Carl Wilhelm Hahn

Dr. Carl Wilhelm Hahn (lat. Carolus Guilielmus Hahn) (* December 16, 1786 - † November 7, 1835) was a German zoologist and author of the first German monograph on spiders. C. W. Hahn was an all-round natural scientist - not at all unusual for his time. Surprisingly he seems to have been almost forgotten. Even the few biographical dates^[2][3][4], which have been published in secondary literature are not always correct as clarified by P. Sacher in his "attempt at a Biography"^[5]:

C. W. Hahn's signature from 1819 ^[1]

Life and lifework

Carl Wilhelm Christian Hahn was born in Weingartsgreuth, Upper Franconia as the first son of Johann Michael Hahn (1734-1824), who was court and palace gardener on the estate of Baron von [?S]eckendorff, later palace gardener for Count Friedrich von Pückler. C. W. Hahn obeyed the general call to arms as early as 1813. He served as a quarter master and in 1816 received "honourable discharge"^[6]. Afterwards he lived with his parents in Fürth and, according to Hahn, made up his mind to devote his life to his predilection for natural history, an interest he had had since early childhood and which intensified during his studies in Erlangen. He commenced work on his first ornithological work "Birds from Asia, Africa, America and New Holland". When his "often promised and well earned position"^[7] failed to materialize, Hahn undertook what was for that time, in his field, a very unusual step and went freelance. From then on he called himself a natural historian and occasionally also a scholar. On 24^th February 1820, having in the meantime qualified as a Dr. Phil. at the University of Erlangen, he married Victoria Francisca Kaltdorff, née Schaefer. His wife, the widow of a doctor of medicine, was about five years older than he, and had three children by her previous marriage. She was at this time without means, but was expecting quite large inheritance from her maternal uncle before long. Their own child Anna Friedericke was born at the end of 1820 or 1821.

"Lÿcosa Waglerii, mihi" sensu Hahn 1822, Instalment 3, Table 3

It can be assumed, that Hahn was in close contact with the universally known natural scientist Jakob Sturm and probably with his two sons. He named a spider species after Jakob Sturm: "Araneus Sturmii", now "Atea sturmi (Hahn, 1831)" or "Araneus s. (Hahn, 1831)"^[8]. His relationship with Johannes Georg Wagler must have been similarly close. He also named a spider species after him: "Lÿcosa Waglerii", now "Pardosa wagleri (Hahn, 1822)"^[9]. Nothing reliable is known about other contacts with the remarkably productive Nuremberg zoologist scene. Nor there is any proof, that Hahn knew Franz von Paula (von) Schrank personally, a highly regarded natural scientist, to whom he dedicated the "Monograph on Spiders". The scientific value of Hahn's lifework in natural history varies. His ornithological work, for example, never had any discernible influence on this field. On the other hand Hahn's work on bugs (Heteroptera) is just as important as his works on spiders (Araneae). One species of bug even carries his name: "Lopus hahni Stål, 1860". He was also given this honour in the field of arachnology: Carl Ludwig Koch, who continued "The Arachnids" after Hahn's death, called a genus after him in 1841 ("Hahnia"), on which later the name of the whole family was based - "Hahniidae Bertkau, 1878". According to L. Gebhardt^[10] Hahn died in Nuremberg on 7^th November 1835, "of a lung complaint in the prime of life".

Monograph on Spiders

About the rarity of the work: today only about 14 – partially incomplete – copies are known. They were recorded and examined by Sacher^[11] from Germany (Wittenberg, Berlin, Jena, Darmstadt, Erlangen, Kiel, Munich, Frankfurt/M.), England (London), U.S.A. (Cambridge/Mass.), Austria (Vienna) and France (Paris). "Monograph on Spiders" has become a rarity already at the beginning of the 20^th century.^[12] This rarity can be explained by the fact that only small editions were produced: "More than a hundred copies of each instalment will not produced", remarked Hahn on this subject in 1820. The great rarity of complete copies probably results primarily from the long gap between instalments. It has not been possible to ascertain whether Hahn broke with his publisher or Lechner with him. However a separation took place some time before the publication of the sixth instalment. Indeed in 1831 the first instalment of "The Arachnids" had already appeared in Zeh's Bookshop in Nuremberg as an obvious substitute for the "Monograph on Spiders". It was more accessible and thus also better known than the "Monograph on Spiders". In the sixth instalment of the "Monograph on Spiders" the publisher Lechner 1831 inserted a small format "message", which announced that Hahn had been relieved as editor. Probably the contents of the sixth instalment still can be wholly attributed to Hahn, even though he had only admitted to the first five instalments. For obvious reasons the publisher Lechner was not in a position to print anything new, even though he still had original drawings in his possession, which he published without Hahn's consent. For this reason alone it was already impossible to compete with Hahn's new project. It was therefore not surprising that the promised ninth instalment failed to appear. In the past there has been some confusion regarding the year of publication, particularly of the instalments 2, 5 and 7.^{[13][14][15][16][17][18]} Probably this confusion has been caused both by the partial absence of dated forewords and of dust jackets for the individual instalments, as by the fact, that the bookshop and later (1822) publisher Lechner did not only provide instalments which were sold later with a non-original cover, but in a good many cases also overwrote the year of publication with the year of sale. On basis of recent investigation^[19] the correlation between instalments and the years of publication has been clarified as follows:

