Gottfried Wilhelm Osann and ruthenium/Gottfried Wilhelm Osann ja ruteenium.
LIFE AND ACTIVITIES OF GOTTFRIED WILHELM OSANN BEFORE HIS TARTU PERIOD
Gottfried Wilhelm Osann was born in Weimar, Germany, on 27 (26) October 1797 as a son of Friedrich Heinrich Gotthelf Osann (1753-1803), State Councillor of Saxony . His mother was Amalie Caroline Friederika, born Hufeland (1766-1843). After the early death of her husband she married the Secretary of State of Weimar Christian Gottlieb von Voigt. Osann's stepfather belonged to the famous circle of literates, the men of letters, led by J. W. Goethe, which formed in a great deal the further life of young Osann and his two brothers. The eldest brother Emil Osann (1787-1842) became a well-known specialist of curative mineral springs and was medical professor of Berlin University. Friedrich Gotthilf Osann (1794-1858) was an expert of ancient languages and professor of philology, first at Jena University and then until his death at Giessen University .
G. W. Osann's interest in physics and chemistry was encouraged mostly by J. W. Goethe, who had given an essential contribution to the development of chemistry at Jena University and studied himself the relationship between light and colour. Osann started to study chemistry at Berlin University, but after a year and a half continued alternately at the universities of Jena, Erfurt, and Erlangen. He graduated in Jena in 1819. After graduation he was employed as docent of theoretical and experimental chemistry, physics, and stoichiometry at Erlangen University. In that period his first printed paper was published--a speech held on 18 June 1819 at a festival on the sports ground of Erlangen . In 1821 Osann returned to Jena University and graduated there as doctor of philosophy. His dissertation was about the nature of chemical affinity--Natura affinitatis chemicae (Fig. 1). In 1821-1823 Osann worked at the philosophical faculty of Jena as a docent. That was the period when pure chemistry was separated from pharmacy and pharmaceutical chemistry. Osann delivered lectures on theoretical physics and chemistry and taught also experimental chemistry. He based in his work on the textbooks by E. G. Fischer (2) (Lehrbuch der mechanischen Naturlehre, second edition, Berlin and Leipzig, 1819) and J. W. Dobereiner (3) (Anfangsgrunde der Chemie und Stochiometrie, Jena, 1819) .
In 1821 Osann completed his monograph Beitrage zur Chemie und Physik and published it in Jena . The "rediscovered" platinum (4) and its catalytic properties investigated by professor Dobereiner attracted Osann's interest. This evidently inspired him in his later work with platinum ores in Tartu.
In 1823 Osann returned to Erlangen where he gave lectures on physics. He refused the offer from Konigsberg University to take the post of professor of physics and mineralogy, mostly due to the lack of interest in mineralogy. In autumn 1822, Gustav Ewers, Rector of Tartu University, came to Jena University looking for a new chemist. Jena University had already graduated three later chemistry professors of Tartu University: Erdmann Heinrich Gottlob Artzt, Alexander Nicolaus Scherer, and David Hieronymus Grindel [6, 7]. In his letter to Tartu from 23 November 1822 Ewers reported to the Curator of Tartu University that the possible candidate was private docent G. W. Osann . After some hesitation Osann accepted the professorship of general chemistry and pharmacy at Tartu University.
[FIGURE 1 OMITTED]
The reasons of his hesitation were the unknown living conditions in Tartu and his private life. Young Osann was in love with Adele Schopenhauer (1797-1849), the sister of the philosopher Arthur Schopenhauer, but his love was not returned and so he uneagerly left Germany. A written proof of this is the following fragment from the letter of his mother to his brother Friedrich:
An mich wiederholt er abermals die Abneigung, nach Dorpat zu gehen, und warum? Weil es ihm unangenehm ware, das er ohne Frau kame, da er das so gesagt habe, und da wolle er nach Jena gehen.  (5)
Despite the refused proposal of marriage, in 1823 he travelled to Tartu. Forseeing what would happen later, on 26 November 1826 he married Katharina Christine Stolz, a daughter of a landlord in Schwarzburg-Sondershausen in Germany. The marriage was harmonious and they had four sons, Friedrich, Hermann, Wilhelm, and August, and the daughter Julia .
PEDAGOGICAL AND SCIENTIFIC WORK OF G. W. OSANN IN TARTU (1823-1828)
The investigations of platinum metals
Osann started in Tartu successfully. In 1824 he published the second edition of his book Beitrage zur Chemie und Physik in Jena . In the same year his portrait was painted by the Baltic German painter Carl (Johann Karl Emanuel) Ungern-Sternberg and litographed (Fig. 2). In 1825 he published in Tartu Messkunst der chemischen Elemente, whose second edition was published in Jena in 1830 . In 1827 the first volume of his Handbuch der theoretischen Chemie  appeared. His scientific interests concentrated on platinum ores. In 1819 large deposits of platinum ores were discovered in the Ural Mountains in Russia. The Imperial Government decreed that all mines in the Urals should submit any samples of platinum-bearing ore to St. Petersburg for analysis and in 1825 a government monopoly on the metal was declared.
