to diminish, though it may conceivably increase in particular cases. Just as in matters political, change for the better is possible, but the tendency is for all change to be from bad to worse." Here BURBURY states what is practically true in all actual cases and thus furnishes an additional reason, if that were needed, for the legitimacy of the Probability method pursued by Boltzmann, and, another explanation of why the results obtained are in such perfect accord with experience.
As BURBURY'S remarks with respect to the nature of "elementary chaos" under consideration are always illuminating, we will, at the risk of repeating something already said, quote the following:
"The chance that the spheres approaching collision shall have velocities within assigned limits is independent of their relative position, and of the positions and velocities of all other spheres, and also independent of the past history of the system except so far as this has altered the distribution of the velocities inter se. In the following example this independence is satisfied for the initial state and, for the assumed method of distribution, has no past history.
"Example. A great number of equal elastic spheres, each of unit mass and diameter
, are at an initial instant set in motion within a field
of no force and bounded by elastic walls. The initial motion is formed as follows: (1) One person assigns component velocities
