma of another flower of the same kind.
_Crustacea._ A class of hard-shelled arthropods, including lobsters and
crabs.
_Crystal._ An aggregation of molecules with definite internal structure
and external form of a solid enclosed by symmetrically arranged plane
faces. A crystal is formed when certain liquids or gases solidify
(crystallize). The study of crystal structure is crystallography.
_Ctenophora._ A class of low animals comprising certain jellyfish.
_Cycle._ A series of operations in a heat engine. A two-cycle engine
is one with a cycle of two strokes. Properly, it should be called a
two-stroke-cycle engine.
_Cyclone._ A violent wind of low diameter. A circular wind system about
an area of low pressure.
_Cyst._ A hollow organ containing a liquid secretion.
_Cyto-._ Cell-, in compounds.
_Cytoplasm._ Cell protoplasm, not including the nucleus.
_Darwinism._ Organic evolution in general. The theory that the origin
of species is due to natural selection, as developed by Charles Robert
Darwin. All biologists worthy of the name believe in evolution, but by
no means all accept Darwinism in the narrow sense.
_Declination._ The angular distance of a heavenly body north or south
of the celestial equator. The deviation of a magnetic needle from true
north.
_Decurrent._ Extending downward, as the base of a leaf.
_Dehydrate._ Remove water, dry.
_Dendrology._ The scientific study of trees.
_Devonian._ Of the geological formation between the Silurian and the
Carboniferous.
_Dew point._ The temperature at which the air is saturated with
water-vapor.
_Diadelphous._ Formed into two bundles. (Of stamens.)
_Diandrous._ With two stamens.
_Dielectric._ Insulating, insulator of electricity.
_Diesel engine._ An internal combustion motor which compresses the air
highly and which successfully burns oil which is unsuitable for the
ordinary motor of an automobile.
_Disease._ Malady. Of some foods and drinks, an impairment in quality
caused by bacteria.
_Dissipation of energy._ The change of energy to such a form that it
cannot be used to do work.
_Dissociate._ Ionize, decompose, split up.
_Doldrums._ A region of calms and light winds near the equator.
_Dolichocephalic._ Long-headed, having a skull with the breadth less
than four-fifths of the length.
_Drug._ A medicine, a medicinal agent, especially one of vegetable
origin.
_Dynamics._ The branch of physics dealing with forces.
_Dyne._ The amount of force that acts for a single second on a mass of
one gram to give it a velocity of one centimeter per second.
_Eccentric._ Not concentric to a given circle. Arranged to change
rotary motion back and forth.
_Echinoderm._ One of a class of animals including the sea-urchins.
_Eclipse._ Of a heavenly body, obscured by passing between it and the
observer or its source of light.
_Ecliptic._ The apparent orbit of the sun.
_Ecology._ The science dealing with the relations between organisms and
their environment.
_Economics._ The science of wealth, especially of its production,
distribution, and consumption.
_Edentate._ Toothless or without canine teeth.
_Effect._ See Cause.
_Efferent._ Carrying outward or away.
_Efficiency._ The ratio between the amount of work put into a machine
and the amount derived from it.
_Efflorescence._ The loss of water of crystallization.
_Electricity._ A peculiar condition of the molecules of a body or of
the ether surrounding the molecules, or else a sort of fluid or other
matter in the form of small bodies called electrons. It is easier to
tell what electricity does or how it is produced than to define it,
especially since physicists have not been able to agree about its
precise nature.
_Electrode._ Either pole of a cell.
_Electrolysis._ The decomposition of a compound by means of an electric
current.
_Electrolyte._ A substance which, in solution, can carry an electric
current to an appreciable extent.
_Electron._ The electric charge of an atom. A very small particle which
is electrically charged. The size of the electron has been variously
calculated, and some physicists declare that the negative electron has
only 1/1700 the mass of a hydrogen atom.
_Element._ One of a number of substances formerly considered to be
indivisible. An electric cell.
_Emanation._ A gaseous substance produced by a radioactive material.
_Embryo._ The offspring of an animal before birth or emergence from the
egg. The scientific study of the embryo is called embryology.
_Endogenous._ Growing from within.
_Endosperm._ The nutritive tissue enclosed with the embryo in seeds.
_Endothelium._ The layer of cells lining blood vessels, the interior of
the heart, etc.