This discovery made the problem of the separation of platinum from the other platinum metals topical not only in Europe but also in Russia. Difficulties were caused by the great amount of residue left by platinum separation. The Finance Minister, Count Egor Kankrin (1775-1845), became worried about the possible loss of platinum in the residue and sent samples of native platinum to eminent persons and institutions both at home and abroad. One of the participants in the research was J. J. Berzelius (6) in Sweden, who analysed the raw platinum in the classical way and determined the content of platinum and the other known platinum metals .
[FIGURE 2 OMITTED]
Osann decided to visit Berzelius during the summer vacation and he asked in his letter of 22 April 1825 from the University Government permission to travel to Sweden:
Schon langst war es mir wunsch ein Sommerferien zu einer Reise nach Stockholm zu machen, um mich mit dem ausgezeichnesten jetzt lebenden Chemiker J. Berzelius uber mancherlei gegenstande der Wissenschafts zu berathen, meine eigenen Arbeiten hierdurch zu fordern und um so wirksamer und thatig auf hiesiger Universitat zu werden.  (7)
He travelled to Sweden in spring 1826 and Berzelius wrote to F. Wohler on 25 April that Osann was already in Stockholm . Osann asked in his letter of 9 May 1826  the University Government to give him some more time for his vacation. This letter reveals that he had health problems and that he tried to heal himself in a Swedish spa. He promised to return at the beginning of the next semester. Berzelius, who was known by his biting remarks, wrote to the German chemist Friedrich Wohler (1800-1882) about Osann:
Osann ist nicht beneidenswert. Der arme Mann ist so schrecklich hypochondrisch, dass er fruher oder spater vollkommen melancholisch wird. Er sollte bei Mosander Wasser trinken und wurde richtig verruckt; sobald er sich etwas besser befand, reiste er flugs nach Hause.--Er ist ein gutmutiger Mensch, aber ein Chemiker wird er wahrscheinlich niemals, denn er kann nie das, was moglich, von dem, was zu erforschen unmoglich ist, unterscheiden und halt sich stets vorzugsweise an das Unmogliche, indem er sich Subtilitaten verwickelt.  (8)
Osann met Berzelius once more when Berzelius visited him in Wurzburg in 1845. In spite of Berzelius' prognosis Osann started immediately after his return to Tartu analysis of native platinum. On 16 September 1826 Tartu University received a letter from the Finance Minister Kankrin asking that somebody was sent to St. Petersburg to get the "gold crystals" (platinum was called white gold, H.H.) designated for chemical analysis. Osann mentioned in his paper in 1827  that Tartu University obtained four pounds (Russian) of platinum ore used in St. Petersburg to make coins. In that paper Osann described the mineralogical analysis of the ore and treatment with a mixture of nitric and hydrochloric acids. A thorougher review of the analysis of crude platinum is given in his two papers published in Poggendorff's Annalen in 1828 [17, 18].
In the Ural Mountains osmium-iridium ore was first found in 1819 and at the beginning of the 1820s a very rich deposit of platinum ore was discovered in Nizhni Tagil, central part of the Urals. The centre of the investigation of platinum metals in the Russian Empire was the united laboratory of the Mining Department and the Mining Cadets Corps (later institute) in St. Petersburg. The leading role in these investigations was played by the mining engineers Vassili Lyubarskij (1795-1852) and Petr Sobolevskij (1789-1841), whose method for the separation of platinum from ore was introduced into practice in 1827-1828. This method (9) was used to produce the metal for coins .
Analysis of ore from Nizhni-Tagil 
Beginning the analysis with 1.305 g of ore Osann used the well-known in Europe scheme by which the platinum metals were dissolved by treatment with a mixture of nitric and hydrochloric acids. The indissoluble residue (0.0235 g) was left aside and the solution was analysed. The course of the analysis is shown in Scheme 1.
The composition of the ore (Fig. 3) received by Osann and calculated in % by H.H. was: 83.06% Pt, 10.80% Fe, 1.92% Ir, 1.30% Cu, 0.59% Rh, 0.27% Pd, and 1.80% indissoluble residue . The loss at analysis was 0.26%. For detailed analysis of indissoluble residue more primary matter was needed. Osann ordered from St. Petersburg a new portion of crude platinum and used 100 g of it for the next course of analysis paying greatest attention to the indissoluble residue.
