Jacobi Betserius (1779-1848), the first advocate of the symbols of the elements in chemistry and master of quantum chemistry, was born on August 20, 1779, in a small country village called Vifissunda in southern Sweden. He made important contributions to the development of chemistry by accepting and developing Dalton's atomic theory; determining the atomic weights of more than forty elements using oxygen as a standard; adopting modern symbols for the first time and publishing a table of atomic weights for the elements known at the time; discovering and producing several elements for the first time, such as silicon, thorium, and selenium; being the first to use the concept of organic chemistry; and being the first to use the concept of electrochemical dichroism. He was the author of the theory of "electrochemical duality", discovered the phenomenon of "isomerism" and was the first to propose the concept of "catalysis". His outstanding achievements made him a renowned authority on chemistry in the 19th century.
Name: Jacobi Betzelius
Nationality: Sweden
Birthplace: Vifissunda
Birthday: 1779
Death: 1848
Occupation: Scientist
Graduate School: Uppsala University
Products: Textbook of Chemistry
By his work, he was known as the first person to be published in the 19th century. /p>
Biography
Early childhood
Bethelius the Younger's parents were both farmers. When he was 4 years old, his father died of an illness, and his mother took him and his 2-year-old sister and remarried to a kind-hearted priest. Two years later, Bezelius' mother also died. Fortunately, his stepfather, who already had five children of his own, nurtured and educated the siblings as if they were his own. The priest was not rich, but soon he still did his best to raise a considerable sum of money and hire a learned governess for his seven children. While the governess was educating the children, the pastor took great care to satisfy the children's desire for knowledge, and often led them on excursions specifically for educational purposes. There were all kinds of plants along the creek, and in the clear water, fish were swimming and spitting bubbles, and little shrimps and crabs were burrowing and touching among the pebbles. The scenery along the creek varies throughout the year, and traveling along the creek is certainly a very attractive game for children. Betserius enjoyed it even more, especially since his stepfather was always there to guide and help him in his observations. Gradually he began to love nature with all his heart and soul, and sometimes he would lie down on the soft grass by the river and look up at the white clouds in the sky, and he felt as if he were already a part of nature.
Secondary school
In 1793, at the age of 14, Betserius entered the Lyceum of Linchpin. He did not study very hard for the complicated social science courses; but for the natural science courses, he showed great interest, often collecting specimens of all kinds of plants and animals, and liked to go hunting. Under the guidance of a new museum teacher who had just returned from an academic trip to the West Indies, Betserius began a more systematic study of the flora and fauna of the Rinchepin region. Throughout high school, he impressed his teachers as a gifted young man with broad ambitions but a quick temper.
University
After graduating from high school, Betzelius wished to continue his studies, and his stepfather agreed. in September 1796, at the age of seventeen, Betzelius traveled to Uppsala, Sweden's old university town. He passed the entrance exams and became a student at Uppsala University. Since his stepfather was unable to provide him with more money, his life was quite hard. In order to make a difference in his living conditions, Betserius went to work as a tutor for others. Although his income was rather meager, this self-supporting life developed his strong will and love of labor. In order to give the children of immigrants from different countries, Betzelius began to learn French, German and English, it is because of this self-study experience, so the knowledge of these languages in his later use of multi-language research in a variety of scholarly works played a great role in helping.
In the fall of 1798, Betzelius, a university student, was awarded a scholarship so that he would have more time to study what he liked without having to run around for a living. Soon he passed his exams in his own specialty, medical philosophy. Up until this point, Betserius had had little interest in what he would later spend his life doing, chemistry.
It was an exam that finally prompted Baetzelius to put his energies into chemistry. On an exam in his third year of college in all subjects, he came in last in his chemistry class, and would likely have been expelled if he hadn't excelled in his other subjects. From then on, not to be outdone, Betzelius began to study chemistry on his own initiative. At this time, the young man began to study the textbook "Fundamental Principles of Antiflammatory Chemistry" by the German chemist Gitaniel. It was an easy-to-understand textbook. It was after studying this book, Betzelius later recalled, that his interest in chemistry grew, and his mind was filled with all kinds of chemical experiments and chemical knowledge.