_Energy._ Ability to do work or change the nature of bodies. Heat and
light are considered forms of energy.
_Entomology._ The study of insects.
_Environment._ Surrounding conditions, influences, and powers of all
sorts. Everything which, directly or indirectly, affects the fate of an
organism forms part of its environment.
_Eocene._ Relating to the lowest division of the Tertiary strata.
_Epiphyte._ A plant which grows upon another but which is not fed by
it. A vegetable parasite on an animal body.
_Equation._ A compensation for inaccuracy. In mathematics, a formula
affirming the equivalence of two expressions. An expression in symbols
of a chemical reaction.
_Equinox._ The time when the sun crosses the equator, and day and night
are of equal length.
_Erbium._ A metallic element. Symbol: Er.
_Erg._ The work done by a force that, when it acts for one second on
mass of one gram, produces a velocity of one centimeter per second.
_Erosion._ Gradual destruction or wearing away, as of land by water.
_Esthetics._ Also spelled: æsthetics. The study of beauty. It is, at
present, rather an art or a branch of philosophy than an exact science.
_Ether._ An anesthetic liquid. Totally distinct is this meaning: the
medium through which light-waves pass, which is supposed to have a
density infinitely less than that of the lightest gas. The nature of
the ether is in dispute.
_Ethics._ The branch of philosophy concerned with human conduct. It may
at some future time rank as a science.
_Ethnology._ The science dealing with the races of mankind. It has not,
alas, always been thoroughly scientific.
_Ethyl alcohol._ The alcohol which cheers and also inebriates men.
Before Prohibition, practically the only kind of alcohol which people
drank.
_Europium._ A metallic element. Symbol: Eu.
_Evaporate._ Change (usually with no great rapidity) from the liquid to
the gaseous state.
_Evergreen._ A tree or shrub which has green leaves in all seasons.
_Evolution._ Development, change. In biology, the development of a race
or species by gradual change from another type. The Theory of Evolution
contradicts the notion that every type was originally created in the
form which it now has.
_Experiment._ An event (or, in the case of the verb: to bring about
an event) designed for observation, in order that an unknown fact or
principle may be brought to light, or simply to instruct.
_Explain._ To reduce a phenomenon to the terms of a general principle.
To bring into a system.
_Fact._ Something which is true. If only a single investigator has
reported a certain circumstance or condition, it is not likely to be
considered a fact by scientists.
_Factor._ A substance which takes part in a chemical reaction.
_Facula._ A bright spot or streak on the sun.
_Fahrenheit._ A thermometric scale, in common household use, but
employed for scientific purposes far less frequently than the
Centigrade scale. The boiling point of water is 212 degrees and the
freezing point is 32 degrees above zero.
_Fair._ As used by the American Weather Bureau, without rain, snow, or
hail.
_Feces._ Excrement.
_Fecundate._ Impregnate, fertilize, make fruitful.
_Female._ Bearing fruit or offspring, pistillate.
_Ferment._ To cause an organic substance to change or to work (used of
organic substances), because of the activity of yeast, or of certain
other living organisms or substances derived from them.
_Filament._ The part of the stamen that supports the anther. The
conductor in an incandescent electric light.
_Fish._ A member of a class of vertebrate and cold-blooded animals
having gills and usually fins and scales.
_Flocculus._ A mass in the atmosphere of the sun resembling wool or
clouds.
_Florescence._ The time or condition of flowering.
_Flower._ The reproductive organ in a plant which contains one or more
pistils or stamens or both, and typically a corolla and calyx. To
flower: to blossom or produce flowers.
_Fluid._ Moving readily. The fluids include the liquids, the gases,
perhaps the ether of space.
_Fluorescence._ The colored light produced in some transparent bodies
by the action of ultra-violet rays. The property some substances have
of emitting light when exposed to certain rays.
_Fluorine._ A gaseous element. Symbol: F.
_Focus._ The point at which rays meet after reflection or refraction.
Converging-point.
_Force._ That which changes or tends to change the motion of a body
upon which it acts.
_Foreconscious._ Mental processes of which we are aware only under
special conditions. Of a nature between conscious and unconscious.
_Forensic._ Used in law-courts.
_Formula._ A symbolic statement, as in mathematics or chemistry.
