Geochemistry and the Biosphere. Vladimir I. Vernadsky
Читать онлайн книгу.
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 and chemical thought of the twentieth century, his work has completely entered notions that were forming outside the realm of his thought. His geochemistry corresponded to the chemical and physical geology of Bischof but it met a different scientific environment.
The notion of geochemistry as a science about the history of terrestrial atoms appeared as a background to the new atomistics, chemistry and physics, in close connection with the idea of mineralogy typical of the Moscow University in 1890–1911. Both in teaching and in scientific mineralogical work there, most attention was paid to the history of minerals – their genesis and their change – which usually occupied a second rank in the mineralogy of schools of higher education at that time. With such a presentation of mineralogy, geochemical problems were presented on a larger scale, and were considered more important15 than in the common university courses of inorganic chemistry. Gradually, the work of the Mineralogy Chair of the Moscow University, and later the work related to it at the Mineralogy Museum of the Academy of Sciences, was more and more directed toward geochemistry. The name given by Clarke immediately found content here (although different from his own) and fruitful ground. The phenomena of life, and the mineralogy of sedimentary rocks in connection with radioactivity and general issues concerning the properties and character of atoms, occupied a considerable place. In 1912 in Moscow, in the university named after Shaniavsky, A. E. Fersman delivered the first university course of this new science. Furthermore, a series of A. E. Fersman’s and Ya. V. Samoylov’s works (1870–1925) have firmly established the traditions of geochemical work in our country.
By the twentieth century, the study of ore deposits, which had made great progress by that time, contributed greatly to the creation of geochemistry. The close connection between geochemical problems and insights about ores, which had led to the generalizations of Bischof, Breithaupt, and Elie de Beaumont in the previous century, has never been interrupted. But in the new century it acquired quite a different appearance due to the progress of chemistry, the unusual deepening of technology, and the great scope of extracting old metals and introducing new metals into the structure of human economy and life. In our century this phenomenon has acquired an extraordinary form: that of the global economy.
The works of the Frenchman, L. de Launay, and the German, A. Stelzener (1840–1895), were of great influence and posed geochemical problems. But considering the problems of the theory of ore deposits or applied mineralogy, most significant in the creation of the field of geochemistry are the works of the Norwegian, I. Focht (1858–1932), which are closely connected with the century-long mineralogical research based on the nature of Fennoscandia, and the works of North American mining engineers such as C. Van Hise and W. Lindgren. They connected the problems of geochemistry to that of ores, and in this way gave it a great practical value. This applied significance of geochemistry is growing rapidly during recent years. It manifests itself in our country as well, but we have to say that the conditions for its correct development are not favorable here.
Modern geochemistry is closely connected with the work and thought of another scientist – Prof. V. M. Goldschmidt – who in 1930 created the most powerful scientific center of geochemical work in Göttingen, Germany, although he himself was a product of the century-long scientific traditions of the Norwegian school of mineralogy. From 1914 to 1930, V. M. Goldschmidt, disciple of the outstanding mineralogist V. Brögger, was a professor in Christiania (now Oslo), where he created a mineralogical and geochemical institute with a high level of scientific thought. The Institute of Göttingen made further progress. The nature of Fennoscandia gave the mineralogical work in that country quite a unique flavor; it is an area of ancient crystalline rocks, and radioactive minerals are also present.
Often they are quite unusual in beauty and manifestation, distinctly different from all others in their outer form, unique in color, shine, and chemical composition, and also in such physical properties as metamic structures, compounds of uranium and thorium, rare earths, titanium, niobium, tantalum, zirconium, and hafnium. The school of chemists and mineralogists, which was here for centuries, covered this most difficult group of terrestrial bodies and discovered in the native material a quantity of new minerals and new elements. Bercelius, proceeding from this native material, applied his thought and exact methods to the whole area of inorganic chemistry of the twentieth century.
At the end of the century, Brögger synthesized the mineralogical work of the Fennoscandian and German scientists with reference to the same natural bodies. W. C. Brögger (born in 1851), a man of rare knowledge and exactitude of work, is equally prominent in geology, paleontology, and crystallography. He is a first-class researcher both in the field and in the laboratory; he connected the chemical study of minerals with their crystalline structure, developing in this field the ideas of another Norwegian scientist, the chemist and mineralogist T. Hjortdal (1839–1925).
Brögger’s disciple, V. M. Goldschmidt, therefore approached geochemical problems in surroundings full of traditions. The deeper geospheres of the Earth’s crust that are located beyond the stratisphere and the biosphere drew his attention; they constitute the largest part of the substance of our planet open to research. Solid matter acquired a special significance, and due to a new specification of roentgenometric methods, led to creation of crystal chemistry, in which Goldschmidt played an important role. Working in this direction, and taking into consideration the processes of elements’ migrations in the vectorial solid medium, Goldschmidt introduced into geochemistry a notion fraught with many consequences: the notion of the chemical elements’ behavior, as conditioned by their structure. He pointed out the regularities of their