Analysis of residue indissoluble in acids 
After treatment of crude platinum with nitric and hydrochloric acids the indissoluble residue was separated. The residue was treated by potassium hydroxide solution, dried, three crystals of potassium nitrate were added, and then melted. Some water was added to the cooled melt and after the partial dissolution of the melt, nitric acid was added. A black precipitate was formed and the mixture had an unpleasant smell. According to Osann, that smell indicated the presence of osmium in the mixture. The mixture was distilled in a retort to evaporate the gaseous osmium oxide (Os[O.sub.4], H.H.). The distillation was interrupted when half of the mixture was left, and the remainder was cooled. After 24 h Osann discovered there long prismatic white slightly pink crystals with a specific lustre. The crystals dissolved when water was added to the distillation residue, but formed again after the residue was warmed and cooled. Osann made three tests with crystals and found that (1) the crystals partly sublimated at heating with blowpipe on charcoal, (2) from the solution in hydrochloric acid a dark grey layer was formed on a zinc stick, (3) the heating test in a glass pipe with both ends fused showed that the crystals in the one end of the pipe vaporized (sublimized) fully forming in the other end of the pipe small lustering needles. Osann was convinced that no known substance behaved similarly. He excluded osmium because the substance did not smell and distil as a liquid. It did not resemble oxides of bismuth, tellurium, or antimony either. (10)
[FIGURE 3 OMITTED]
Osann had used for the analysis 0.1 g of the produced crystals and decided that it would be most reasonable to send the left 0.3 g to Berzelius. In the same paper where Osann describes the analysis  he presents also the answer from Berzelius:
Stockholm d. 10. April 1828. Soviel ich daraus ersehen kann, haben Sie darin einen neuen Stoff gefunden. Denn ich kann aus den kleinen sublimirbaren Krystallen nichts Bekanntes bekommen. (11)
Berzelius had made with the crystals the test with ammonium sulphide and had a precipitate of easily melting grey sulphide turning transparent and yellowish red at heating. At cooling the substance changed again grey and nontransparent. He made also a sublimation test with the crystals.
Repetition of the analysis of residue 
After Berzelius had confirmed the presence of an unknown element, Osann ordered again 100 g of the same kind of platinum from St. Petersburg and repeated the analysis applying the same method as earlier. Yet after the treatment with nitric acid only a very small amount of crystals similar to those received in the earlier analysis were found. The amount of crystals was too small to identify them. However, Osann made here an essential conclusion, supposing that if the new substance formed a volatile oxide like osmium did, it could go over into the distillate together with osmium. (12)
The distillate received by Osann smelled like an osmium compound and it turned dark blue at the addition of gallnut tincture. At saturation with sodium chloride an osmium salt of gallic acid (13) precipitated. The precipitate was filtered and ammonium sulphide was added to the filtrate. By that a small amount of grey precipitate formed, which could be a sulphide of a new metal. These tests convinced Osann that a new metal was present. He named the metal ruthenium, obviously in honour of Russia after its medieval Latin name. At the end of his paper  he mentioned that there was another element in a larger amount present, and that he intended to name it pluran:
Dieses Wort ist zusammengesezt aus den Anfangsbuchstaben des Platins und der Urals. (14)
Detailed analysis of platinum residue
In 1828 Osann published also another paper in Poggendorff's Annalen , where he discussed the analysis of the residue of the treatment of crude platinum by acids in detail. Osann modified only a few details in the preliminary course of analysis. However, the changes made caused essential changes in the results. The description of the whole qualitative analysis is very capacious and it is convenient to follow its course in Scheme 2. In the scheme only the operations that were repeated many times one after another, caused by the occurrence of after-precipitation, are omitted. For clarity the scheme is divided into seven steps.
Step I. First the platinum residue was mixed with potassium hydroxide and heated in the presence of potassium nitrate as oxidant. The melt was digested by water and the alkaline sample was distilled in the retort until a dry residue formed. (In the first analysis the alkaline solution was acidified before distillation.)
Step II. Great attention was paid to the analysis of the distillate from Step I. Ethyl alcohol was added to the distillate as reductant, and a black precipitate formed. The precipitate was filtered and melted with potassium hydroxide. Nitric acid was added to the melt and the acidified sample was distilled. Osann expected that pink crystals would form in the distillation residue as had happened in his first analysis but could not find them. He concluded that if the new element had formed a volatile compound (as he had stated already earlier) it had gone to the distillate. He made with the distillate the tests known for osmium and had positive results. (Actually ruthenium has very similar reactions: it colours the solution with tannic acid bluish green and reduces with ethyl alcohol as well as with zinc forming a black precipitate. H.H.)