_Fossil._ Something left of an animal or a plant which lived in a
former geological age.
_Freeze._ To change from a liquid to a solid, especially by removing
heat.
_Friction._ The resistance which one body encounters in rubbing against
another.
_Fruit._ A ripened ovary together with any parts of the flower that may
be attached to it.
_Fulcrum._ The point where a lever is supported or turns.
_Function._ A quantity related to another in such a way that a change
in one involves a change in the other.
_Functional._ Having a use. Of a disease, not affecting the structure
of an organ, or of the organ which is supposed to be diseased. It is
doubtful if there can be a disease which does not change the structure
of some organ.
_Fundamental notes._ The notes resulting when a piano wire vibrates as
a whole. The lowest notes of chords.
_Fungus._ Plural: fungi. A cryptogamous (flowerless) plant without
chlorophyll. A morbid growth.
_Fuse._ To change, usually by adding heat, from solid to liquid form.
_Gadolinium._ A metallic element. Symbol: Gd.
_Gallium._ A metallic element. Symbol: Ga.
_Gamete._ A sexual cell which unites with another for reproduction.
_Gamma rays._ Becquerel rays which are more penetrating than beta rays
and are not deflected by electricity. Equivalent or analogous to X-rays.
_Ganglion._ An enlargement of the nerve from which nerve-fibers radiate.
_Gas._ A fluid which tends to occupy the whole volume of any vessel in
which it is placed.
_Gastropoda._ A class of mollusks including the snails.
_Geld._ Castrate.
_Generalization._ A universal assertion, a principle applying not to
any single fact but rather to a large number. A general notion.
_Genetics._ The study of heredity and of the beginning of variation.
_Genital._ Pertaining to reproduction and the sexual organs.
_Genus._ In logic, a class which is divided into sub-classes. In
biology, a class of animals usually containing several species. A
single genus may in some cases make up a genus of its own, if it
appears not to be closely related to any other genus. Plural: genera.
The next higher group is the family.
_Geo-._ In combinations, earth——.
_Geography._ The study of the earth, especially as the environment of
man.
_Geology._ The study of the crust of the earth.
_Germ._ A portion of an organism capable of becoming a new one. Seed,
microörganism. Popularly, a germ is a bacterium which causes disease.
_Germanium._ A metallic element. Symbol: Ge.
_Glacier._ A slowly-moving mass of ice formed by the accumulation of
snow on high ground.
_Gland._ An organ which secretes constituents of the blood. Secreting
cell or cells in plants.
_Glans._ The body at the end of the penis and clitoris.
_Glass._ A substance made by mixing silicates and including some alkali
silicate. Not every sort of glass is transparent.
_Glomerate._ Gathered in a compact group.
_Glottis._ The opening at the upper end of the windpipe.
_Glucinum_ or _beryllium_. A metallic element. Symbol: Gl or Be.
_Glucose._ One of a group of sugars, including grape sugar.
_Gneiss._ A sort of highly crystalline rock arranged in layers, as of
quartz and mica.
_Gold._ A metallic element. Symbol: Au.
_Gram._ The unit of weight in the metric system. About the weight of a
cubic centimeter of water at its greatest density.
_Graph._ A symbolical diagram, as in mathematics of chemistry.
_Gravity_ or _gravitation_. The attraction existing between bodies. If
the earth draws a falling apple, it is said that the apple also draws
the earth to it.
_Gregarious._ Living in or pertaining to flocks, groups, or
communities. Social.
_Gymnosperm._ A plant whose seeds are not enclosed in seed-vessels.
_Habit._ An action pattern; specifically, one that has been acquired.
In biology, a mode of growth.
_Hallucination._ The perception of something which is not actually
present.
_Hardness._ The presence of certain salts in water.
_Heat._ Energy which can be transmitted by conduction or radiation, and
which is expressed in molecular motion.
_Helium._ A gaseous element. Symbol: He.
_Henry._ The unit of inductance. The inductance in a circuit in which
the induced electromotive force is one volt when the inducing current
varies at the rate of one ampere per second.
_Herb._ A plant whose stem is not woody or persistent.
_Hermaphrodite._ An organism possessing male and female characteristics
or organs.
_Herpetology._ The study of reptiles.
