I have shown that the electric particles and the fluid they form by their conjunction possess an inertia of a special nature differing from that of matter, which, joined to other properties, allows us to consider electricity in all its forms as composing an intermediate world between matter and the ether.
We shall again meet with the properties of this intermediate when we compare the laws of the flow of material fluids with those which regulate the distribution of the electric fluid. The differences between these different fluids are too visible for it to be necessary to indicate them at length. The electric fluid possesses a mobility which allows it to circulate in a metallic wire with the speed of light, which would be impossible for any material substance. It escapes the laws of gravitation while the equilibria of material fluids are governed by these laws alone, etc.
The differences are therefore very great, but the analogies are so likewise. The most remarkable of them is formed by the identity of the laws governing the flow of the material fluids and of the electric fluid. When one knows the former one knows the latter. This identity, which has taken some long time to establish, has now become classic. The most elementary treatises lay stress at every page on the assimilation which can be established between the distribution of electricity and that of liquids. They are careful, nevertheless, to point out that this assimilation is symbolical, and does not apply in every case. On looking a little closer into the matter, it has to be acknowledged, however, that it is in no wise a question of a simple assimilation. In a recent work the learned mathematician Bjerkness has shown that we have only to employ a certain system of electrical units for “the electric and magnetic formulas to become identical with the hydrodynamic formulas” (Les Actions Hydrodynamiques a Distance).
A few examples will at once make evident the resemblance of these laws. To give them more authority , I borrow them from a work of Cornu, published a few years ago (Correlation des Phenomenes d’Electricite Statique et Dynamiique).
It must first be remarked that the fundamental law of electricity, that of Ohm ( i = e/r ) might have been deduced from that movement of liquids in conduit pipes the properties of which have long been known to engineers.
~~Gustave Le Bon