JOHANN WOLFGANGDOBEREINER, GOETHE~S CHEMICAL ADVISER WILHELM PRANDTL University of Munich, Munich, Germany Translated by R a l p h E. Oesper
Wenn rvir dich, o Vater sehen In der Werkststt der Nat,ur Denken wir: Der solche Sachen Hat so weislioh ausgedaeht, Sollte der nicht Mittel linden Und die Kunst, die frdhlich mscht? Und d a m , scheuend auf nsch ohen, Wiinschen, bester Vrtt,er, wir, Was die Menschen slle laben, Gliick und Lebens frcude dir.
JoHmiv WOLFGANG GOETAEcomposed this poem in December, 1816, when Johann Wolfgang Dohereiner, professor of chemistry a t the University of Jena, was sick and downcast as a result of overwork. To cheer up the patient, the poet suggested that the students honor their beloved teacher's birthday by a torchlight parade. One of them was assigned the pleasant duty of reciting these verses a t the celebration. Dobereiner was horn on December 13, 1780, a t the Bavarian town of Hof an der Saale in the Fichtelgebirge. Shortly thereafter, his father, a coachman, secured employment first as a servant and later as manager of an estate a t Miinchherg in Upper Franconia. Here the bright boy passed his boyhood in close contact with nature and agriculture, but received only the bare essentials of schooling. His father could not afford to provide him with any higher schooling and put him to farm work. The mother, however, who herself had an urge for learning and intellectual interests, encouraged the boy's desire to go on with his education. She arranged for lessons with the pastor in the neighboring village, and so a t the age of fourteen the youth was prepared to enter an apprenticeship in an apothecary's shop. After three years of training the young apothecary's assistant set out on his Wanderjahre to secure further experience, and after stops in various cities he eventually reached Strassburg. Even though he did not have the funds to enroll a t the university there, he found much scientific activity in the city. From time to time he attended lectures on various scientific topics, and filled the gaps in his education by self-study. He also learned the French language. Five years later he returned to his home, and a t the age of twenty-three he married Klara Knah, whom he had known from boyhood. Though he was now a fullfledged apothecary, he had neither the funds nor a
license to buy a druggist's shop. Consequently, he acquired an agricultural produce business and added to it the manufacture of pharmaceutical-chemical preparations. As early as 1803 he began to report his experiences with the technical production of white lead, sugar of lead, magnesium sulfate, etc., in the Neues allgemeines Journal der Chemie, whose new editor mas Adolph Ferdinand Gehlen. These papers brought Dobereiner to the attention of chemists, but the complaints of envious neighbors caused the loss of his license to carry on the business. Relatives then gave him a position in their textile mill, where he was put in charge of bleaching and dyeing. He studied the bleaching of cotton goods with alkali hypochlorite solutions, the preparation of caustic alkali from alkali sulfate, etc., and again reported his experiences in Gehlen's Journal. However, the continental blockade occasioned by the Napoleonic war made it necessary to close down the plant. Again without a job, Dohereiner took over the supervision of agricultural estates, where he especially modified the practices in brewing and distilling. I n the nearby town of Bayreuth he made friends with the professor of mathematics and physics, Johann Salomo Christoph Schweigger, who later (1811) edited the (Schweigger's) Journal fur Chemie und Physik as a continuation of Gehlen's Journal. However, the agricultural projects directed by Dohereiner were discontinued in 1810, and once more he was out of work. Almost 30, the father of a family, his savings were quickly used up, and in the midst of a war his lot was indeed a sad one. I n August, 1810, when the heavens seemed darkest, he was completely dumbfounded to receive notice from the Senate of the University of Jena that he had been nominated extraordinary professor in the philosophical faculty with the commission to teach chemistry and technology. The "Gesamt-Academie Jena," which jointly served the Saxon duchies of Weimar, Coburg, Gotha, and Meiningen had had a professorship in chemistry since 1789. This chair had been established by Duke Carl August of Saxony-Weimar with the collaboration of t,he Privy Councillor Johann Wolfgang von Goethe. It had been occupied with complete satisfaction to all for twenty years by Johann Friedrich August Gottling, who had come from the ranks of the apothecaries. This beloved teacher had died on September 1, 1809,
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and the Duke Carl August requested Gehlen to propose a successor to Gottling. Gehlen offered Dobereiner's name, but with little hope of success, since the latter did not possess even the ordinary school certificate of graduation, to say nothing of higher education or a doctor's title. Relying on Gehlen's recommendation, Carl August saw to i t that the faculty called Dobereiner. Only after he arrived in Jena did Dohereiner learn that as an academic teacher it was necessary for him to have the doctorate title. Accordingly, he petitioned the philosophical faculty to grant him a doctorate diploma gratis. He did obtain it at half the usual fee, and because of his poverty paid off this debt in installments, or as the faculty minutes read, "in rather smooth Laubthaler." The call to Jena was the greatest event in Dobereiner's life. It filled him with such profound gratitude to his patrons "the most illustrious gentlemen, and Goethe," that he filled his post in his beloved Jena with complete devotion of his talents and strength until the close of his life, refusing offers from five universities that at various times sought to win him for themselves, and despite the fact that throughout all his years in Jena he never was free of financial worries. The small state could not afford to pay him more than a meager salary, and he had to support not only his wife and