found in the liquid state. Quicksilver. Formula: Hg.
_Mesozoic._ Relating to the geological period between the Paleozoic and
the Cenozoic.
_Metabolism._ The complete process of building up and breaking down
protoplasm in a living organism. The process of digesting and storing
nutritive matter and of excreting waste matter.
_Metal._ An element which replaces or is capable of replacing the
hydrogen of an acid. One of a class of substances typically ductile,
malleable, lustrous, translucent only through very thin layers,
conducting heat and electricity well.
_Metaphysics._ The branch of philosophy dealing with knowing and being.
This must disappear entirely as science advances.
_Metazoa._ All the complex animals. All the animals except the Protozoa.
_Metric system._ The decimal system of weights and measures generally
used in many countries, employed for many purposes by scientists
everywhere. A meter is about 1.094 yards. A kilometer is about .6214
of a mile. A cubic centimeter is about .061 of an inch. A kilogram is
about 2.204 pounds. The C. G. S. (centimeter-gram-second) system is
used in practically every science which deals with space, mass, and
time.
_Mho._ A unit of electrical conductivity.
_Microbe._ A very small organism; in popular use, a disease-producing
bacterium, a germ.
_Micro-._ Small, in many compounds.
_Mineral._ Pertaining to substances which are not organic. An ore.
_Mineralogy._ The science of ores.
_Miocene._ Relating to the middle division of the Tertiary (geological)
period.
_Mitosis._ Cell division and multiplication by the usual process.
_Mixture._ A mass of more than one sort of material which is not
chemically compounded or united.
_Molecule._ The smallest amount of a substance which can exist with the
properties belonging to the substance.
_Molybdenum._ A metallic element. Symbol: Mo.
_Momentum._ The quantity of motion of a moving body. It is equal to the
mass multiplied by the velocity.
_Monadelphous._ With the stamen filaments in a single bundle.
_Moniliform._ Jointed in such a way as to resemble a necklace.
_Monecious._ Hermaphrodite. Having male and female flowers on the same
plant.
_Monopoly._ Sufficient control to influence price.
_Monotreme._ One of the lowest order (Monotremata) of mammals.
_Monsoon._ A periodic wind. Specifically, such a wind in the Indian
Ocean.
_Moraine._ The mass of earth and other matter deposited by a glacier.
_Morphology._ The study of form (of organisms or of words).
_Motor._ Pertaining to a nerve and an impulse causing motion. Relating
to action and the consciousness of action. Pertaining to a muscle
causing action. A machine which causes motion, especially such an
electric machine or one which is comparatively small.
_Muscle._ A fibrous band or bundle which contracts to produce movement
in an animal body.
_Muscology._ The study of mosses.
_Mutation._ A sudden variation which may produce a new species.
_Mycology._ The study of fungi.
_Myriapoda._ A class of arthropods including the centipedes.
_Narcotic._ A substance which induces sleepiness.
_Nascent._ Just beginning, having special properties because of just
having been released from combination.
_Neap tide._ The tide at which the high water mark is the lowest.
_Nebular Hypothesis._ The hypothesis advanced by Laplace that (in the
words of F. W. Dyson) “a vast nebula--diffused tenuous matter--once
extended to the confines of the solar system, and under the influence
of gravitation slowly contracted.... As the contraction proceeded the
rotation necessarily increased, and rings or other masses were thrown
off which collected and formed planets.” Any of several more or less
similar hypotheses.
_Nectar._ A sweet fluid produced by plants.
_Neocene._ Relating to the later part of the Tertiary (geological)
period.
_Neodymium._ A metallic element. Symbol: Nd.
_Neolithic._ Relating to the later part of the Stone Age.
_Neon._ A gaseous element. Symbol: Ne.
_Nerve._ The rib of a leaf. A vein. One of the fibers or bundles of
fibers carrying impulses of sensation and motion.
_Neurosis._ Activity of the nerves. A functional disease attributed to
the nerves.
_Neutral._ Neither acid nor basic in reaction. Without sex organs.
_Nickel._ A metallic element. Symbol: Ni.
_Niton._ A gaseous element which occurs in radium emanation. Symbol: Nt.
_Nitrogen._ A gaseous element constituting about four-fifths of the
air. Symbol: N.
_Noble metals._ Metals which do not oxidize in air or oxygen. Among the
noble metals are gold, silver, and platinum.
