An apparent contradiction, for instance, to this law of demarcation between artificial products and the results of animal and vegetable life is presented by the existence in living creatures of substances like oxalic acid, formic acid, urea, uric acid, creatine, creatinin, and the like. None of these substances, however, has any effect on polarized light or shows any dissymmetry in the form of its crystals. These substances, it must be remembered, are the result of secondary action. Their formation is evidently governed by the laws which determine the composition of the artificial products of our laboratory, or of the mineral kingdom properly so called. In living beings they are the results of excretion rather than substances essential to life. The essential fundamental components of vegetables and animals are always found to possess the power of acting on polarized light. Such substances as cellulose, fecula, albumin, fibrin, and the like, never fail to have this power. This is sufficient to establish their internal dissymmetry, even when, through the absence of characteristic crystallization, they fail to manifest this dissymmetry outwardly.
It would scarcely be possible to indicate a more profound distinction between the respective products of living and of mineral nature than the existence of the dissymmetry among living beings and its absence in all merely dead matter. It is strange that not one of the thousands of artificial products of the laboratory, the number of which is each day growing greater and greater, should manifest either the power of turning the plane of polarization or non-superposable dissymmetry. Natural dissymmetrical substances--gum, sugar, tartaric and malic acids, quinine, strychnine, essence of turpentine, and the like--may be and are employed in forming new compounds which remain dissymmetrical though they are artificially prepared. It is evident, however, that all these new [{301}] products only inherit the original dissymmetry of the substances from which they are derived. When chemical action becomes more profound--that is, becomes absolutely analytic or loosening of the original bonds imposed by nature--all dissymmetry disappears. It never afterward reappears in any of these successive ulterior products.
"What can be the causes of so great a difference?" We quote from Pasteur's life by his son-in-law: "Pasteur often expressed to me the conviction," says M. Radot, "that it must be attributed to the circumstance that the molecular forces which operate in the mineral kingdom and which are brought into play every day in our laboratory are forces of the symmetrical order; while the forces which are present and active at the moment when the grain sprouts, when the egg develops, and when under the influence of the sun the green matter of the leaves decomposes the carbonic acid of the air and utilizes in diverse ways the carbon of this acid, the hydrogen of the water and the oxygen of these two products are of the dissymmetrical order, probably depending on some of the grand dissymmetrical cosmic phenomena of our universe."
For the first few years after this discovery Pasteur endeavored by every possible means to secure experimental modifications of some of these phenomena of dissymmetry. He hoped thus to learn more fully their true nature. Magnetic influences especially would, he hoped, enable him to pierce, at least to some degree, this fundamental mystery of nature. While acting as professor at Strasburg, he procured powerful magnets with the view of comparing the actions of their poles and, if possible, of introducing by their aid among the forms of crystals a manifestation of dissymmetry. At Lille, where he was for several years dean of the scientific faculty, he contrived a piece of clockwork intended [{302}] to keep a plant in continual rotary motion, first in one direction and then in the other. "All this was crude," he says himself, "but further than this I had proposed with the view of influencing the vegetation of certain plants to invert, by means of a heliostat and a reflecting mirror, the motion of the solar rays which should strike them from the birth of their earliest shoots. In this direction there was more to be hoped for."
He did not have time, however, to follow out these ingenious experiments. He became involved, as we shall see, in labors more than sufficient to take up all his time and all his energy. These labors were of great practical importance for France. Pasteur always insisted, however, that great discoveries will yet be made in following out this order of ideas, and that there is in this subject magnificent opportunity for young men possessed of the genius of discovery and the power of persistent work.
When, only a few years ago, Professor Duclaux, Pasteur's successor as the head of the Pasteur Institute, and himself one of the greatest living authorities on biological chemistry, wrote the story of the mind of the master, [Footnote 14] he said, of this subject of dissymmetry: "A living cell appears to us, then, as a laboratory of dissymmetrical forces, a bit of dissymmetrical protoplasm acting under the influence of the sun--that is to say, under the influence of exterior dissymmetrical forces. It presides over actions of very different kinds. It can manufacture, in its turn, new dissymmetrical substances which add to or take away from its energy. It can, for instance, utilize one of the elements of a paratartrate without touching another. It can manufacture crystalline sugar at one moment and consume it at another, laying by stores for itself to-day using them up to-morrow. In a word, the living cell [{303}] presents a marvellous plasticity, which exerts itself without the slightest disturbance by minimal deviations of forces due to dissymmetrical influence. Ah, if spontaneous generation were only possible! If we could only create living matter, raise up in the midst of inactive mineral material a living cell, then it would be easy for us to understand something more of vital manifestations and to comprehend better the mystery of dissymmetry."
[Footnote 14: L'Histoire d'un esprit, par M. Duclaux, Paris, 1896.]
But spontaneous generation is as far off as ever. Pasteur's discoveries in dissymmetry have brought us closer than ever before to the mystery of life. Scientists still hope, but it is with ever-waning confidence, that they may pluck out the heart of the mystery. Pasteur's own thoughts with regard to dissymmetry rose above even the lofty heights of mere earthly biology. He saw in it the great force that links the universe together. On one occasion, at the Academy of Sciences, he expressed himself as follows:
"The universe is a dissymmetrical whole. I am inclined to think that life, as manifested to us, must be a function of the dissymmetry of the universe or of the consequences that follow in its train. The universe is dissymmetrical; for, placing before a mirror the group of bodies which compose the solar system with their proper movement, we obtain in the mirror an image not superposable on the reality. Even the motion of solar light is dissymmetrical. A luminous ray never strikes in a straight line. Terrestrial magnetism, the opposition which exists between the north and the south poles of a magnet, the opposition presented to us by positive and negative electricity, are all the resultants of dissymmetrical actions and motions."