his old mother but a brood of eight children and the house servants, and also meet necessary professional expenses. A t that time, von Goethe, as Privy Councillor and Minister of State, supervised the institutions of science and art in the duchy of Sachsen-Weimar-Eisenach. He and the duke had correctly grasped the importance of chemistry, which was then beginning to flourish, and they wished to promote this science for the benefit of their little country to the fullest extent compatible with its modest means. Weimar is only 12 miles from Jena, and on November 8, 1810, Dobereiner appeared a t the capitol city to intrcduce himself to his immediate superior. He made a favorable impression on the great poet. They spent two days discussing plans for equipping the chemical laboratory a t the university. At first it was located in the upper floors of the former palace a t Jena, and was fitted up with old chemical apparatus on hand a t Weimar, with material from Gottling's incumbency, and with books from the ducal library. Goethe laid great weight on the collection of demonstration material, especially important preparations and minerals, to be exhibited in glass cases for the purpose of lightening the demands on the memory and with the hope that they would lead to reflectful contemplation. The palace rooms assigned to the chemistry laboratory soon proved inadequate for the experiments that had been planned. Accordingly, in 1816 the authorities acquired a house and its large garden situated near the Neutor (New Gate) in Jena. Goethe had this building, which was known as the Hellfeld Haus after its former owner, fitted up for Dobereiner's needs. The ground floor contained a large room in which, from the
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The Hellfeld Haus.
Sketch by Gosthe
winter semester 182&21 on, Dobereiner conducted a public laboratory course. Later (1833) a new technical-chemical laboratory, for which Goethe had drawn the plans, was erected in the garden. This building, which was set directly on the ground, with no basement, was about 12 meters long, 5 meters high, and cost 700 thalers. In order to complete the fittings Dobereiner had to borrow 200 thalers in addition from his daughters' savings. "Of course there are still lacking some things that, considering the present state of chemistry, should be on hand in a laboratory devoted to instruction and new investigations, but I can wait and, if necessary do without, because I have learned Franklin's trick of sawing with a drill and drilling with a saw, in order that I mag carry on my experiments even under unfavorable conditions, and have proved that great results can come from experimenting even with small means. . ." mote the unassuming scientist to the supervisory board in 1834. The "new laboratory" next to the Hellfeld Haus, which furthermore served as his residence, was Dobereiner's laboratory until his death on March 24, 1849. He succumbed, after a brief but painful illness, to a
D6bereiner.s Laboratory
T o the right: The Hellfeld Haus: "new laboratory."
t o the left: behind the trees, the
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cancer-like destruction of the throat and the upper parts of the esophagus. At the time Dobereiner began to busy himself with chemical problems, the phlogistio hypothesis had been essentially abandoned in Germany. Gottling, his predecessor a t Jena, had acquainted the German chemists with the new French nomenclature as early as 1790 in his "Taschenbuch fiir Scheidekiinstler and Apotheker" and, convinced by his own experiments, had accepted the Lavoisier doctrines. Dobereiner had come to know the new theory during his stay in Strasshurg. Like his contemporaries of his own age, Humphry Davy (1778-1829) and J. J. Berzelius (17791848), Dobereiner also came under the influence of the epoch-making discoveries of galvanism (1780) and the voltaic pile (1800), and like Berzelius he also recognized the basic significance of stoichiometry, a term coined by J. B. Richter (1762-1807) to designate what he called the "art of measuring chemical elements." The three scientists therefore worked to a large extent in the same fields, Dobereiner with the most modest means. For many years he carried out "Stoichiometric studies" and determined the combining weights of numerous elements, i . e., he made what are now called "atomic weight determinations." He collected the first results in his stoichiometric tables, "Darstellung der Verhaltniszahlen der irdischen Elemente," published in 1816. As early as 1817, in the course of these studies, he came upon the idea, which, however, he did not publish until 1829 in Poggmdorffs Annalm der Physik und Chemie, under the title, "An attempt to group the elementary materials according to their analogy." He had found that the specific gravity and the "atomic weight" of strontia closely approximate the mean of the specific gravities and "atomic weights" of lime and baryta, and that in similar fashion soda lies between lithia and potash in the alkali group. Likewise, in the group sulfur-selenium-tellurium, the specific gravity of selenium is the exact mean of the specific gravities of sulfur and tellurium; and finally, he observed that the atomic weight of bromine is the arithmetic mean of the atomic weights of chlorine and the iodine. Thus Dohereiner was the first to discover the numerical relationships between chemically similar elements. As the principle of the grouping he took trinity-triasand gathered the elements into groups, which were designated as "triads" by Leopold Gmelin in his Handbuch der Chemie. Dobereiner's statements attracted no attention for a long time, but they were the start of the attempt to arrive a t a systematic classification of the chemical elements, which was continued in 1850 by Pettenkofer and brought to a close through the erection of the natural system of the elements by Lothar Meyer (1864-69) and D. I. Mendelejeff (186971). As early as 1821, and hence long before the discovery of the Faraday laws (1833), Dobereiner recommended the use of a simple galvanic cell for stoichiometric studies.