_Node._ A knob or root or branch, where a leaf is usually borne. One of
the points where the orbit of a planet or comet and the ecliptic meet.
A point or line which is at rest in a vibrating body.
_Normal._ Conforming to a standard or type. The normal is not
necessarily superior to the abnormal.
_Nutritive._ Of value as food.
_Ohm._ An electrical unit of resistance. The resistance of a circuit in
which one volt produces one ampere of current.
_Oligocene._ Of the Tertiary (geological) period, between the Eocene
and Miocene.
_Ontogeny._ Individual development.
_Opsonic._ Causing bacteria to be consumed more readily by phagocytes.
_Optics._ The science of light and vision.
_Optimum._ The environment most favorable to the growth of a plant or
animal.
_Ordovician._ Relating to the Paleozoic (geological) period between the
Silurian and the Cambrian.
_Ore._ A native mineral from which a metal or metals may be extracted.
_Organic._ Living, or derived from a living organism. Relating to
all the carbon compounds except a few simple ones. Relating to an
organ. Affecting the structure of an organ--of a disease, opposed to
_functional_.
_Organism._ An organized being, plant or animal. A living individual.
_Osmium._ A metallic element. Symbol: Os.
_Ovary._ The part of the pistil which contains rudimentary seeds. One
of the two reproductive organs in which eggs are produced.
_Overtone._ A tone produced by secondary vibrations, as of segments of
a piano wire.
_Ovum._ An egg or female germ. Plural: ova.
_Oxidize._ Combine with oxygen.
_Oxygen._ An important gaseous element. Symbol: O. About one-fifth of
the air is oxygen.
_Paleo-._ In many combinations, old, ancient. Also: palæo-, palaeo-.
_Paleozoic._ Of the oldest geological periods. More usually, of the
era between the Mesozoic and the Pre-cambrian. The words designating
geological eras have been used differently by various scientists.
_Paleontology._ The science dealing with life in former geological
periods, with species now extinct but made manifest by fossil remains.
_Palladium._ A metallic element of the platinum group. Symbol: Pd.
_Parallax._ The apparent displacement of an object caused by the actual
change in the position of the observer, or by the assumption of two
different points of observation. The parallax is expressed in degrees
of an angle.
_Paralogy._ Mental illness.
_Parasite._ A plant or animal that derives nourishment or shelter from
another upon which, with which, or within which it lives.
_Parthenogenesis._ Reproduction without the union of male and female.
_Pascal’s Law._ The law formulated by Pascal which is fundamental for
the mechanics of fluids: A fluid under pressure exerts equal force upon
equal areas of surface.
_Pelagian_ or _pelagic_. Relating to the open sea. Pelagic organisms
are those which do not approach the shore.
_Penology._ The study of punishment for crime. If this science were
studied scientifically, perhaps it would cease to exist.
_Perennial._ Lasting for several years; specifically, lasting for more
than two years.
_Phagocyte._ A leucocyte which consumes disease-producing organisms.
_Phase._ The aspect of the moon or of a planet depending on the amount
of illumination. Position of variation with regard to a real or
assumed starting-point. An individual chemical in a mixture.
_Phenomenon._ Probably more familiar in the plural: phenomena.
Something which is perceived by the senses. An event of scientific
interest.
_Philology._ The science of language. The philologists have been
inclined recently to extend their science, so that it deals with
meaning, with folklore or traditional beliefs, and with various other
subjects which are more or less closely related to language.
_Philosophy._ Literally: the love of wisdom. Former: the sum of
knowledge, a complete system of knowledge, sometimes with emphasis
upon its use in regulating human conduct. Philosophy is now primarily
ethical. Durant insists that the growth of the various sciences makes
it all the more necessary to be concerned with philosophy, which
directs the proper use of knowledge. Religion, incidentally, is
concerned chiefly with the field indicated for philosophy, not with the
ground covered by the various sciences.
_Phonology._ The study of sounds in speech.
_Phosphorus._ A non-metallic element. Symbol: P.
_Photics_ or _photology_. The science of light.
_Photo-._ In compounds, light or photographic.
_Phyllo-._ In compounds, leaf. For instance, Phyllopoda: an order of
crustaceans with feet resembling leaves.
_Phylo-._ In compounds, tribe, race. As, phylogeny: racial development,
the natural history of a type.
_Phylum._ One of the largest divisions of animals or plants.