At that time, Lavoisier's doctrine of oxygen was penetrating into chemical theory and beginning to replace the outmoded kinetics. There was a heated debate between the proponents of the kinetics theory and Lavoisier's theory. In the Swedish scientific community, which was still dominated by the kinetics theory, Betzelius's teachers believed in the old view, while their student accepted Lavoisier's doctrine. Bezelius prepared large quantities of oxygen in his laboratory and often conducted experiments in front of his classmates on the combustion of various substances in oxygen. For these students, this was the earliest experiment that introduced them to Lavoisier's doctrine of oxygen.
In his constant experiments, Betserius deepened his interest in chemistry. At the time, chemistry was not taken very seriously at Uppsala University, and few undergraduates wanted to dedicate themselves to the subject. But Beckerius had by now fallen in love with chemistry, and began to solve his own problems in studying certain chemical phenomena. 1799 was spent in a glass store, where he learned from an Italian the art of soldering glass and making glassware. This skill, which was extremely important for laboratory work, always amazed his students in the future. In the winter of that year, he worked as an assistant to a doctor in the area where the Medway mineral water came from, and in the winter of 1800, Betserius performed a chemical analysis of the Medway mineral water, which he used as the title of his dissertation.
Teaching career
This was the time when, in the field of electricity, the Italian gangster invented the voltaic cell, which produces a continuous electric current. Soon after, Betserius, who was receptive to new ideas, also built a Voltar battery and used it to study the physiological and medical utility of electric currents. With this device he succeeded in restoring dexterity to a sick hand of an invalid. The experience of these experiments became the basis for his doctoral dissertation, and in May 1802, Betzelius defended his doctoral dissertation in public at the University of Uppsala, thus completing everything necessary to obtain the degree of Doctor of Medicine. In the same year, the Royal Swedish Medical Society appointed Betzelius, who had just turned 23, as a lecturer in medicine and pharmacy at the Stockholm Medical School. From there, he began his teaching career.
In 1807, at the age of 28, Betserius was appointed professor of chemistry and pharmacy. At this time there were only three professors in the medical department of the medical school where he taught, so each professor had to teach several courses. Betzelius offered courses in medicine, botany, and pharmacy, and soon afterward he offered courses in chemistry. In the beginning, his pharmacy classes were very popular with the students, but very few people came to his chemistry classes. This was due to the fact that chemistry professors at that time emphasized only verbal lectures and usually did not perform any demonstrations or experiments. This method of teaching chemistry is traditional in many universities. Verbalizing the properties and compositions of substances without visual experiments of chemical reactions was not only difficult for the lecturers, but also for the students, who found such abstract chemistry classes very boring and difficult to understand. Therefore, it can be imagined that the chemistry class is not popular.
Bethelius tried to change this situation. He greatly increased the number of experiments in his lectures and introduced visual chemistry experiments into the classroom. Soon, the classroom where he taught chemistry gradually filled up with students who came to listen to him. His method of teaching chemistry was soon adopted by many other universities. In addition to his intense teaching activities, Betzelius was also actively involved in scientific research. 1802, he conducted research on electrochemistry, and in February 1803, he summarized the results of his research into a thesis, which included all of the basic principles of the theory of electrochemistry that Betzelius would later put forward. In the same year, in the course of his research on the decomposition of compounds, Betzelius, together with the national chemist Hirschinger,**** discovered the new chemical element cerium, and at the same time accurately determined the properties of this new substance. Thus, the previously unknown 24-year-old Jacob Beckerius became a major figure in the chemical world. Betzelius made a name for himself in the world of chemistry.
Publications
Bethelius and Hirschinger edited and published the periodical Physics, Chemistry, and Mineralogy from 1806 to 1818, which became increasingly influential in physics and chemistry, and in which Bethelius frequently published his various research results.
In 1806, Betserius took it upon himself to write a textbook of physiological chemistry. It was in this year that he first introduced the concept of "organic chemistry" into his teaching, and in 1808 he undertook the preparation of the "Textbook of Chemistry", which was to be studied by generations of chemists in many countries, and which made a great contribution to the development of science. Beginning in 1807, and for the next six years, he also carried out studies to determine the basis of the composition of various salts, acids, and oxides with other substances.
Because of his great contribution to science and education, in 1808 he was elected a member of the Swedish Academy of Sciences, and in 1810 was elected president of the Swedish Academy of Sciences. With his heavy workload, Bezelius did not take these honors too seriously, and he continued to carry out his scientific research and teaching work in a practical manner.