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In the course of his many years of experience in the fields of preparative and analytical chemistry, Dobereiner had frequent opportunities to discover new methods of procedure or to improve existing practices. In 1816 he recommended the use of ammonium carbonate or oxalate in the presence of ammonium chloride for the separation of calcium and magnesium, a method still in general use. Another discovery was the addition of powdered pyrolusite (MnOn) when oxygen is prepared by heating potassium chlorate. He also recognized that it seemingly remains unchanged and asked himself: What role does the pyrolusite play here? His most famous discovery came from his interest in platinum. In order to obtain a supply of this metal for the manufacture of laboratory vessels and also to recover the accompanying metals, Dohereiner began to work up two pounds of American platinum ore in 1812. His first efforts were directed toward the separation of the platinum metals. The discovery and extraction of platinum ores in the Ural Mountains, from 1823 on, greatly facilitated his studies in this field. The ducal court a t Weimar had close family connections with the court of the Czar, because Carl August's daughter-in-law, the crown princess Maria Paulowna, was a wealthy Russian grand duchess. Furthermore, she was a patroness of Dobereiner and had repeatedly made generous contributions to his laboratory. Consequently, he had access to large quantities of Russian platinum ore. While Dohereiner had already spent years on the chemistry of platinum, Humphry Davy, in London, during his studies of the nature of the flame (1817) observed that inflammable gases or vapors when mixed with air burn without producing a flame a t hot platinum or palladium gauze, with the result that the gauze glows because of the heat of combustion. About this same time, his younger cousin, Edmund Davy, found that a solution of platinum sulfate when boiled with alcohol produced a black powder-later called Platinschwarz by Dobereiner-which when moistened with alcohol, begins to glow so that the alcohol bursts into flame. He used this discovery to make a lighter, in which alcohol vapor mas set on fire by a piece of punk coated with platinum black. On repeating this experiment, Dohereiner discovered (1821) that platinum black causes alcohol to combine, a t room temperature, with the oxygen of the atmosphere to form a product (that he named "oxygen ether") and also acetic acid. From the former, Liebig isolated acetal (1832) and acetaldehyde (1835). On July 27, 1832, Dobereiner discovered that the spongy or pulverulent platinum, obtained by igniting ammonium platinum chloride, has the property of setting fire to a mixture of hydrogen and air or oxygen. The action took place a t room temperature, or even a t -lO°C. When he allowed hydrogen to issue from a gasometer through a capillary and impinge on platinum dust held one or two inches below the nozzle the metal became red or white hot almost immediately and the hydrogen caught fire. This discovery created a real sensation and was im-
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mediately tested and confirmed by numerous chemists and physicists. Berzelius declared i t the most brilliant discovery of its time. Dobereiner demonstrated it to the convention of the German scientists and physicians a t Halle on September 18, 1823. A direct result of this remarkable finding was the construction of the lighter that bears his name: the Dobereiner Feuerzeug. In this device, hydrogen, generated from zinc and sulfuric acid, streams through a narrow opening toward a holder in which platinum sponge is suspended on thin platinum wires. After the gas catches fire, the flame can be applied to a candle. Of course, the platinum sponge occasionally became inactive, but it could be easily revivified by heating. About 20,000 of these Dohereiner lighters were in use in Germany and England around 1828. They were replaced after the middle of the 19th century by phosphorus matches, and especially after the invention (1848) of "Safety" matches by Rudolph Christian Bottger, one of Dobereiner's students. To demonstrate the oxidation of alcohol to acetic acid, Dobereiner constructed an "acetous lamp," in which alcohol was supplied by a cotton wick to a small funnel containing platinum black. He also planned the technical production of acetic acid from alcohol by means of platinum black. In 1832 he reported that in the presence of platinum sulfur dioxide is converted to the trioxide by the oxygen of the air. However, Peregrine Phillips of Bristol had already (1831) secured an English patent on this process, whose technical importance had not been recognized by Dobereiner. In the further course of his investigations on platinum he also studied the chemical nature and the mode of action of platinum black. Eventually he came to the conviction that the platinum deposited from its salts or alloys by the wet method was "not a simple, hut a mechanical combination of