Step III. The alkaline distillation residue was evaporated to dry, and a mixture of white and black precipitate formed. At hot filtration the white precipitate dissolved and the black precipitate remained on the filter. When the filtrate was cooled a white precipitate formed again. Osann was convinced that it was a compound of a new element. Here Osann was mistaken. He made numerous chemical and blow-pipe tests with the white oxide with a grey tint and could not detect any known element. He tried to reduce the oxide to metal and obtained a tiny gold-yellow grain. He wrote [18, p. 339]:
Da dieses Metall, welches ich nach den so eben beschriebenen Eigenschaften als ein neues glaube annehmen zu mussen, sich in grosserer Menge als das fruher erwahnte in dem uralschen Platin befindet, und auch durch seinen schonen, dem Golde ahnlichen metallischen Glanz sich mehr empfiehlt, so glaube ich, das der Vorschlag, das zuerst aufgefundene neue Metall Ruthenium zu nehmen, besser auf dieses angewendet werden konnen. (15)
In a later paper, published in 1829 , he confessed that the white precipitate was mainly silicium oxide, which precipitated from the solution at the repetition of the acid-alkali treatment and he eliminated the presence of a new metal in the white precipitate.
Step IV. The black precipitate received in Step III was added to the combined hydrochloric filtrates and the mixture was saturated with gaseous hydrochloride. The black precipitate was now separated by filtration.
Step V. The black precipitate was treated alternately with alkali and acids and finally platinum and silicious oxide were detected.
Steps VI and VII. In combined hydrochloric filtrates Osann detected several metals: Ir, Fe, Cu, Rh, Fe-Rh, Fe-Ru, and Ir or a questionable new element polin. Prof. Carl Claus (16), who analysed the platinum ores about 20 years later in Kazan University, Russia , was of the opinion that Osann could not have discovered ruthenium because he had not examined the hydrochloric filtrates carefully enough. In his latest paper about platinum analysis Osann refuted Claus's accusation referring to steps VI and VII of the scheme. He wrote in his paper in Poggendorff's Annalen 1845 :
Wenn der Hr. Prof. Claus angiebt, es sey mir die Entdeckung des Rutheniums entgangen, weil ich die salzsauren Auszuge des weissen Oxyds nicht untersucht hatte, so irrt er sich. In meiner Abhandlung uber den Platinruckstand, welche in den Annalen von Poggendorff, Bd. 14 (1828) abgedruckt ist, wird er die Untersuchung der salzsauren Auszugen S. 349 bis 352 finden. (17)
In step VI gaseous chlorine as oxidant was passed through the combined hydrochloric filtrates. As a result, the solution coloured red, and a black precipitate formed. In that precipitate iridium was found. In the washing water of the precipitate whitish yellow silver chloride fell down and was filtered. Silver evidently came from the silver crucible used for melting the sample with potassium hydroxide and nitrate. After the filtration of the silver chloride the hydrochloric filtrates were alkalized with soda. After some days (Step VII) a grey precipitate with a black surface appeared. The precipitate was dried and digested with hydrochloric acid. A small amount of a black powder was left, filtered, and reduced to metal, which was evidently rhodium.
The hydrochloric filtrate was alkalized with soda. A black precipitate, which evidently belonged to rhodium and iron, formed. The alkaline filtrate was acidified with hydrochloric acid. In the solution whitish yellow flakes formed. The precipitate was filtered and dried. The dry residue had a reddish brown colour and was identified as a compound of ruthenium and iron. The acidic filtrate was neutralized with soda and a brownish grey precipitate of iron and copper compounds was formed. To identify the precipitate it was filtered and dissolved in hydrochloric acid. Ammonia was added to the solution, and iron precipitated as oxihydroxide. Copper stayed in the solution forming a blue complex with ammonia. The alkaline filtrate received by filtration of iron and copper compounds was evaporated to dry. A grey residue that reminded sponged platinum formed. Osann made eleven different tests but did not get a clear enough answer about the character of the grey powder. Osann declared:
Obwohl nun dieses Metall sich durch seine Aufloslichkeit in Sauren, so wie durch die Eigenschaft, keinen orangefarbenen Platinsalmiak zu geben, wesentlich vom Iridium unterscheidet (18) so bin ich doch der Meinung, berucksichtigend das Mangelhaft unserer Kenntnisse der Eigenschaften des Iridiums, mit dem Ausspruch der Neuheite dieses Metall, zuruckhalten, bis unsere Kenntnisse uber diesen Gegenstand eine grossere Erweiterung werden erlangt haben. Sollte sich der aufgefundene Unterschied bewahren, so schlage ich den Name Polin vor (von [TEXT NOT REPRODUCIBLE IN ASCII.] grau). Bis dahin nehme ich es einstweilen als Iridium an.  (19)
Osann could now summarize the elemental composition of the platinum residue as follows: osmium, ruthenium, silica, iridium, iron, platinum, copper, and traces of rhodium. He calculated an approximate quantitative relationship of the constituents: osmium, ruthenium, and iridium each made up 25% and the remaining 25% consisted of the other elements.