As a scientist, Bezelius paid great attention to understand the latest scientific research progress in the world, he actively and foreign scientists to carry on the continuous contact, which further expanded his scientific point of view of the breadth and depth. At the beginning of his scientific activities, he had already established correspondence with many famous scholars, such as Bertore of France and David of England, etc. In the summer of 1812, Bezelius visited the Royal Society of England at the invitation of David, the president of the Royal Society of England, and through David's introduction, he also got acquainted with many outstanding representatives of the Society. In the next five months, Betzelius and David conducted *** with the chemical research, achieved a lot of *** knowledge, and each other to correct some of the other's erroneous views, and further deepen his and David's academic ties. 1818 spring, Betzelius due to excessive fatigue and became ill, the doctor and friends suggested that he could temporarily stop the chemical research, to foreign countries for convalescence travel. He heeded this advice and took a long trip abroad, visiting England, France, Switzerland and Germany. During his travels, he met many great scholars in Europe. He stayed in Paris, France for 10 months, and the French scholars exchanged research topics, from which Betzelius got a lot of very useful insights. 1820 October, he returned to Stockholm, and began a new scientific research.
Bethelius had already become a world-famous scholar. The scope of his research was extremely wide, and there was hardly a great problem in chemistry that he had not taken part in studying.
In order to better summarize the development of science at that time, starting in 1821, he set out to publish the Annual Reports of Progress in Physics and Chemistry. Until his death, 27 issues of the annuals were published, and they were the most authoritative digests on chemistry, physics and mineralogy in the first half of the 19th century.
Betzelius set himself the lofty goal of widely publicizing the achievements of science when he embarked on the publication of the annuals, believing that his efforts would surely promote the development of production and contribute to the welfare of the people. In the first issue of the annual report, he wrote in the name of the Academy of Sciences: "By the continued publication of these treatises or reports on the sciences, it will be possible for the intellectual class of the country to attain its ultimate aim - which is to recognize more closely the progress of human knowledge, to attach more importance to the study of practical sciences, and thus to apply the results of their researches more extensively to the benefit of the people. application of the results of their researches to the ordinary arts and crafts which are beneficial to the laborer, and in this way the prosperity of production and the improvement of the standard of living of the laborer will certainly be promoted."
The second task that Betserius set himself was to unite the forces of scientists of all countries in the promotion of science through this digest publication. He pointed out that the publication of an annual journal not only facilitates the summarization of work already done, but also allows research to be conducted on a new subject.
The Annual Report was published in 27 issues, each of which was a thick book, with the largest issue containing 800 pages of text. In editing the Annals, Betserius did more than merely excerpt the voluminous scientific treatises; he sought to select the most important of them for the development of science. As he once put it, "The fruit plucked from the garden of science, like the farmer's harvest, is often the ****ed product of work, luck, and favorable opportunity. In connection with the former it is only the gathering of facts in the daily routine that is associated with it, so that science is always slow in moving forward. Science sometimes takes greater than usual strides, and in most cases such strides are the result of opportunities well utilized, and sometimes of brilliant research by rare geniuses. Discoveries such as Elstedt's discovery of the electromagnetic effect; the thermoelectric phenomenon studied by Guibic; Faraday's discovery of electromagnetic spinning; Mickelite's discovery of the homocrystalline phenomenon of objects; and de Bleigner's discovery that platinum has the property of causing vaporization up to the point of ignition at ordinary temperatures are all tremendous steps forward that are extremely rare in science."
Discovery of the elements
In 1807, when the medical faculty of Stockholm University needed a lecturer who could teach chemistry, he applied and was immediately accepted. It was only then that Betzelius realized that his unintentional discovery of a new element was an important academic achievement. In 18O8, he wrote a chemistry textbook for his students, changing it again and again, and only took it out for publication fifteen years later, which was later translated into French, German, and English, and widely used in universities in Europe and the United States.
In 1808, Betzelius analyzed blood and found that hemoglobin contained iron, and analyzed various foods and found that spinach contained a large amount of iron, so he suggested that eating more spinach could improve physical strength and promote the production of blood. This research result was ridiculed by many people at the time: spinach is green, blood is red, how can eating green supplement red? Betselius did not argue; he continued to study the chemistry of physiological metabolism. Little did he know that he had inaugurated an important discipline of physiochemistry. In 1805, he wrote: The functioning of the human brain is the greatest mystery of nature, and so many chemical reactions are involved in it that it takes only one of them to go wrong for a man to go mad; and every time I unraveled one little chemical reaction in the brain, it was a great step toward knowing God.