this metal with compressed oxygen gas or, in other words, that the platinum reduced or isolated by the wet method has the property of absorbing and thus compressing a large amount of oxygen gas, and that it becomes capable of combining chemically with diverse readily oxidizable substances. He found further that this mechanical combination of platinum with oxygen decomposes a t the instant of its contact not only with alcohol and hydrogen, but also mood alcohol, formic acid, and other organic materials, and that i t is quickly formed again if atmospheric air or oxygen is allowed to act on the deoxygenated platinum, and that therefore in the processes of oxidation and acidification of alcohol, etc., platinum plays a role corresponding to the function of the nitrous gases in the process of sulfuric acid formation." Hence, Dobereiner had clearly comprehended that the reactions occurring between oxygen and oxidizable substances in the presence of platinum belonged to the group of chemical reactions which a t that time had not yet been collected under a special name, and for which ~erzelius in 1836 proposed the term "catalysis." Furthermore, Dobereiner's explanation of the catalytic action of platinum was accepted for a long time. He
Portable platinum lighter; ordinary platinum Lighter; aoetous or vinegar lamp; a s t e r produoer; eudiorneter.
certainly earned a place of honor among the scientists who have studied catalysis. He repeated his obsemations on platinum since 1824, described them in a comprehensi6e manner, and finally collected the whole in his book: "Zur Chemie des Platins in wissenschaftlicher und technischer Beziehung. Fiir Chemiker, Metallurgen, Platinarheiter, Pharmazeuten, Fabrikanten und die Besitzer der Dohereinerschen Platinfeuerzeuge" (Stuttgart, 1836). Dobereiner's earliest scientific studies dealt with the nature of carbon and its compounds. At the beginning of the 19th century, organic chemistry was in its first beginnings. At that period, the materials produced by the thermal decomposition of organic compounds, i. e., carbon monoxide and dioxide, methane, hydrogen, etc., were regarded as the building stones of the original compounds and attempts to regenerate the latter from such fragments seemed a reasonable endeavor. Dobereiner distinguished between plant and animal charcoal and regarded the former as a hydrogen and the latter as a nitrogen compound of carbon proper. Because of its behavior toward metals, he believed carbon to be a metallic element. In order to prepare pure carbon he placed a mixture of pine soot, powdered iron, and manganese oxide in a crucible, which was then heated, with exclusion of air, to the highest temperature of a potter's kiln. After dissolving away the iron-manganese alloy in acids there remained black-gray metallic shiny leaflets, which conducted the electric current and volatilized when heated in the air. He named this material carbon metal or carbonium. In modern terms, he had converted amorphous carbon into graphit.-. -..~ Dobereiner extended his stoichiometric studies to carbon compounds also and, like Berzelius, he found
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carbonic acid. He determined the ratio between the amount of sugar and its fermentation products, i. e., alcohol and carbon dioxide. As early as 1817, he made determinations of the sugar content of plant juices by measuring the volume of carbon dioxide produced when the samples were fermented. He also determined how much oxygen or air is required to convert alcohol into acetic acid. Dobereiner also constructed a theory of the organic compounds of vegetable origin on the basis of his stoichiometric findings, hut this was soon out of date. In addition to his scientific activities Dobereiner also served as expert consultant in all technical chemical matters to his sovereign, Duke Carl August of SachsenWeimar and the latter's minister, Goethe. He was appointed superintendent of all breweries, distilleries, vinegar factories, dyeworks, etc. At the request of his patron, he made effortsto replace foreign dyestuffs with homegrown products. For example, he prepared indigo from woad (Isatis tinetoria), madder from madder root (Rwbia tinctonam,), and safflo~ver,the coloring matter of Carthanzus tinetoria. He made suggestions for improving the manufacture of steel; he produced water gas for technicaI use; and, at Goethe's request, prepared illuminating gas from Ilmenau coal for a street illumination planned in honor of the duke. In Jena, where the world-famous Schott and Zeiss works \\-ere founded later, Dobereiner as early as 1828, in collaboration mith the court mechanician and optician, Friedrich Korner, carried out experiments on the preparation of optical glass (celestine and haryta glass). He wished to makc use of the great quantities of carbon dioxide released by the various fermentation industries for the that the law of constant proportions and Gay-Lussac's preparation of carbonated waters for table and balneolaw of combining volumes also apply to carbon