_Hexapoda._ The order of insects.
_Hilum._ The point where the seed is attached to the seed-vessel.
_Hinterland._ The district behind a coast.
_Histology._ The study of organic tissues, usually with the aid of a
microscope.
_History._ The study of the past. It deals with human institutions
rather than with the animal, vegetable, or mineral kingdom. History is
concerned first of all with concrete data, specific cases, and then
with explaining them in the light of general laws. There have been some
ingenious, but not altogether successful, attempts to make history into
a science.
_Holmium._ A metallic element. Symbol: Ho.
_Homo-._ In compounds: same, similar.
_Homology._ That relation between parts which results from their
development from corresponding embryonic parts, either in different
animals or in the same individual.
_Hormone._ A stimulating substance carried from one organ to another.
_Horse-power._ The unit of power in the English system. It is equal to
550 foot pounds per second.
_Humidity._ Moisture.
_Hurricane._ A wind of stormy violence.
_Hybrid._ The offspring of two plants or animals of different sorts.
_Hydrate._ A compound containing combined water.
_Hydraulics._ The science dealing with liquids in motion.
_Hydrocarbon._ A compound of carbon and hydrogen.
_Hydrogen._ A gaseous element. Symbol: H.
_Hydrolysis._ The decomposition of water in such a reaction as includes
the formation of new compounds with the hydrogen and the oxygen of the
water.
_Hydrometer._ An instrument used to determine the specific gravity of a
liquid.
_Hydrostatics._ The science which deals with the pressure of liquids.
_Hydrous._ Containing water, whether in combination or in a mixture.
_Hydrozoan._ A member of a class (Hydrozoa) of coelenterate animals,
chiefly marine, including jellyfish.
_Hygiene._ The science of sanitation, preventive medicine. In the
United States, textbooks of hygiene are chiefly concerned with proving
that alcohol and tobacco are injurious. Here is an example of “science”
created by legislative fiat.
_Hygrometry._ The measuring of atmospheric moisture.
_Hypothesis._ A supposition used as a basis for reasoning, a
provisional explanation. If it appears to be unconfirmed by the facts,
it is rejected. Otherwise it becomes a theory, then a law.
_Igneous._ Formed by great heat, as rocks.
_Indehiscent._ Not bursting open at maturity.
_Indium._ A metallic element. Symbol: In.
_Indo-European_ or _Indo-Germanic_. Pertaining to a great family of
languages including most of those spoken in Europe and by the white men
in America as well as some used in India and other parts of Asia.
_Inductance._ The electrification of a conductor placed near a circuit
or charged body, resulting from the proximity.
_Inert._ Not easily made to react.
_Inertia._ The property of matter by which it tends to remain at
rest if it is at rest, or, if it is in motion, to remain in motion
in a straight line. Our notion of inertia may possibly be changed by
Einstein’s theory.
_Inflorescence._ Flowering, the arrangement of flowers on a plant.
_Infra-._ In compounds, below.
_Infusoria._ A class of protozoa which possess hairlike outgrowths.
_Inorganic._ Not derived from living organisms. Pertaining to the
chemical compounds which do not contain carbon--but carbonates and a
few other carbon compounds are considered to be inorganic.
_Insect._ A member of a class of small and invertebrate animals, all of
which have bodies clearly divisible into head, thorax, and abdomen.
_Instinct._ An action pattern present from birth. (The varying theories
of instinct, especially with regard to man, are often based upon
varying definitions. This is true of many of the terms here defined.)
_Intelligence quotient._ The ratio between the “mental age” of an
individual and the true age. The true age is often easier to determine
than the mental age, that is, the age which a normal individual of
a given intelligence possesses. How can intelligence be expressed
numerically? Abbreviation: I. Q.
_Interference._ The influence which two waves have upon each other.
_Invertebrate._ Spineless, having no backbone.
_Iodine._ A solid, non-metallic element. Symbol: I.
_Ion._ Either of the substances that appear at the poles in
electrolysis. Particle which carries electric charge. Positive ions are
cations, negative ions are anions.
_Iridium._ A metallic element. Symbol: Ir.
_Iron._ An important metallic element. Symbol: Fe.
_Isobar._ A line connecting places which have the same barometric
pressure (with corrections for varying altitude) at a given time or
over a given period.
