This equation, which is mathematically deducible from the kinetic theory of gases, expresses the behaviour of gases, the phenomena of the critical state, and the behaviour of liquids; solids are not accounted for.
He supposes that the law of evolution is deducible from the law of persistent force, and includes in force what is now called energy.
While it is evident that some such conclusion must follow from the attempt to regard the cognitive consciousness as made up of disconnected feelings, it is equally clear, not only that the result is selfcontradictory, but that it involves certain assumptions not in any way deducible from the fundamental view with which Hume starts.
In the paper which immediately follows, he gives the oft-quoted expression for the difference of slope (dp/d9) 8 -(dp/de) 1 of the vapour-pressure curves of a solid and liquid at the triple point, which is immediately deducible from (21), viz.
The lengths ds, ds are proportional to the velocities of the points to whose paths they belong, and the proportions of those velocities to each other are deducible from the construction of the machine ~v the principles of pure mechanism explained in Chapter I.