century (1910). Up until now the phenomenon has not been completely covered by scientific thought and even less by experiment.12
Apparently there is not only one form of planetary atoms in a specific state. It is clear that for some chemical elements, for instance lead, isotopic mixtures can differ. This is caused by radioactive dissociation and specific conditions of the atoms’ migration. It is possible that there is another phenomenon related to it such as the influence of life – the change of isotopic mixtures in the biosphere – but this issue is not quite clear yet. Eventually it was understood that geochemical problems made up an inseparable part of the problems of cosmic chemistry, that the chemistry of Earth was one of the manifestations of planetary chemistry, and that the theory of the geochemical character of chemical elements, i.e., geochemistry, was distinctly different from mineralogy, the study of molecules and crystals formed by atoms.
Our idea of the unity of the chemical composition of the universe undergoes still deeper changes under the influence of the growing understanding of the fact that the atom is not the dominant form of manifestation of matter in the universe. Studying atoms gives no definite idea about the matter of the cosmos. Beyond atoms we can observe the realm of electrons, positrons, neutrons, free protons, and a series of unknown material particles dominating in mass. To a lesser degree these phenomena also cover the matter of the Earth, for instance the electrons of the ionosphere’s electric field. The electronic chemistry of general chemical physics must occupy the dominant place in cosmic chemistry and must take its place in the chemistry of our planet together with geochemistry and mineralogy.
Since the last century, considerable changes have taken place in our scientific notions about the research area of geochemistry and mineralogy – the geological substratum of the planet. In the first half of the nineteenth century. it was considered indubitable that geological phenomena could serve as the basis for conclusions concerning the whole Earth. The dispute between plutonists and neptunists was based entirely on this assumption. The thin surface film, our biosphere filled with life, seemed to get lost and forgotten in the mass of the planet. Slowly but steadily, from generation to generation, these notions disappeared, because it was gradually discovered that all the geologically studied processes relate only to the outer part of the planet, the Earth’s crust. Processes that had formerly been related to the inside of the Earth proved to be external.
Gradually the boundaries of the Earth’s crust were determined; they did not exceed the upper 100 kilometers. Geodesists were the first to take up this viewpoint, and as early as 1851 the English priest J. G. Pratt provided the foundations of the theory of isostasy; that is, the non-homogeneous structure of the outer part of the planet, the Earth’s crust, as opposed to the homogeneous structure of the deep layers of the planet. He pointed out that it was not the depth of the Earth but the Earth’s crust that was involved with the greatest phenomena we know on the surface of the Earth: the formation of mountain chains. Immediately, the English astronomer G. B. Airy (1855) expressed Pratt’s ideas more correctly, and explained them by the hydrostatic equilibrium of different heterogeneous parts of the Earth’s crust. Pratt’s ideas, formulated in a general form by the American geologist C. E. Detton thirty years later, gained scientific acknowledgment only in the twentieth century. Geologists, however, came to the same conclusions earlier and in a different way. Thanks to that insight, all views on geochemical problems changed clearly. The volcanic products, the products of life, and the sediments of the sea proved to be bodies of one and the same planetary field that, as well as the phenomena of life, is different from the large mass of the Earth. As a general geochemical understanding, the significance of life increased and changed essentially.
In that period of time, another revolution in our general worldview was taking place. The old idea of J. Dalton and W. Wollaston, its logical consequences which were perhaps not quite clear to themselves, became reality; the atom and the chemical element proved to be identical. In order to understand the atom, one had to study the chemical element. The atom became as real to us as the chemical element; it acquired flesh and blood and became a real body. This achievement of science took place in the twentieth century, but the late decades of the previous century, in spite of what contemporaries thought, were already leading the scientific mind toward this generalization. It is well known that by the end of the nineteenth century, the atomistic view of Earth’s environment seemed to be losing ground and was being replaced by dynamic ideas about the world. In reality it was a mirage; in reality the atomistic view has never been as influential in the scientific worldview as today. True, the atom in the new worldview has little to do with the atom of philosophers and even of physicists; it is the chemical element of chemists in the form of an atom.
All these changes had for the first time made it possible to embrace geochemical problems as a whole, as a special scientific discipline, and to separate geochemistry out as a science that studies the history of atoms (understood as the chemical elements on our planet). Actually, we are studying only its external envelope, the Earth’s crust. In particular, this separation of the new science was taking place more or less independently in different parts of the civilized world. In Washington, F. Clarke – a chemist from the American Geological Committee who had studied geological problems all his life – collected and arranged an enormous amount of material in his book, Data of Geochemistry, of which the first edition was published in 1908. This book exerted a great influence on scientific thought and was published in five editions (the last one in 1924).13
A huge amount of factual data is collected in this book. Clarke tries to give the exact numerical data concerning the history of the main chemical elements. Although in his youth (1872) he had been one of the first scientists who had dared to scientifically tackle the issue of the possibility of turning one chemical element into another in connection with their history in the cosmos, and although fifty-three years later he returned to these cosmogonic generalizations, in his Data of Geochemistry, he pursued not hypotheses and wide generalizations, but comparison and criticism of exact numerical data on the history of chemical elements in the Earth’s crust and in its processes. He was interested in the study of the composition of the sea, the average composition of rivers, and the study of the Earth’s crust; everywhere he introduced new numbers and critically revised the old ones.
Clarke’s book has in fact become the foundation for further generalizations and further geochemical work.14 It summed up and covered a tremendous amount of material connected with the numerically exact chemical, geological, and mining research on the American continent. At the same time, an American who had worked in Canada, his elder contemporary T. Sterry Hunt (1825–1892), was also attempting “the synthesis of the Earth,” as he put it. Sterry Hunt’s influence was great, but he left a lot of room for theoretical speculations which were not always successful. Clarke’s synthesis, which was being built at the same time and on a firm empirical basis, proved to be more solid.
Having collected the facts and having empirically generalized them into the new science of geochemistry, Clarke finished Bischof’s work in the twentieth century. His book gave a summary of the tremendous work of thousands of people over a long period of time. As early as 1882, his first calculations of the gross chemical composition of the Earth’s crust had appeared. After that, Clarke incessantly altered and improved them (for the last time in 1924, together with H. Washington). These data – Clarke’s numbers – did not influence the scientific mind for many years but were objected to, and were appreciated for their great significance only in the last decade. This significance may turn out to be even greater than Clarke thought if the resemblance of the outer envelope of our planet to the outer envelopes of other planets can be proven.
As we shall see below, Clarke followed the routes outlined by W. Phillips as early as in the beginning of the nineteenth century, and he was the first to seek not an approximate numerical estimation of the phenomena, but a concrete exact number. Clarke did not formulate the task of geochemistry distinctly and categorically as being the study of the history of the planet’s atoms, this trend in geochemistry appeared later and aside from his direction of thought. But thanks to the real significance of Clarke’s numbers in the new theories of atoms, to their influence on the physical