_Physics._ The science of matter and energy, not including fields which
are considered chemical or biological.
_Pistil._ The female organ of a flower, including style, stigma, and
ovary.
_Planet._ One of the bodies which revolve about the sun, including the
earth but not comets or meteors.
_Plant._ A living organism which is not an animal. One which does not
have sensation or voluntary motion. (This definition must be revised in
the light of recent investigations.) Specifically, one of the smaller
plants, excluding trees and shrubs.
_Platinum._ A metallic element. Symbol: Pt.
_Pleistocene._ Of the geological epoch before the Recent, in the
Quaternary period of the Cenozoic era.
_Pole._ One of the two points in the celestial sphere about which the
stars seem to revolve. One of the extremities of the axis of the earth.
One of the points on a magnet where magnetic force is manifested. The
anode or the cathode of a cell. The extremity of an axis of a spherical
or oval cell or organ.
_Politics._ The science of government. Popularly, the art of exploiting
democratic citizens, as practiced by office-holders and those who
control them.
_Pollen._ The substance discharged from a flower, fertilizing or male
grains.
_Pollination._ The carrying of pollen to the pistils.
_Polonium._ A substance found in pitchblende, perhaps an element.
_Poly-._ In compounds, many-. For example, polyadelphous: having the
stamens united in three or more bundles. Polyandrous: having at one
time more than one husband. Polygynous: having at one time more than
one wife.
_Postglacial._ Belonging to a later period than that of the glaciers.
Recent.
_Potassium._ A metallic element. Symbol: K.
_Potential energy._ Energy which is latent, not employed or in motion.
Energy which a body has because of its position.
_Poundal._ The force which can act upon a pound mass for a second to
give it a velocity of one foot per second, or which will give a mass of
one pound an acceleration of one foot per second each second.
_Practice._ What is true in theory works out in practice, all due
allowances for the influence of other theoretic laws having been made.
_Praseodymium._ A metallic element which occurs in rare minerals.
Symbol: Pr.
_Pre-Cambrian._ Relating to the geological eras before the Cambrian
period.
_Precipitate._ To change into liquid form. To cause a substance to be
deposited in solid form from a solution. To make a dissolved substance
insoluble. That which has been precipitated.
_Prehensile._ Used for grasping, suitable for grasping.
_Pressure._ The amount of exertion of force, expressed by the weight
upon a unit area.
_Primate._ A member of the highest order (Primates) of mammals,
including man and the monkeys.
_Property._ That which belongs to a whole class but is not used to
distinguish it from others. Characteristic. A legal right to wealth.
_Protean._ Variable, readily changing form.
_Proteid._ Protein, or member of a special class of proteins.
_Protein._ One of a class of complex organic substances consisting of
carbon, hydrogen, nitrogen, oxygen, and, in some cases, other elements.
All living cells contain proteins.
_Protoplasm._ The living matter of which all animal and plant cells are
formed.
_Protozoan._ A member of the phylum (Protozoa) of animals of the
simplest type. A one-celled animal.
_Pseudo-._ In many compounds, false, seeming, similar to.
_Psychiatry._ The treatment of mental disease.
_Psychical research._ The study of phenomena which are not considered
by scientists as realities, and which are explained by some persons as
due not to natural forces but rather to spirit as opposed to matter.
If such phenomena are explained by means of the laws of physics and
psychology, there is no need for special “psychical research.” There
seems to be no reason why we should postulate spiritual or vital force,
even if our knowledge is not yet sufficient to explain all phenomena
scientifically.
_Psychology._ The study of the mind; in practice, the study of
behavior. Literally: the science of the soul. Perhaps psychology is
not yet a true science, but this branch of knowledge is undoubtedly
becoming more scientific, in spite of strong philosophical and mystical
tendencies.
_Psychophysics._ The study of the relation between the mental and the
physical, between psychology and physics.
_Psychosis._ Mental derangement, especially when there is no apparent
brain or nerve injury. Consciousness, a conscious process.
_Pteridophyte._ One of a phylum (Pteridophyta) of flowerless plants,
including the ferns.
_Pure._ Unmixed, abstract. Pure science deals with general principles,
not with particular applications.
_Pyro-._ In compounds, fire-, fever-.
_Quantel._ An elementary entity of matter consisting of positive
and negative parts, moving in all directions with the velocity of
light, capable of passing through solids. (According to the theory of
Langmuir.)
