10. (Mus.)
(a) Produced by natural organs, as those of the human
throat, in distinction from instrumental music.
(b) Of or pertaining to a key which has neither a flat
nor a sharp for its signature, as the key of C major.
(c) Applied to an air or modulation of harmony which
moves by easy and smooth transitions, digressing but
little from the original key. --Moore (Encyc. of
Music).
{Natural day}, the space of twenty-four hours. --Chaucer.
{Natural fats}, {Natural gas}, etc. See under {Fat}, {Gas}.
etc.
{Natural Harmony} (Mus.), the harmony of the triad or common
chord.
{Natural history}, in its broadest sense, a history or
description of nature as a whole, incuding the sciences of
{botany}, {zo["o]logy}, {geology}, {mineralogy},
{paleontology}, {chemistry}, and {physics}. In recent
usage the term is often restricted to the sciences of
botany and zo["o]logy collectively, and sometimes to the
science of zoology alone.
{Natural law}, that instinctive sense of justice and of right
and wrong, which is native in mankind, as distinguished
from specifically revealed divine law, and formulated
human law.
{Natural modulation} (Mus.), transition from one key to its
relative keys.
{Natural order}. (Nat. Hist.) See under {order}.
{Natural person}. (Law) See under {person}, n.
{Natural philosophy}, originally, the study of nature in
general; in modern usage, that branch of physical science,
commonly called {physics}, which treats of the phenomena
and laws of matter and considers those effects only which
are unaccompanied by any change of a chemical nature; --
contrasted with mental and moral philosophy.
{Natural scale} (Mus.), a scale which is written without
flats or sharps. Model would be a preferable term, as less
likely to mislead, the so-called artificial scales (scales
represented by the use of flats and sharps) being equally
natural with the so-called natural scale
{Natural science}, natural history, in its broadest sense; --
used especially in contradistinction to mental or moral
science.
{Natural selection} (Biol.), a supposed operation of natural
laws analogous, in its operation and results, to designed
selection in breeding plants and animals, and resulting in
the survival of the fittest. The theory of natural
selection supposes that this has been brought about mainly
by gradual changes of environment which have led to
corresponding changes of structure, and that those forms
which have become so modified as to be best adapted to the
changed environment have tended to survive and leave
similarly adapted descendants, while those less perfectly
adapted have tended to die out though lack of fitness for
the environment, thus resulting in the survival of the
fittest. See {Darwinism}.
{Natural system} (Bot. & Zo["o]l.), a classification based
upon real affinities, as shown in the structure of all
parts of the organisms, and by their embryology.
It should be borne in mind that the natural system
of botany is natural only in the constitution of its
genera, tribes, orders, etc., and in its grand
divisions. --Gray.
{Natural theology}, or {Natural religion}, that part of
theological science which treats of those evidences of the
existence and attributes of the Supreme Being which are
exhibited in nature; -- distinguished from revealed
religion. See Quotation under {Natural}, a., 3.
{Natural vowel}, the vowel sound heard in urn, furl, sir,
her, etc.; -- so called as being uttered in the easiest
open position of the mouth organs. See {Neutral vowel},
under {Neutral} and Guide to Pronunciation, [sect] 17.
Note: Historically, chemistry is an outgrowth of alchemy (or
alchemistry), with which it was anciently identified.
2. An application of chemical theory and method to the
consideration of some particular subject; as, the
chemistry of iron; the chemistry of indigo.
Note: This word and its derivatives were formerly written
with y, and sometimes with i, instead of e, in the
first syllable, chymistry, chymist, chymical, etc., or
chimistry, chimist, chimical, etc.; and the
pronunciation was conformed to the orthography.
{Inorganic chemistry}, that which treats of inorganic or
mineral substances.
{Organic chemistry}, that which treats of the substances
which form the structure of organized beings and their
products, whether animal or vegetable; -- called also
{chemistry of the carbon compounds}. There is no
fundamental difference between organic and inorganic
chemistry.
{Physiological chemistry}, the chemistry of the organs and
tissues of the body, and of the various physiological
processes incident to life.
{Practical chemistry}, or {Applied chemistry}, that which
treats of the modes of manufacturing the products of
chemistry that are useful in the arts, of their
applications to economical purposes, and of the conditions
essential to their best use.
{Pure chemistry}, the consideration of the facts and theories
of chemistry in their purely scientific relations, without
necessary reference to their practical applications or
mere utility.