Soon after, Betzelius suggested that it was lactic acid, not acetic acid, that caused the soreness in the muscles. He also discovered that lactic acid had an optical left-rotation and right-rotation difference, a molecule that had the same molecular formula but a differently arranged structure, which he called isomerism. In 1817, he analyzed a new element in the underground residue of a lead smelting furnace, which he named selenium (Selenium), the word meaning moon, because selenium was distinguished from the slag, as the moon is divided from the earth. Later he discovered a new element from a Norwegian pit called _, and named it _ (Thorium).
In 1818, Betzelius presented his most famous work, the determination of atomic weight. When he studied the oxides of the various elements, he found that each element had a certain weight and proportion to make up various substances, and he worked out the atomic weights of the forty-five known elements on the basis that an atom of oxygen weighs sixteen grams per mole. In 1826, he set down the symbols of various atoms in Latin, and discharged the atomic weight table, which was the earliest determination of atomic weight and its periodic table. Why were the chemical elements written in Latin? According to Berzelius, the common words of the day changed their meaning over time, while the non-spoken Latin left its original meaning. Today all chemical elements are named in Latin.
Even though Betselius was internationally renowned for his chemical achievements, he struggled financially. He lived for long periods in a basement, a small enough room, and from time to time some of his students came to discuss their homework with him, borrowing the living room to sleep in at night when it was too late. Betzelius snored loudly when he slept, but the students were used to it. Betzelius' wife, Elisabeth Poppius, was the daughter of the pastor of his church. When the bride returned from her honeymoon, she realized that her husband's home was almost a beggar's house, with more than two dozen students sleeping and lying in every corner, and uncleared dishes and clothes stacked so high that the couple had to clean up together.
The couple had no children, so they raised their students as children. Many of these students later became outstanding chemists, such as the first synthesis of urea Wohler (Wohler), in the iron ore in the discovery of the new element lithium (lithium) Arfwedson (Arfwedson), the discovery of the new element vanadium (vanadium) of the Shaverston (Sefstrom), the discovery of new elements of the glistening (lanternum) of the Monsanto (Mosander), the discovery of the new element of the glittering (lanternum), the discovery of the new element of the glittering (lanternum) of the Monsanto (Mosander). Mosander), discovered the new element _ (holmium) and manganese (thulium) Nilsson (Nilsson) and so on.
Bethelius wrote: In my eyes, the student is more important than any achievement. As for me, I am content to wake up with a ceiling over my head and a floor under my feet. In his later years, in his last speech at the Royal Swedish Academy of Sciences, Betzelius said, I am full of gratitude to God, and I feel that I am one of the happiest of men. He died on August 7, 1848, the seventh day of the eighth month. His life was not left blank, because so many of the spaces on the periodic table of atoms, he filled in.
Personal Achievements
Symbols to Represent the Chemical Elements
Bethelius's greatest feat in the field of chemistry was that he was the first to advocate the use of elemental symbols to represent the various chemical elements. He proposed that the Latin names of the chemical elements be used to represent the elements. If the first letter is the same, the first two letters are used to distinguish them. For example, Na and Ne, Ca and Cd, Au and A1. This is the chemical element symbol system that has been used to this day. His system of symbols for the elements was publicly published in the Annals of Philosophy, edited by Thomson in 1813. A year later, in the same publication, he wrote another article on the rules for writing chemical formulae. He labeled the numbers of various atoms with numbers in the upper right-hand corner of the element symbols. Examples include CO2, SO2, H20, and so on. Betzelius's method of representing element symbols and chemical formulas was far simpler and clearer than the previous method of using small circles by Dalton and others, and was therefore quickly accepted by the scientific community.
In the development of the atomic theory
Bethelius believed that in order to establish the atomic doctrine the atomic weights of as many elements as possible should first be measured with the greatest possible accuracy, and in 1814 he published a table of atomic weights containing 41 elements, which was increased to 45 elements in 1818, and to 50 elements in 1826. The latter table was practically the same as the present values (except that the values for the alkali metals and silver were twice the modern values). He discovered several new elements: cerium (1803), selenium (1817), thorium (1828). He also proposed a new system of symbols for the elements, which is used to this day.