_Quantity._ Anything which can be represented by means of a number. In
chemistry, the number of gram molecules.
_Quantum._ The unit of energy transmitted by radioactive bodies.
_Quaternary._ Belonging to the most recent geological period.
_Radical._ Pertaining to a root, growing out of or from a point close
to the root. An atomic group which remains unchanged during the
ordinary reactions of the compound of which it is a part.
_Radicle._ That part of the embryo of a plant which develops into the
main root. A rootlike subdivision of a nerve or vein. Sometimes a mere
spelling variation of _radical_.
_Radioactive._ Emitting invisible rays that penetrate opaque matter
and produce electrical effects. Radium and some other substances
are especially radioactive, but radioactivity is supposed to be
characteristic of all substances.
_Radium._ A metallic element. Symbol: Ra.
_Rarefaction._ Making less dense.
_Ray._ A line at right angles to the wave front in which various forms
of energy may be transmitted.
_React._ Tend in the reverse direction, enter into chemical
combination. Act because of a stimulus.
_Reaction._ An opposing force. A chemical change. The usual nervous
response.
_Real number._ A number representing a quantity and one of two opposite
directions or senses.
_Réaumur._ A thermometric scale with the boiling point of water at 80
degrees and the freezing point at zero.
_Recapitulation Theory._ The theory which was at one time generally
favored by evolutionists, still accepted by many biologists, that
ontogeny recapitulates phylogeny; i. e., that the development of the
individual is an abridgement of the natural history of the species to
which it belongs.
_Recent._ In geology, pertaining to the epoch still in existence.
_Rectify._ Purify, as by repeated distillation. (Important in the
chemistry of bootlegging.)
_Reduce._ Remove oxygen, which combines with another substance.
_Refract._ Deflect (light, for example) at an angle. Refraction is due
to varying velocity in two mediums.
_Relativity._ Dependence of one quantity or knowledge upon another.
The Theory of Relativity formulated by Albert Einstein, based upon
the principle that the universe is a four-dimensional (time-space)
continuum, includes the conclusions that there is no absolute length,
that unobstructed light rays have a constant velocity irrespective of
the relative velocity between the observer and the source of light,
that the velocity of matter can never reach the velocity of light
unless the matter becomes light, that the mass of a body depends on
its velocity.
_Reproduction._ Generation, the process of creating offspring of about
the same kind as the parents. Apparently the power of reproduction is
that which chiefly sets apart the living from the non-living. However,
the fact that an individual organism is incapable of reproducing or
taking part in reproduction does not show that it is dead.
_Reptile._ One of a class (Reptilia) of animals including snakes and
crocodiles. The Reptilia are vertebrate animals which breathe air.
_Resistance._ Non-conductivity, opposition.
_Rheo-_, Stream, Current-, in compounds, chiefly electrical terms. As
rheostat: a device for regulating current by controlling resistance.
_Rhizo-_, Root-, in compounds. As, rhizopod: one of a class (Rhizopoda)
of protozoa having psuedopodia (“false feet”) which resemble roots.
_Rhodium._ A metallic element. Symbol: Rh.
_Rodent._ One of an order (Rodentia) of mammals, including rats,
rabbits, squirrels, and other gnawing animals.
_Röntgen rays_ or _X-rays_. Forms of radiation produced when cathode
rays strike the walls of the tube or the surface of a body placed
within the tube.
_Root._ A part of a plant, not necessarily but usually growing
underground, which attaches it to supporting points and conveys
nourishment.
_Rubidium._ A metallic element. Symbol: Rb.
_Ruminant._ One of a division (Ruminantia) of cud-chewing or at least
herbivorous mammals with hooves.
_Ruthenium._ A metallic element. Symbol: Ru.
_Salt._ A compound in which all or part of the hydrogen of an acid
has been replaced by a metal, or by some other inorganic element or
radical. Common salt is one of the general class of salts, and it is
known to chemists as sodium chloride.
_Samarium._ A metallic element. Symbol: Sm.
_Saponify._ To turn a fat or oil into soap by combining it with an
alkali. The term also includes a wider range of reactions in which
hydrolysis is involved.
_Saturate._ To cause a substance to combine with or to absorb the
greatest possible amount of another substance. To neutralize.
_Scandium._ A metallic element. Symbol: Sc.