com- logical purposes. However, all these plans and experipounds. In their analysis he used combustion with ments had no practical results, since the small duchy copper oxide, followed by gas volumetric determination of Sachsen-Weimar lacked the financial resources to put of the combustion products. them into practice on a profitable or even self-sustaining In 1816 he showed that the anhydrous salts of oxalic scale. Dobereiner, the scientist and technologist, who himacid-or rather, in the sense current a t that time, its anhydride-consists exactly of one volume COz and self had enjoyed no no~malschooling, was nevertheless one volume CO. He called it "carbonous acid" and an outstanding teacher. He had the ability to hold the attempted in vain to prepare it from these components. student's attention in his lectures, but in addition he Among the other studies which he made in the field gave them an opportunity to profit from his knowledge of organic chemistry, his investigations of alcoholic and practical experience by laboratory exercises. From fermentation and its products merit special attention. 1820 on, and hence considerably prior to Liebig in Although he did not know that fermentation is oc- Giessen, Dobereiner held at Jena a "chemical practical casioned by a living ferment, nevertheless he viewed it course" and thus created in the little state of Sachsenas a biological process which required particular super- Weimar an educational institution the like of which did intendence. As early as 1808, in Bayreuth, he was one not appear in large countries such as Prussia and Ausof the first to observe the fermentative conversion of tria until several decades later. He also wrote a numstarch paste into fermentable sugar. In 1812, during ber of widely used textbooks for chemistry and pharthe continental blockade which Napoleon imposed macy students, which, issued in small editions, have now against England, Dohereiner set up a t Tiefurt, near become quite rare. His students included not only the inventor of the Weimar, a small starch sugar factory, but there was soon no more need for it. He analyzed sugar and safety match, R. C. Bottger (vide supra), but also alcohol in 1816, and his results showed that both are Ferdinand Friedlieb Runge, the first investigator of compounds of carbonicacid (COJl andcarburetedhydro- coal tar and the founder of the coal-tar dye industry. gen (CH3, in the respective ratios of 3 :3 and 1 :3. He However, his most famous student was the poet made fruitless efforts to prepare sugar from alcohol and Goethe. He not only studied Dobereiner's textbook
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of chemistry but, as he notes gratefully in his "Tag und Jahresheften," permitted himself to be initiated in 1815 and 1817 by Dobereiner into the secrets of atoichiometry. Whenever Goethe stayed in his beloved Jena he visited Dobereiner in his laboratory, had experiments performed, and sought information about the latest discoveries. He also frequently invited Dobereiner to visit him in Weimar, so that he might receive scientific instruction. At the end of October, 1820, Dobereiner had to demonstrate for him Oersted's sensational discovery of the effect of the electric current on the magnetic needle, and on December 16, 1822, he met the discoverer of electromagnetism a t Goethe's house in Weimar. When the latter wrote his "Farbenlehre," Dobereiner had to perform for him many "chromatic" experiments, which were to serve as proofs in Goethe's color theory. On one visit to the laboratory, Goethe carried away a piece of platinum ore, and did not return it despite repeated reminders. When Dobereiner then complained to the duke, the latter replied: "Let the old mule go. I will ask the Czar for a new piece of platinum." Dobereiner was a born scientist who, closely linked
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with nature from his youth on, observed passionately, gathered experiences, evaluated them with clear understanding, and put them into their proper scientific setting. At the same time he was an idealist, poor in worldly possessions, but rich in knowledge, who, mithout thought of his own advantage, unselfishly gave of this wealth so that others might aid humanity. When an English manufacturer made him a very advantageous offer for the commercial exploitation of his lighter he declined; he had immediately given his invention to the world as a mark of homage to it and his science. "I love science more than money, and the knowledge that I have been of use to many mechanical artisans makes me happy." As early as 1813, Carl August promoted him to the rank of Bergrat (Mining Counsellor), and in 1818, when he was offered the chair of physics and chemistry a t the University of Halle, he mas made Hofrat (Privy Counsellor). The Knight's Cross of the Weimar House Order of Watchfulness or of the White Falcon was bestowed after the invention of the platinum lighter. In 1851 a monument was erected by the grateful city of Jena to the memory of Johann Wolfgang Dobereiner.