Complementary analysis of the part of platinum ore dissoluble in acids
Osann made a complementary analysis  for the part of platinum ore dissoluble in nitric and hydrochloric acids mainly to check the content of rhodium. After the evaporation of the excessive acid in solution, palladium dicyanide was precipitated. The difference from the earlier analysis  was that the filtrate was saturated with soda instead of ammonium chloride (Scheme 1). At saturation a dark brown precipitate was formed. The sublimation test of the precipitate in a glass tube gave two sublimates. The one formed first was taken from the glass tube together with the residue of soda and sublimized again in another glass tube. That sublimate proved to be mercury. The second sublimate (0.0012 g) was dissolved in hydrochloric acid. The solution was saturated with ammonia, and when sulphide ammonia was added a greyish brown precipitate formed. Based on these two properties--sublimation and formation of an insoluble sulphide--Osann concluded that he had here the "new" element mentioned already earlier and named pluran.
The final results of the analysis of platinum ore received by Osann were: the part soluble in acids: Pt 80.87%, Fe 10.92%, Rh 4.44%, Cu 2.30%, Pd 1.301%, pluran 0.06%, and traces of S, Ti, and Os; the insoluble part (0.113%): Os, Ru, and Ir 0.081%; silica, Fe, Pt, Cu, and traces of Rh 0.027% (the missing 0.005% is evidently a mistake caused by the rounding of numbers, H.H.) .
G. W. OSANN LEAVES TARTU AND SETTLES IN WURZBURG
Looking back at the years Osann spent in Tartu it seems that he was there unwillingly, waiting for an opportunity to return to Germany. His letter to J. B. Trommsdorff (20) in 1825  reveals that Osann planned to establish in Germany a factory to produce tartaric acid and potassium hydroxide from the potassium tartrate forming in the wine industry. He wrote that he had no expectations for a sufficient heritage and so he hoped that that idea could provide a source of an additional income in the future and asked for advice. His project was never realized as we know and his career remained academic.
In 1828 Osann was invited to Wurzburg University to become professor of physics and chemistry. In his letter of 12 March 1828 to the Council of Tartu University he asked to relieve him of his post at the University in connection with his moving to Wurzburg . The same day Osann wrote to the apothecary Burchard in Reval21 that he was leaving Estonia and asked him to give his best greetings to his friends in Reval:
Meinen Freunden in Reval, gibt es andere dergleichen ... Reval mit seinen schicken Umgabungen werde ich daher nicht wieder sehen.  (22)
Osann had a good reputation as a productive writer of textbooks and he was known, with some reservations, as the discoverer of a new platinum element--ruthenium. Some confusion about that fact was caused by his hurriedly made announcement of the discovery of two other elements--pluran and polin. In 1829 he answered in Poggendorff's Annalen  to the letter published by Prof. Berzelius, who was suspicious about the occurrence of a new element in the white oxide received by Osann in the analysis of the platinum residue. Osann agreed with Berzelius that the white oxide he received in the analysis of platinum residue was really a combined precipitate of titanium acid, zirconium oxide, and silica and not a new element. In 1841-1842 Prof. Carl Claus at Kazan University in Russia began to research the platinum metals and after successful separation of pure ruthenium in 1844 identified its properties. Claus was everywhere noted as the discoverer of ruthenium. However, he used the name given by Osann--ruthenium. Osann wrote in his paper in 1845  that it was excellent for science if the same discovery had proof by two scientists. Osann himself repeated in Wurzburg the analysis of platinum residue received from St. Petersburg, but received nothing new.
Osann began an effective work in educational and scientific fields. His attention was attracted increasingly more by problems of physics such as electrical phenomena, electromagnetism, electroinduction, and light phenomena. He published nearly 50 papers (see for examples Fig. 4), mostly in K. W. G. Kastner's journal Archiv fur die gesammte Naturlehre and O. L. Erdmann's Journal fur technische und okonomische Chemie [28, 29].
