The human species

by A. de Quatrefages

It is in this sense, and in this sense alone, that I have used above the expressions Force and Life. Astronomers consider gravitation the unknown cause of the movement of the stars; I consider Life as the unknown cause of the phenomena which are characteristic of organised beings. It may be that both gravitation and Life, as well as the other general forces are merely as x, of which the equation has not yet been discovered. I shall presently return to these considerations.

Be this as it may, whatever our real ignorance, whatever the Cause of which we are here treating, and though Impulsion should one day replace Attraction in our Theories, the facts would still remain the same. The stars would still be distributed through space, and subject to the laws of Newton and Kepler; they would still constitute a perfectly distinct whole, in the part assigned to the bodies which compose it, and in the nature of the relations which unite them. They would still form the Sidereal Kingdom.

This kingdom is then characterised by a general phenomenon, the Keplerian Movement, which may be attributed to a single force, namely that of gravitation.

IV. Let us now return to the Earth, the only celestial body which we can study in detail. Modern discoveries, however, judging from the relation of the elements and their mutual action, make it almost certain that the greatest similarity exists between the stars distributed in space, between all those at least which form part of our heavens.

Let us first establish the fact that upon our globe we again meet with the Keplerian Movement in falling bodies. Attraction is here represented by Weight. Gravitation reappears with all its laws, acting upon grains of dust as it acts upon worlds. The parts of the whole, of cosmos, as Humboldt would have said, cannot escape from the force which governs the whole.

But upon the surface of our Earth and in its interior, as far as we have been able to penetrate either by direct observation or scientific induction, we notice the appearance of other movements which are not subject to the laws of Kepler or Newton; phenomena appear which are entirely new and perfectly distinct from those due to gravitation. They are the physico-chemical phenomena. From their number and their difference in character they were long attributed to the action of distinct forces which were called Electricity, Heat, Magnetism, etc. Modern science, however, by transforming, so to speak, one into the other, has demonstrated their original unity. Physicists refer them all to nothing more than so many manifestations of the undulations of ether. The vibration of the latter is then the fundamental phenomenon from which all the others rise.

But this ether is absolutely hypothetical; its nature is perfectly unknown; no one knowing whence it acquires this quantity of movement, which, according to actual theory, should be subject neither to increase nor diminution. Now, in reality, we have here the Unknown cause of all physico-chemical phenomena. For this reason, and also for convenience, we shall give a name to this unknown cause, to this force, and call it Etherodynamy (Ethérodynamie).

But is not Etherodynamy only a particular form, a simple modification, or an effect of gravitation? Are not these two forces only different manifestations of a more general force? Many eminent men are much inclined to admit one or other of these hypotheses. Still, up to the present time, the facts do not seem to me to shew much agreement with them. Etherodynamy is displayed even in space and among the stars by variable, localised and temporary phenomena; the action of gravitation is one, universal and constant. Man has always been able to exercise a certain amount of control over the former; he can produce at will light and heat; modern science cannot act upon the second. We can neither augment nor diminish, reflect or refract, or polarise weight; we cannot arrest its action. Even in the fall of bodies the regularity in the acceleration of the motion proves that the cause of this movement is subject to no alteration. Here then is no transmutation of force similar to that in a machine worked by electricity or heat.

But whatever be the progress of science, and though M. de Tessan’s theory should be confirmed by experiment, the difference between the phenomena would not be diminished; the conclusions to be drawn from the facts in connection with the question we are here discussing would remain the same.

It is scarcely necessary to remark that the physico-chemical phenomena produced by etherodynamy can act upon masses or be exclusively molecular. They are in all cases similar to those which depend upon gravitation, they are subject to invariable laws and are always repeated in a similar manner when produced under similar circumstances.