Introduction.

be replaced by others. I was even tempted to suggest a theory of gases where, in place of the forces acting during collisions, there would be mere equations of condition In physics, these are constraints that limit the motion of a system, such as a bead on a wire. in the sense of Hertz's posthumous mechanics Referring to Heinrich Hertz’s "The Principles of Mechanics," published in 1894, which sought to explain all physical phenomena through hidden masses and motions rather than "force."; these are more general than those of elastic impact. However, I refrained from doing so, as I would only have had to make new arbitrary assumptions once again.

Experience teaches us that new discoveries have been guided almost exclusively by specific mechanical perspectives. Maxwell himself recognized the flaws in Weber's theory of electricity Wilhelm Weber’s theory relied on forces acting at a distance, which Maxwell replaced with field theory. at first glance; on the other hand, he cultivated the theory of gases with the greatest zeal and far preferred the method of mechanical analogies to that of pure mathematical formulas (as he expressed it).

Therefore, as long as clearer and better ideas have not been gained, we shall have to cultivate the old hypotheses of the specific theory of heat alongside the general theory of heat, and without prejudice to its importance. Indeed, if the history of science shows how often epistemological epistemological: relating to the theory of knowledge and how we distinguish justified belief from opinion generalizations have proven to be false, might not the currently fashionable trend—which is averse to every specific mental image—as well as the distinction between qualitatively different forms of energy, one day be recognized as a step backward? — Who can see into the future? Therefore, let the path be clear for every direction; away with all dogmatism, whether in an atomistic or anti-atomistic sense! Furthermore, by designating the ideas of the gas theory as mechanical analogies, we express clearly through the choice of this word how far we are from the notion that they correspond in every detail to the true nature of the smallest parts of matter.

We wish first to adopt the most modern standpoint of pure description and accept the well-known differential equations for the internal motions of solid and liquid bodies. From these it follows that in many cases—for example, in the collision of two solid bodies, in the movement of liquids in closed vessels, etc.—as soon as the shape of the bodies deviates even slightly from a geometrically simple—