Some papers from the Wurzburg period  are given as examples:
1843-1846 "Neue Beitrage zur Chemie und Physik"
1836 "Analyse des Mineralwassers vom Ludwigs-Brunnen zu GrossKarben in der Wetterau... in Oberhessen"
1847 "Grundzuge der Lehre von dem Magnetismus und der Elektricitat" (Fig. 4)
1849 "Programm uber die Bedeutung der Naturlehre unter den allgemeinen Wissenschaften"
1849 "Darlegung mehrere neuer Versuche uber Gassaulen und das Ozon"
1852 "Erfahrungen in dem Gebiete des Galvanismus gesammelt. Fur Physiker, Chemiker und Techniker"
[FIGURE 4 OMITTED]
[FIGURE 5 OMITTED]
Osann took actively part in the academic life. He belonged as a foundation member to the society Physikalisch-medizinischen Gesellschaft zu Wurzburg, was Royal Bavarian privy councillor, corresponding member of Munich Academy of Science, and member of many other societies. In 1840/41 Osann was elected dean and in 1848/49, rector of Wurzburg University (Fig. 5). The subject of his promotion speech was the significance of the natural studies among the sciences. He said:
Die Kunst Beobachtungen zu verstehen, macht den Naturforscher. Es gehort Kenntnis und Urtheil dazu, in einer Beobachtung das heraus zu finden[!], was bekannt und was neu ist. Mitunter waren es ganz geringfugige von Vielen ubersehene Umstande, welche zu den grossten Entdeckungen gefuhrt haben.  (23)
The last paper by Osann was published in the journal Wurzburger Naturwissenschaftliche Zeitschrift in 1866. It was about the thunderclap into the tower of a church in Wurzburg on 6 January 1865 .
Gottfried Wilhelm Osann died in Wurzburg on 10 August 1866 [1, 8].
The question about the priority of the discovery of ruthenium can be answered only on the ground of a thorough study of the analysis and conclusions made by Osann using the modern knowledge about the chemistry of ruthenium.
Following Osann's analysis we must agree that the properties of the new element described by him belong to ruthenium: mineral acids do not affect the metal and it is dissolved by alkaline oxidizing fusion (Scheme 2, Step I). As a result ruthenium forms soluble ruthenate (VII, VI)-ions, staying in distillation residue (Step III) and/or forms volatile ruthenium (VIII) tetroxide Ru[O.sub.4], which is detected in the distillate (Step II). Tetroxide is usually reduced by hydroxide ion and it forms ruthenate ions. It is easily reduced also by ethyl alcohol forming oxides such as black ruthenium sesquioxide [Ru.sub.2][O.sub.3] or brownish black dioxide Ru[O.sub.2]. Hydrous oxides are commonly precipitated in alkaline solution. When freshly precipitated, they may be soluble in acids, but after aging only with great difficulty or not at all (Steps IV-VII) .
It must also be taken into consideration that Carl Claus left the name of the element given by Osann--ruthenium--unchanged. Thus he indirectly recognized the rights of Osann to the discovery.
We must remember that after analysing the pink crystals received by Osann Berzelius declared that nothing already known could be found and consequently the crystals had to belong to a new element.
The trouble of Osann was that he could not repeat his results and was not sure in his conclusions. As Berzelius said--he involved himself in details. The "discovery" of two other elements, polin and pluran, caused misunderstanding and overshadowed the discovery of ruthenium. Osann had serious difficulties to analyse the too small quantities of samples for the determination of the element accounting for 1-2%. It was not always possible to make enough tests with the received compounds.
Claus analysed platinum residue 16 years later. He had at his disposal enough substance and the experiences of Osann. Prof. Carl Claus had worked in the same laboratory where Osann had worked earlier. Claus has the honour of isolating ruthenium as a pure element and determining the properties of the new element. Concluding finally all the for and against arguments we can attribute the priority of the discovery of ruthenium to G. W. Osann.
Received 6 January 2004
[1.] Pluckhan, A. Transkription und Kommentierung der Briefe von Gottfried Wilhelm Osann (1797-1866) und Emil Osann (1787-1842) an Johann Bartholomaus Trommsdorff (1770-1837): Brief von Amalie von Voigt/Weimar an Friedrich Osann--vom 8. Mai (1826?). Diploma paper, Ernst-Moritz-Arndt-Universitat, Greifswald, 1998.
[2.] Allgemeine Deutsche Biographie, Vol. 24. Dunckler & Humblot, Leipzig, 1887.
[3.] Osann, G. W. Rede zur Feier des 18. Junius: auf dem Turnplatze zu Erlangen gehalten. Erlangen, 1819.
[4.] Chemnitius, F. Die Chemie in Jena von Rolfink bis Knorr (1629-1921). Jena, 1929.
[5.] Osann, G. Beitrage zur Chemie und Physik. Jena, 1822-1824.
[6.] Siilivask, K. (Comp.) Tartu ulikooli ajalugu, II, 1798-1918. Eesti Raamat, Tallinn, 1982.
[7.] Hodrejarv, H. History of analytical chemistry in Estonia (1800-1950). Fresenius J. Anal. Chem., 1997, 357, 191-196.
