meaning": (a) A
Nomenclature, or system of the names of all classes of objects, adapted
to the use of each science. Thus, in Geology there are names for classes
of rocks and strata, in Chemistry for the elements and their compounds,
in Zoology and Botany for the varieties and species of animals and
plants, their genera, families and orders.

To have such names, however, is not the whole aim in forming a
scientific language; it is desirable that they should be systematically
significant, and even elegant. Names, like other instruments, ought to
be efficient, and the efficiency of names consists in conveying the most
meaning with the least effort. In Botany and Zoology this result is
obtained by giving to each species a composite name which includes that
of the genus to which it belongs. The species of Felidae given in chap.
xvii. Sec. 7, are called _Felis leo_ (lion), _Felis tigris_ (tiger), _Felis
leopardus_ (leopard), _Felis concolor_ (puma), _Felis lyncus_ (European
lynx), _Felis catus_ (wild cat). In Chemistry, the nomenclature is
extremely efficient. Names of the simpler compounds are formed by
combining the names of the elements that enter into them; as Hydrogen
Chloride, Hydrogen Sulphide, Carbon Dioxide; and these can be given
still more briefly and efficiently in symbols, as HCl, H_{2}S, CO_{2}.
The symbolic letters are usually initials of the names of the elements:
as C = Carbon, S = Sulphur; sometimes of the Latin name, when the common
name is English, as Fe = Iron. Each letter represents a fixed quantity
of the element for which it stands, viz., the atomic weight. The
number written below a symbol on the right-hand side shows how many
atoms of the element denoted enter into a molecule of the compound.

(b) A Terminology is next required, in order to describe and define the
things that constitute the classes designated by the nomenclature, and
to describe and explain their actions.

(i) A name for every integral part of an object, as head, limb,
vertebra, heart, nerve, tendon; stalk, leaf, corolla, stamen, pistil;
plinth, frieze, etc. (ii) A name for every metaphysical part or
abstract quality of an object, and for its degrees and modes; as
extension, figure, solidity, weight; rough, smooth, elastic, friable;
the various colours, red, blue, yellow, in all their shades and
combinations and so with sounds, smells, tastes, temperatures. The terms
of Geometry are employed to describe the modes of figure, as ang