Chr. Bohr and Heidenhain.—Its scientific form was given to it by Chr. Bohr, an able physiologist at Copenhagen, and by Heidenhain, a professor at Breslau, who was one of the lights of contemporary German physiology. The course of their researches led these two experimentalists, working independently, to submit to fresh investigation the ideas of Lavoisier and those of Bichat, on the relation of physico-chemical forces to the vital forces.
It was by no means a question of a general inquiry, deliberately instituted with the object of discovering the part played respectively by physical and physiological factors in the performance of the various functions. Such an investigation would have taken several generations to complete. No; the question had only come up incidentally. Chr. Bohr had studied with the utmost care the gaseous exchanges which take place between the air and the blood in the lungs. The gaseous mixture and the liquid blood are face to face; they are separated by thin membrane formed of living cells. Will this membrane behave as an inert membrane deprived of vitality, and therefore obeying the physical laws of the diffusion of gases? Well! no. It does not so behave. The most careful measurements of pressures and of solubilities leave no doubt in this respect. The living elements of the pulmonary membrane must therefore intervene in order to disturb the physical phenomenon. Things happen as if the exchanged gases were subjected not to a simple diffusion, a physical fact obeying certain rules, but to a real secretion, a physiological or vital phenomenon, obeying laws which are also fixed, but different from the former.
On the other hand, Heidenhain was led about the same time to analogous conclusions with respect to the liquid exchanges which take place within the tissues, between the liquids (lymphs) which bathe the blood-vessels externally and the blood which those vessels contain. The phenomenon is very important because it is the prologue of the actions of nutrition and assimilation. Here again, the two factors of exchange are brought into relation through a thin wall, the wall of the blood-vessel. The physical laws of diffusion, of osmosis, and of dialysis, enable us to foretell what would take place if the vitality of the elements of the wall did not intervene. Heidenhain thought he observed that things took place otherwise. The passage of the liquids is disturbed by the fact that the cellular elements are alive. It assumes the characteristics of a physiological act, and no longer those of a physical act. Let us add that the interpretation of these experiments is difficult, and it has given rise to controversies which still persist.
These two examples, around which others might be grouped, have led certain physiologists to diminish the importance of the physical factors in the functional activity of the living being to the advantage of the physiological factors. It would therefore seem that the vital force, to use a rather questionable form of language, withdraws in a certain measure the organized being from the realm of physical forces—and this conclusion is one form of contemporary neo-vitalism.
§ 4. Philosophical Neo-Vitalism.
Contemporary neo-vitalism has assumed another form, more philosophical than scientific, by which it is brought closer to vitalism, properly so called. We should like to mention the experiment of Reinke,[2] in Germany. Reinke is a botanist of distinction, who distinguishes the speculative from the positive domain of science, and cultivates both with success.
His ideas are analogous to those of A. Gautier, of Chevreul, and of Claude Bernard himself. He thinks, with these masters, that the mystery of life is not to be found in the nature of the forces that it brings into play, but in the direction that it gives them. All these thinkers are struck by the order and the direction impressed upon the phenomena which take place in the living being, by their interconnection, by their apparent adaptation to an end, by the kind of impression that they give of a plan which is being carried out. All these reflections lead Reinke to attach great weight to the idea of a “directing force.”
The physico-chemical energies are no doubt the only ones which are manifested in the organized being, but they are directed as a blind man is by his guide. It seems as if a double accompanies them like a shadow. This intelligent guide of blind, material force is what Reinke calls a dominant. Nothing could be more like the blas and the archeus of Van Helmont. Material energies would thus be paired off with their blas, their dominants, in the living organisms. In them there would therefore be two categories of force: “material forces,” or rather, material energies obeying the laws of universal energetics; and in the second place, intelligent “spiritual forces,” the dominants. When the sculptor is working his marble, in every blow which elicits a spark there is something more than the strong force of the hammer. There is thought, the volition of the artist, which is realizing a plan. In a machine there is more than machinery. Behind the wheels is the object which the author had in view when he adjusted them for a determined end. The energies spent in action are regulated by the adjustment—that is to say, by the dominants due to the intellect of the constructor.
Thus it is in the living machine. The dominants in this case are the guardians of the plan, the agents of the aim in view. Some regulate the functional activity of the living body, and some regulate its development and its construction. Such is the second form, the philosophical form, extreme and teleological, of contemporary neo-vitalism.