[8.] Letter of G. Ewers to the Curator of Tartu University 23. Nov. 1822. EAA, f 402, n 3, s 1237, 3.
[9.] Osann, G. W. Messkunst der chemischen Elemente. Dorpat, 1825; 2nd edn., Jena, 1830.
[10.] Osann, G. W. Handbuch der theoretischen Chemie, Vol. I. Dorpat, 1827.
[11.] Griffith, W. P. Spurious platinum metals. Chem. Brit., 1968, 4, 430-434.
[12.] Letter of G. Osann to the Council of Tartu University, 22 April 1825. EAA, f 402, n 3, s 1237, 29.
[13.] Holmberg, A. Bibliographie de J. J. Berzelius. Stockholm, 1953.
[14.] Letter of G. Osann to Tartu University, 9 May 1826. EAA, f 402, n 3, s 1237, 65.
[15.] Wallach, O. Briefwechsel zwischen J. Berzelius und F. Wohler. Leipzig, 1901.
[16.] Osann, G. Analyse des Platins vom Ural. Poggendorff's Annalen der Physik und Chemie, 1827, XI (87), 311-322.
[17.] Osann, G. Fortsetzung der Untersuchung des Platins vom Ural. Poggendorff's Annalen der Physik und Chemie, 1828, XIII (89), 283-297.
[18.] Osann, G. Fortsetzung der Untersuchung des Platins vom Ural. Poggendorff's Annalen der Physik und Chemie, 1828, XIV (90), 329-357.
[19.] Kljuchevich, A. S. Carl Carlovich Claus. Izd. Kazanskogo universiteta, 1972.
[20.] Nikol'skij, B. P. & Il'enko, E. I. Investigation of the hydrolysis of nitrate complexes of nitroruthenium. Radiokhimiya, 1966, 8, 2.
[21.] Osann, G. Berichtigung, meine Analyse des uralschen Platins betreffend. Poggendorff's Annalen der Physik und Chemie, 1829, XV (91), 158.
[22.] Claus, C. Uber die Platinruckstand. Bull. Acad. Sci. St. Petersb., 1844, 3, 37-48; Fortsetzung der Untersuchung des Platinruckstandes nebst vorlaufiger Ankundung eines neuen Metalls. Bull. Acad. Sci. St. Petersb., 1844, 3, 353-371.
[23.] Osann, G. Analyse des in Salpeter-Salzsaure unaufloslichen Ruckstands des uralschen Platins (neue Bearbeitung). Poggendorff's Annalen der Physik und Chemie, 1845, 64 (140), 197-208.
[24.] Letter of Gottfried Wilhelm Osann/Dorpat an Trommsdorff, 12 January 1825. Staatsbibliothek zu Berlin, Preussischer Kulturbesitz, Handschriftenabteilung, Nachlass 259 J. B. Trommsdorff und Nachf. 19, Nr. 696-717.
[25.] Trommsdorff, J. B. (Comp.) Taschenbuch fur Chemiker und Apotheker, Vol. 46. Weimar, 1825.
[26.] Letter of G. Osann to the Council of Tartu University of 12 March 1828. EAA, f 402, n 3, s 1237, 62.
[27.] Letter of G. Osann to J. Burchard. Estonian History Museum, "D" fond, f 54, n 1.
[28.] J. C. Poggendorff's Biographisch-literarisches Handworterbuch zur Geschichte der exacten Wissenschaften, Vol. II. Leipzig, 1863; Vol. III, Part II, Leipzig, 1898.
[29.] Levitskij, G. V. Biographical Glossary of Professors and Teachers of the Imperial Yur'ev, Formerly Derpt University, Vol. 1. Yurjev (Tartu), 1902.
[30.] Bibliotheks Verbundes Bayern-Kurzanzeige. Datenbank: Bibliotheks Verbund Bayern Treffer 1-17. http://www-opac.bib-bvb.de/
[31.] Rede zur Antritte des Rectorats von Dr. G. W. Osann gehalten am 2. Januar 1849 in der Universitats-Aula. Wurzburg, 1849.
[32.] Osann, G. Ueber den Blitzschlag, welcher am 6. Jan. 1865 den Thurm der Neubaukirche in Wurzburg traf. Wurzburger Naturwissenschaftliche Zeitung, 1866/1867, 6, 38-42.
[33.] Cotton, F. A., Wilkinson, G., Murillo, C. A. & Bochmann, M. Advanced Inorganic Chemistry. John Wiley & Sons, New York etc., 1999.
Tallinn Pedagogical University, Narva mnt. 25, 10120 Tallinn, Estonia
(1) Now the University of Tartu, Estonia. In the 19th century it was a Baltic German university in the Russian Empire.