Instalment	1	2	3	4	5	6	7	8
Year of publication	1820	1821	1822	1826	1827	1831	1833	1836

It should be noted that a definitive representative copy of "Monograph on Spiders" probably does not exist (any more). The available copies differ in several features as detailed pointed out by Sacher^[20]. For this reason it was used a combined version for the reprint of 1988.

"Eresus cinnaberinus, Walk." and "Eresus annulatus, mihi" sensu Hahn 1821, instalment 2

But "Monograph On Spiders" is fare more than just a bibliophilic work. Firstly it includes nine still valid first descriptions of spider species. In the 19th century it was not unusual, that a majority of "new species" had been previously described by other authors. This is because in contrast to the modern differentiation of species, the genital structures were not taken into consideration at that time. For that reason smaller differences in the colourings and markings have possibly given rise to different species designations. At any rate a sixth of the forms described by Hahn are still valid today. That Hahn was a good observer and gave exact descriptions is shown clearly by the example of Eresus annulatus (= E. sandaliatus (Martini & Goeze, 1778)) and E. cinnaberinus (= E. niger (Petagna, 1787)). After more than 150 years arachnologists follow his separation of these taxa today again.^{[21][22][23][24]} Secondly its monographic character is remarkable. It is the first monographic work for spiders in German language. Further 180 years ago it was very unusual to use a group like spiders as a sole subject of a book. Apart from a natural history of spiders by the Frenchman Walckenaer in 1806^[25] there had been no work of that time which exclusively had spiders as its subject. Thirdly spider illustrations in the "Monograph on Spiders" show Hahn to be an above average artist and lithographer. Finally "Monograph on Spiders" and "The Arachnids" are different ways of carrying out the same project and they can both be considered as autonomous works, whereas Brignoli^[26] - an important cataloguer in arachnology - regarded "Monograph on Spiders" only as a sort of blueprint for "The Arachnids". The "Monograph on Spiders" can therefore be counted among the early arachnological works that are still scientifically relevant today. As well it is valuable for the history of science. This pioneering achievement should therefore be assumed to have been treated inadequate in the past.

Complete List of Works

(all illustrated by Hahn himself)

• Voegel(,) aus Asien, Africa, America, und Neuholland, in Abbildungen nach der Natur mit Beschreibungen. 19 instalments, Lechner: Nürnberg, 1818-1836.
• Monographia Aranearum - Monographie der Spinnen. 8 instalments, Lechner: Nürnberg, 1820-1836.
• Naturgetreue Abbildungen zur allgemeinnützigen Naturgeschichte der Thiere Bayerns. Author: Nürnberg, 1826-1828.
• (together with J. E. von Reider) Fauna Boica, oder gemeinnützige Naturgeschichte der Thiere Bayerns. Zeh: Nürnberg, 1830-1835.
• Die Arachniden. Getreu nach der Natur abgebildet und beschrieben. 2 volumes, Zeh: Nürnberg, 1831-1834 (from the 3^rd volume onwards continued by C. L. Koch).
• Die wanzenartigen Insecten. Getreu nach der Natur abgebildet und beschrieben. 3 volumes, Zeh: Nürnberg, 1831-1835 (from the 4^th volume onwards continued by G. A. W. Herrich-Schäffer).
• Gründliche Anweisung Krustenthiere, Vielfüße, Asseln, Arachniden und Insecten aller Klassen zu sammeln, zu präpariren, aufzubewahren und zu versenden. Zeh: Nürnberg, 1834.
• Ornithologischer Atlas oder naturgetreue Abbildung und Beschreibung der aussereuropäischen Vögel. 6 instalments, Zeh: Nürnberg 1834-1836 (continued by H. C. Küster).
• Icones Orthopterorum. Abbildungen der hautflügeligen Insecten. 1 instalment, Lechner: Nürnberg, 1835.