In electrochemistry
Bethelius proposed the electrochemical duality theory in 1814: compounds are all composed of two components with different electrical properties (i.e., positively and negatively charged), pioneering the exploration of the interrelationships between the atoms in a molecule. Successful in the study of the properties of metals and nonmetals, and in explaining the nature and preparation processes of inorganic compounds.
Research on chemical affinity led to the establishment of the doctrine of electrochemical dualism by Betzelius, who had made a careful examination of the process of electrolysis in the dry years, and was particularly impressed by the opposite charges at the poles of the electrolytic tank, and by the attraction and repulsion of the charges to each other, which prompted him to resolve to apply the above viewpoints on electricity to the analysis of compounds grouped together in the Hundred Days and the mechanism of the chemical reaction. After more experimental investigations, he proposed in 1811, from the electrical point of view, a theory of chemical affinity which was considered to be more plausible, namely, his theory of electrochemical duality. Based on the duality in electricity and the experimentally proven fact that salt can be decomposed by electric current into alkali and acid, he related the concept of acid and alkali to the polarity of electricity, and argued that alkali is formed from the oxides of metals, which are positively charged: oxides of non-metals are negatively charged, and are capable of forming acids, and that there is also gravitational force at work between the two oxides, and that the interaction results in the formation of salt. For example, calcium oxide is cathodically charged, carbon dioxide is negatively charged, and calcium carbonate is formed when the two interact. He then extended this polarity to the elements, envisioning that each atom carries both a positive and negative charge, with oxygen being the most negatively charged element, potassium being the most positively charged, and the other elements being in between according to the strength of their negative (or positive) charge. Elements can interact with each other because they are attracted to each other by their opposite charges. For example, oxygen, the most electronegative element, is attracted to the other elements and thus combines with them. However, the oxides thus formed are not neutral; they are also electrically charged. This is because unequal charges cannot be completely neutralized. Thus, as already mentioned, the oxides of metals are cathodically charged, and those of non-metals are anionically charged. According to the assumptions of Betserius, material particles are always charged, and remain so even after chemotaxis, and the affinity with which matter interacts is the electric attraction. Considering electricity as the nature of material particles, this understanding is much deeper than that of David, who only stayed at the surface. Bezelius the chemical and electrical nature of matter are unified within the same material properties, through the electrical changes in matter to recognize the chemical changes in matter, the two changes organically linked, which is an important development of thought on chemical substances, the understanding of chemical processes.
The dualistic theory of electrochemistry is basically in line with the actual process of electrolysis, and in turn provides a more satisfactory explanation of the concept of affinity that enables salts to combine and acids and bases to neutralize their effects. The theory was simple and clear, it explained many chemical phenomena, and it was extremely easy for chemists to understand it. So this theory soon became a popular theory that won the approval of the vast majority of chemists. Later, with the development of organic chemistry, especially in the study of substitution reactions, electrochemical dualism gradually revealed its own shortcomings, was criticized, and a new doctrine emerged.
Organic chemistry
Bethelius first proposed the name "organic chemistry" in 1806. He discovered racemic tartaric acid and recognized the phenomenon of isomerism due to the fact that it had the same chemical composition as tartaric acid but different physical properties, and in 1835 he discovered catalysis and named it.
Bethelius was the outstanding chemist who pioneered the field of organic chemistry.In 1814, Bethelius proved by precise experiments that organic matter also obeyed the law of definite composition. This began the in-depth study of organic matter. He first quoted the concept of "organic chemistry". However, due to the scientific conditions at that time, the object of organic chemistry research can only be extracted from the natural plant and animal organisms of organic matter, that is, only from organic matter to manufacture organic matter. This gives people a kind of illusion, it seems that organic matter are "living things" or "living things", and only in a kind of non-material "life force" under the action can be formed, and can not be synthesized in the laboratory by chemical methods. It cannot be chemically synthesized in a laboratory. Obviously, this "vital force theory" and the electrochemical dualism of Betzelius bound the development of organic chemistry. However, when Wille synthesized urea in 1828, Betzelius was greatly inspired, and he thought that he had also discovered silver fulminate and silver cyanate, which were two substances of the same composition but with different properties, and was mistakenly believed to be due to experimental errors at that time. After Wille, he found a similar situation with tartaric and gluconic acids, and he felt compelled to propose a new concept. "I propose to call substances of the same composition but different properties 'isomeric' substances", he said. The discovery of the phenomenon of isomerism and its theoretical elucidation was an important step in the development of the theory of the composition and readiness of substances, and it began the study of the problems of molecular structure and contributed to the development of organic chemistry.
