ngs
of _equal_ lengths would yield the octave, fifth and fourth, when
strained by weights having certain definite ratios; and they did not
progress much beyond this. In the one of which cases we see geometry
used in elucidation of the laws of light; and in the other, geometry and
arithmetic made to measure the phenomena of sound.

Did space permit, it would be desirable here to describe the state of
the less advanced sciences--to point out how, while a few had thus
reached the first stages of quantitative prevision, the rest were
progressing in qualitative prevision--how some small generalisations
were made respecting evaporation, and heat, and electricity, and
magnetism, which, empirical as they were, did not in that respect differ
from the first generalisations of every science--how the Greek
physicians had made advances in physiology and pathology, which,
considering the great imperfection of our present knowledge, are by no
means to be despised--how zoology had been so far systematised by
Aristotle, as, to some extent, enabled him from the presence of certain
organs to predict the presence of others--how in Aristotle's _Politics_
there is some progress towards a scientific conception of social
phenomena, and sundry previsions respecting them--and how in the state
of the Greek societies, as well as in the writings of Greek
philosophers, we may recognise not only an increasing clearness in that
conception of equity on which the social science is based, but also some
appreciation of the fact that social stability depends upon the
maintenance of equitable regulations. We might dwell at length upon the
causes which retarded the development of some of the sciences, as, for
example, chemistry; showing that relative complexity had nothing to do
with it--that the oxidation of a piece of iron is a simpler phenomenon
than the recurrence of eclipses, and the discovery of carbonic acid less
difficult than that of the precession of the equinoxes--but that the
relatively slow advance of chemical knowledge was due, partly to the
fact that its phenomena were not daily thrust on men's notice as those
of astronomy were; partly to the fact that Nature does not habitually
supply the means, and suggest the modes of investigation, as in the
sciences dealing with time, extension, and force; and partly to the fact
that the great majority of the materials with which chemistry deals,
instead of being ready to hand, are made known only by the