From astronomy our philosopher of reality passes on to mechanics and physics, and voices the lament that the mechanical theory of heat has not, in the generation since its discovery, been materially advanced beyond the point to which Robert Mayer had himself developed it, bit by bit. Apart from this, the whole business is still very obscure;we must "always remember that in the states of motion `,f matter, static relations are also present, and that these latter are not measurable by the mechanical work ... if previously we described nature as a great worker, and if we now construe this expression strictly, we must furthermore add that the self-equal states and static relations do not represent mechanical work. So once again we miss the bridge from the static to the dynamic, and if so-called latent heat has up to now remained a stumbling-block for the theory, we must recognise a defect in this too, which can least be denied in its cosmic applications" {D. Ph. 90}.
This whole oracular discourse is once again nothing but the outpouring of a bad conscience, which is very well aware that with its creation of motion out of absolute immobility it got irretrievably stuck in the mud, but is nevertheless ashamed to appeal to the only possible saviour, namely, the creator of heaven and earth. If the bridge from the static to the dynamic, from equilibrium to motion, cannot be found even in mechanics, including the mechanics of heat, under what obligations is Herr Dühring to find the bridge from his motionless state to motion? That would be a fortunate way for him to get out of his plight.
In ordinary mechanics the bridge from the static to the dynamic is -- the external impulse. If a stone weighing a hundredweight is raised from the ground ten yards into the air and is freely suspended in such a way that it remains hanging there in a self-equal state and in a condition of rest, it would be necessary to have an audience of sucklings to be able to maintain that the present position of this body does not represent any mechanical work, or that its distance from its previous position is not measurable by mechanical work. Any passer-by will easily explain to Herr Dühring that the stone did not rise of itself to the rope and any manual of mechanics will tell him that if he lets the stone fall again it performs in falling just as much mechanical work as was necessary to raise it the ten yards in the air. Even the simple fact that the stone is hanging up there represents mechanical work, for if it remains hanging long enough the rope breaks, as soon as chemical decomposition makes it no longer strong enough to bear the weight of the stone. But it is to such simple basic forms, to use Herr Dühring's language, that all mechanical processes can be reduced, and the engineer is still to be born who cannot find the bridge from the static to the dynamic, so long as he has at his disposal a sufficient external impulse.
To be sure, it is a hard nut and a bitter pill for our metaphysician that motion should find its measure in its opposite, in rest. That is indeed a crying contradiction, and every contradiction , according to Herr Dühring, is nonsense {D. Ph. 30}. It is none the less a fact that a suspended stone represents a definite quantity of mechanical motion, which is measurable exactly by the stone's weight and its distance from the ground, and may be used in various ways at will, for example, by its direct fall, by sliding down an inclined plane, or by turning a shaft.
The same is true of a loaded gun. From the dialectical standpoint, the possibility of expressing motion in its opposite, in rest, presents absolutely no difficulty. From the dialectical standpoint the whole antithesis, as we have seen, is only relative; there is no such thing as absolute rest, unconditional equilibrium. Each separate movement strives towards equilibrium, and the motion as a whole puts an end again to the equilibrium. When therefore rest and equilibrium occur they are the result of limited motion, and it is self-evident that this motion is measurable by its result, can be expressed in it, and can be restored out of it again in one form or another. But Herr Dühring cannot allow himself to be satisfied with such a simple presentation of the matter. As a good metaphysician he first tears open, between motion and equilibrium, a yawning gulf which does not exist in reality and is then surprised that he cannot find any bridge across this self-fabricated gulf. He might just as well mount his metaphysical Rosinante and chase the Kantian "thing-in-itself"; for it is that and nothing else which in the last analysis is hiding behind this undiscoverable bridge.
But what about the mechanical theory of heat and the tied-up or latent heat which "has remained a stumbling-block" for this theory?
If, under normal atmospheric pressure, a pound of ice at the temperature of the freezing point is transformed by heat into a pound of water of the same temperature, a quantity of heat disappears which would be sufficient to warm the same pound of water from 0° to 79.4° C, or to raise the temperature of 79.4 pounds of water by one degree. If this pound of water is heated to boiling point, that is, to 100° C, and is then transformed into steam of 100° C, the amount of heat that disappears, by the time the last of the water has changed into steam, is almost seven times greater, sufficient to raise the temperature of 537.2 pounds of water by one degree.