(2) Ernst Gottfried Fischer (1754-1831) was professor of physics at Berlin University from 1810.
(3) Johann Wolfgang Dobereiner (1780-1849) was professor of the philosophical faculty at Jena University in 1810-1849.
(4) Platinum was first mentioned in Europe at the end of the 17th century by a Bohemian Jesuit, who described the metal as white gold. In 1751 the Swedish scientist Scheffer categorized platinum as a precious metal as it dissolves only in aqua regia.
(5) Translation: He had mentioned me time and again his unwillingness to go to Dorpat and why? That it was unpleasant for him to go without a wife he had already stated, and therefore he will go to Jena.
(6) Jons Jacob Berzelius (1779-1848), professor of chemistry at Karolinska Institutet in Stockholm, honorary doctor of Tartu University from 1827. He had high reputation in the whole of Europe and several well-known chemists used the opportunity to work in his laboratory: F. Wohler, G. Rose, G. Magnus, and others.
(7) Translation: For a long time I have had a wish to travel in my vacation to Stockholm to discuss with one of the most outstanding among the now-living chemists J. Berzelius several scientific problems concerning my own work to advance that and to be more useful and active to the university here.
(8) Translation: We cannot envy Osann. The poor man is so awfully hypocondric that sooner or later he will be melancholic. He had drunk water by Mosander [in a spa, H.H.] and got really mad; as soon as he felt himself a little better he hurried home.--He is a good-natured man, but he will most likely never become a chemist. He cannot separate that what is worth to investigate from that what is unworth. He prefers rather the unworthy and involves himself in small details.
(9) The ore was treated with aqua regia, the indissoluble part was filtered, and platinum was precipitated from the received solution as chlorocomplex of ammonia. By thermal decomposition of the precipitate platinum formed a porous spongy mass. Pressing the sponge yielded a well malleable platinum. The method used in Europe was introduced by Wollaston and was kept secret for a long time but did not differ very much from the Russian method used in St. Petersburg.
(10) It was later found that ruthenium solution when treated with nitric acid forms by hydrolysis several hydroxocomplexes with a coordinated NO group, which are indissoluble in the region of pH 2-9 .
(11) Translation: As much as I can understand you have found a new substance and I cannot detect in the little crystals, which are able to sublimate, any familiar [substance].
(12) Ru[O.sub.4] is volatile but needs for forming a stronger oxydant than Os[O.sub.4] does; its boiling point is lower, H.H.
(13) Gallussaure osmiumoxide by Osann, H.H.
(14) Translation: That word is put together of the initial letters of platinum and Urals.
(15) Translation: As the metal that by tests seems to be a new element occurs in a bigger amount in platinum from the Ural than the earlier one, and also has a golden metallic lustre, I think that the name ruthenium that was used for the metal found earlier fits better for the element found later.
(16) Carl Claus (1796-1864) was born in Tartu to a Baltic German family. He was educated and started to work at Tartu University. He worked also at Kazan University and later until his death again at Tartu University.
(17) Translation: If Mr. Prof. Claus refers that I have missed the discovery of ruthenium as I have not investigated the hydrochloric extract of the white oxyde, he deceives himself. In my treatment of the platinum residue, printed in Poggendorff's Annalen, Vol. 14 (1828), he can find the investigation of hydrochloric extract from p. 349 to p. 352.
(18) Osann used a test where in the presence of iridium the nitric and hydrochloric acid solution of platinum coloured orange when ammonium chloride was added. H.H.
(19) Translation: Although this metal substantially differs from iridium by its solubility in acids as well as by the property not to form any orange-coloured compound of platinum and [ammonia.sup.18] I am still of the opinion that looking back at our deficient knowledge about the properties of iridium, we must restrain from declaring the novelty of that metal until our knowledge in that field extends. But, if the determined differences are valid, I propose the name polin ([TEXT NOT REPRODUCIBLE IN ASCII.], grey). Until then I will regard it temporarily as iridium.
(20) Johann Bartholomaus Trommsdorff (1770-1837) is founder of scientific pharmacy. He published a critical review about Osann's book Beitrage zur Chemie und Physik  in the Taschen-Buch fur Chemiker und Apotheker  in 1825. He approved Osann's text-book and said that he was a sharp-sighted naturalist and a good experimentator.
(21) Now Tallinn, the capital of Estonia.
(22) Translation: My friends in Reval, does anywhere exist any similar ... Reval with its marvellous surroundings that I can never see again.
(23) Translation: The art to understand the observations will make the naturalist. For that we need the knowledge and ability to distinguish between what is new and what is already known. Sometimes there are absolutely insignificant details among the facts of the case that will lead to the great discovery.