In the case of
gases, a molecular theory has been developed by Clausius and others,
capable of mathematical treatment, and subjected to experimental
investigation; and by this theory nearly every known mechanical
property of gases has been explained on dynamical principles; so that
the properties of individual gaseous molecules are in a fair way to
become objects of scientific research.
Now Mr Stoney has pointed out[1] that the numerical results of
experiments on gases render it probable that the mean distance of
their particles at the ordinary temperature and pressure is a quantity
of the same order of magnitude as a millionth of a millimetre, and Sir
William Thomson has since[2] shewn, by several independent lines of
argument, drawn from phenomena so different in themselves as the
electrification of metals by contact, the tension of soap-bubbles, and
the friction of air, that in ordinary solids and liquids the average
distance between contiguous molecules is less than the
hundred-millionth, and greater than the two-thousand-millionth of a
centimetre.
Pages:
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38