In analytical chemistry
He pioneered gravimetric analysis. He was the first to isolate silicon (1810), tantalum (1824), and zirconium (1824); he exhaustively studied the compounds of tellurium (1834) and the compounds of rare metals (vanadium, molybdenum, tungsten, etc.). He greatly improved the methods of analysis (analysis with rubber tubes, water baths, desiccators, washing bottles, filter paper, blowpipes) and combustion analysis (1814).
Bethelius was one of the most famous analytical chemists of his time. He introduced many new analytical methods, new reagents and new instrumentation into analytical chemistry for the determination of atomic weights, resulting in an unprecedented increase in the accuracy of quantitative analysis. He had carefully studied and improved various analytical operations. For example, he had pointed out that the fastest filtration speed is when the cone angle of the funnel is 60 degrees, and the filter paper should not be higher than the funnel, otherwise the solvent will evaporate quickly at the edge of the filter paper, making it difficult to wash out the precipitate. Betzelius has done a long and systematic study of mineralogy. In his quantitative analysis of minerals, he found that most of them are "siliceous" (silica). Silica and other metal oxide-ready compounds are the main components of minerals. Bezelius named the minerals containing such compounds "silicates". And all kinds of silicic acid according to its composition to do the classification, this classification is still used today. 1814 he published on the minerals of the new pure chemical classification of the paper, caused great attention in the academic world, immediately translated into English and German. At the same time in the mineral research, he also discovered some new elements. For example, cerium was discovered in 1803; selenium was discovered in 1817; thorium was discovered in 1828. Also discovered silicon, francium, tantalum, germanium and so on.
Chemical education
Bethelius was also a great chemical educator. He attached great importance to the training of chemical talents. He had compiled a chemistry textbook *** three volumes, in 1816, shortly after the first edition, was translated into French and German. During Betzelius's lifetime, the book was printed in Sweden in five editions. It is one of the most complete, systematic and popular textbooks on chemistry. It was read by thousands of young chemists over a period of more than 30 years. Betserius fascinated scientists with his vast knowledge and insight into the correct evaluation of experimental data. He was always revamping old methods and creating new ones, and made no secret of the fact that all his accomplishments were bursting into textbooks, paving the way for young scholars to move forward. A large number of chemists, such as Wille, studied under Betserius, who was one of the internationally recognized authorities on chemistry at the time.
Betzelius devoted his life to science, and he married for the first time at the age of 56. His wife Johanna was only 24 years old, is the Swedish Minister of State Poppius a thousand gold, before the wedding Betzelius was awarded the baronial title, when they married, they held a luxurious wedding. Government officials, scientists, socialites and his students came to congratulate them. After their marriage, Betserius continued to bury himself in scientific research. He lectured at the university while staying in the laboratory, and found time to write the Annual Review In 1836, he also published a paper in the journal Annals of Physics and Chemistry, which first introduced the concepts of "catalysis" and "catalyst" used in chemical reactions; again, it was he who introduced the concepts of "catalyst" and "catalysis" used in chemical reactions; and it was he who introduced the concepts of "catalysis" and "catalyst" used in chemical reactions. In 1836, he also published a paper in the Journal of Physics and Chemistry in which he first introduced the concepts of "catalysis" and "catalyst" used in chemical reactions, and in 1841 he was the first to propose the term "homogeneous". Because of the long-term intense work and often contact with toxic chemicals, Betzelius health suffered great damage, accumulated fatigue into disease, in August 7, 1848, in Stockholm, died at the age of 69 years. His death was not only a great loss to the Swedish people, but also a great misfortune to the internationalized academic community. The Swedish Academy of Sciences and the Swedish government held a solemn funeral for him.
Writings
Bethelius wrote A Course of Chemistry (2 vols., 1808-1812) and The Chemical Action of Electricity and the Theory of Chemical Proportions (1814).
Bethelius's name, which will remain forever in the history of chemistry in the world, and his great scientific life, will be a model for future generations of chemists.