_Science._ Exact, organized, and usually generalized knowledge. A
special scientific field or system. Specifically, physical or natural
science, not including philology or sociology. It is best not to attach
too much importance to such a distinction. See also Art and Common
sense.
_Secondary._ In geology, Mesozoic. Relating to reactions or compounds
considered less important or less simple than those which are called
primary. Of later origin. Induced. Relating to a second part.
_Selenium._ A solid, non-metallic element. Symbol: Se.
_Semen._ The generative fluid of a male animal.
_Seminal._ Relating to seed, semen, reproduction, or germs.
_Seminiferous._ Carrying seed or semen.
_Sensation._ The consciousness of perceiving or seeming to perceive a
bodily state or an external object.
_Sentiment._ An emotionally-colored tendency or attitude.
_Sepal._ A segment of the calyx of a flower.
_Septum._ A partition, as between two hollow chambers of an organism.
_Sessile._ Attached directly by the base.
_Sex._ The condition of being male or female or both.
_Sheath._ Membrane, tissue, skin, or other tight-fitting cover.
_Shrub._ A woody plant smaller than a tree. A bush.
_Silicon._ A non-metallic element, solid in ordinary temperatures. The
compounds are extremely common. Symbol: Si.
_Silver._ A metallic element. Symbol: Ag.
_Simoom._ A hot, dry wind of western Asia.
_Simple._ Not compound. Consisting of a single cell, element, or
individual. Not divided or branched.
_Social._ Living in groups or as a part of a complex organism. Working
together. Relating to society.
_Social psychology._ The study of the behavior of human groups.
Incidentally, social psychology is an easier subject than individual
psychology for the investigator. Where is the man who has never been
influenced by other human beings?
_Sociology._ The science of society. The study of the development of
social institutions. As sociology exists now, it is scientific only in
small parts.
_Sodium._ A metallic element. The compounds are common, including
ordinary table salt (sodium chloride). Symbol: Na.
_Soil._ A fine earthy matter on the surface, in which plants can grow.
_Solid._ Relating to the condition of matter in which it has a stable
shape and volume, with some elasticity.
_Solution._ A mixture of substances which is the same throughout the
mass. We think chiefly of the solution of solids or gases in liquids,
but solutions entirely of gases are common, and of solids within solids
are possible.
_Somatic._ Relating to the body as a whole or to that part from which
no new individuals are developed.
_Sound._ Vibrations produced when some object is set in motion, causing
a stimulation of the organs and nerve centers of hearing.
_Species._ A group subordinate in classification to the genus. The
members of a species differ only in minor details. In logic, a class
may be a species one time and a genus another. In biology, the classes
remain fixed. _Homo sapiens_, the class which embraces all mankind, is
always a species.
_Specific gravity._ The ratio between the weight of a given amount of
a substance and the weight of the same amount of a standard substance,
usually water at the temperature where it is densest. For gases, there
are various standards.
_Spectroheliograph._ An instrument for photographing the sun by
daylight.
_Spectrum._ The image formed by rays of light which are separated into
their component wave-lengths. Less frequently, the phenomenon (not
entirely visual) produced when other forms of radiant energy are thus
split up.
_Sperm._ Semen.
_Spermary._ The organ where semen develops.
_Spore._ A minute organic body that develops into a new individual. A
single cell that becomes free and develops independently.
_Sporozoan._ One of a class (Sporozoa) of parasitic protozoans which
reproduce by means of spores.
_Sport._ A sudden and striking deviation from type. A mutation.
_Stable equilibrium._ Such a condition in a body that, if suspended
like a pendulum and pushed to one side, it resumes its original
position immediately below the point of suspension.
_Stamen._ The male (pollen-bearing) organ of a plant.
_Star._ A heavenly body. More usually, those that appear to be fixed
dots of light, including the sun but not the planets or meteors, are
included in the term. One of the “fixed” stars. The stars are either
named or numbered in various catalogues.
_State._ Condition, especially the being in solid, liquid, or gaseous
form. An organized political community.
_Statics._ The study of bodies at rest and forces in equilibrium; a
branch of mechanics. According to Einstein, no body is ever at rest.
_Statistics._ The systematic collection of numerical facts. The study
which deals with collection of this sort and with the interpretation of
statistics in the first sense.
_Stigma._ The part of the style or ovary-surface that receives pollen.
A small speck or mark.
_Stipule._ A small appendage to a leaf.