_Isotherm._ A line connecting places which have the same temperature at
a given moment or over a stated period of time.
_Joule._ A unit of work. It is equal to ten million ergs, and it is
about the energy expended in one second by an electric current of one
ampere in a resistance of one ohm.
_Jurassic._ Of that Mesozoic period following the Triassic.
_Kidney._ One of a pair of organs which secrete urine.
_Kilogram._ A unit of mass in the metric system, about the mass of a
cubic centimeter of water at its greatest density.
_Kinetic theory of gases._ The assumption and the teaching that
the molecules of gases are constantly in motion and that the space
between molecules is far greater than that occupied by the molecules
themselves. The velocity of gas molecules is supposed to be very great.
_Krypton._ A gaseous element. Symbol: Kr.
_Labile._ Unstable.
_Lanthanum._ A metallic element. Symbol: La.
_Latent heat._ The equivalent of the work performed in changing the
state of a substance from solid to liquid or liquid to gaseous.
_Law._ A generalization. A statement of the way things invariably
behave under given conditions. A scientific law does not direct or
impose penalties or state that things ought to behave in a certain way.
It is a correct statement of invariable sequence. If the correctness of
a statement has not been proved beyond a reasonable doubt, it is not a
law.
_Lead._ A metallic element. Symbol: Pb.
_Leaf._ One of the expanded organs, usually green, springing from the
stem, a branch, or sometimes a root, of a plant.
_Lens._ A portion of glass or other transparent substance with one or
both sides curved, used to alter the direction of light rays.
_Leucocyte._ A colorless corpuscle of the blood.
_Lever._ A rigid structure used to modify force and motion while
transmitting it.
_Life._ The quality which differentiates the organic from the
inorganic. The ability to reproduce itself seems to be the
differentiating characteristic of a living organism.
_Light._ A form of energy which is apprehended by the eye. It is
supposed to move at a velocity of about 186,300 miles per second.
_Limb._ In astronomy, an edge or border. This is not the same word
etymologically as the one which means an arm, a leg, or a wing.
_Lithium._ A metallic element. Symbol: Li.
_Litmus._ A substance which is turned red by acids and made blue again
by bases. Paper stained with litmus is usually employed for such tests.
_Logic._ The science of thought. Scientific method.
_Lutecium._ A metallic element. Symbol: Lu.
_Magnesium._ A metallic element. Symbol: Mg.
_Magnetize._ To change into a magnet, give magnetic quality to, make
capable of attracting iron.
_Male._ Of the sex or the organs that fecundate. Of a reproductive
organ that fertilizes.
_Mammal._ One of the class of animals (Mammalia) which are vertebrate
and which are distinguished by suckling their young.
_Mandible._ Jaw, especially the lower jaw. Part of a beak.
_Manganese._ A metallic element. Symbol: Mn.
_Marsupial._ One of an order of animals (Marsupialia) which are low
mammals, and most of whose females carry the young in abdominal pouches.
_Mass._ Quantity of matter. This remains constant, but weight varies a
little with geographical location.
_Materia medica._ The study of medicinal substances.
_Mathematics._ The science of space and quantity as such.
_Matter._ That which takes up space.
_Mean._ Equally removed from two extremes, average.
_Mechanics._ The science of motion. The study of the action of force on
bodies. May be considered a branch of mathematics or of physics.
_Medicine._ The art of maintaining and restoring health. Surgery is
sometimes excluded from the conception of medicine. The basis of
medicine is only partially scientific.
_Megacephalic._ Large-headed.
_Melt._ To change from the solid to the liquid form.
_Mendel’s Law._ A principle formulated by Gregor Mendel with regard to
the inheritance of characteristics. Fenton, following Walter, states it
thus: “When two animals or plants unlike with respect to any character
are crossed, the offspring of the first generation will be apparently
like one of the parents in regard to the character in question. The
parent which impresses its trait upon the offspring in this manner
is called the _dominant_, while the one that fails to be visibly
represented is the _recessive._ When, however, the hybrid progeny of
this generation are in turn crossed with each other, they will produce
a mixed lot of offspring, one-fourth of which will be like the dominant
grandparent, one-fourth like the recessive one, and the remaining half
like the parents which resembled the dominant grandparent, yet failed
to breed true to it.”