About C. W. Hahn

• "This person is indeed extremely foolish, but is incidentally polite, draws exceedingly well, has a beautiful hand, has much knowledge of natural history and botany, and is skilled in stuffing birds. However because of his foolishness he requires strict supervision. His other talents and capabilities make him worthy of some consideration.", Count Pückler in 1805 to colonel of the infantry regiment, Erbach von Henneberg.^[27]

References

^ ^	Bonnet, Pierre: Bibliographia Araneorum. 3 vols. Toulouse, 1945-1961. [Citation taken from P. Sacher, 1988, p. 139]
^	Brignoli, Paolo M.: On the correct dates of publication of the arachnid taxa described in some works by C. W. Hahn and C. L. Koch (Arachnida). Bulletin of the British Arachnological Society, 6, (9), 1985, p. 414-416. [Citation taken from P. Sacher, 1988, p. 141; modified]
^ ^	Gauckler, K.: Goldäugige Springspinne und Zinnoberrote Röhrenspinne in Nordbayern. Mitteilungen der naturhistorischen Gesellschaft Nürnberg, 6, 1971, pp. 51-55. [Citation taken from P. Sacher, 1988, p. 141; modified]
^ ^	Gebhardt, Ludwig: Die Ornithologen Mitteleuropas. Giessen, 1964; additions: J. Orn. 111, Special Edition 1970, p. 164-165 and J. Orn. 115, Special Edition 1974, p. 107. [Citation taken from P. Sacher, 1988, p. 139; modified]
^	Hamberger, G. C. & J. G. D. Meusel: Das gelehrte Teutschland oder Lexikon der jetzt lebenden teutschen Schriftsteller. 5th edition, 23 vols., Lemgo, 1796-1834. [Citation taken from P. Sacher, 1988, p. 139]
^	Junk, W.: Rara Historico-Naturalia. Vol. 2, Pars 1, The Hague: 1926, p. 137. [Citation taken from P. Sacher, 1988, p. 129]
^	Menge, Anton: Preussische Spinnen. Erste Abtheilung. Schriften der Naturforschenden Gesellschaft in Danzig (Neue Serie) 1, 1866, p. 1-152. [Citation taken from P. Sacher, 1988, p. 141; modified]
^ ^ ^	Platnick, Norman I.: The World Spider Catalog. Version 6.0, The American Museum of Natural History, 2000-2005, http://research.amnh.org.
^	Ratschker, Ulrich Martin & Heiko Bellmann: Zur Bestimmung der mitteleuropäischen Arten der Gattung Eresus Walckenaer 1805 (Arachnida: Araneae: Eresidae). Beiträge zur Araneologie, 4, 1995 ("1994"), pp. 217-218.
^	Ratschker, Ulrich Martin & Heiko Bellmann: Untersuchungen zur Taxonomie und Verbreitung von Eresus cinnaberinus (Olivier, 1789) (Araneae, Eresidae). Mitteilungen der Deutschen Gesellschaft für allgemeine und angewandte Entomologie, 9, Gießen, 1995, pp. 807-811.
^	Roewer, Carl Friedrich: Katalog der Araneae von 1758 bis 1940, bzw. 1954. 2 vols., Bremen and Brussels, 1942-1945. [Citation taken from P. Sacher, 1988, p. 139; modified]
^ ^ ^ ^	Sacher, Peter (Ed.): Carl Wilhelm Hahn, Monographie der Spinnen (1820-1836), Mit einem Kommentar in deutsch und englisch, herausgegeben von Peter Sacher. Zentralantiquariat der DDR: Leipzig, 1988, 143 pp (Reprint of: Hahn, Carl Wilhelm, Monographie der Spinnen, 8 instalments, Lechner: Nürnberg, 1820-1836. With a commentary in German and English of Peter Sacher).
^	Thorell, Tord Tamerlan Teodor: Remarks on Synonyms of European Spiders. Uppsala, 1870-1873.[Citation taken from P. Sacher, 1988, p. 141; modified]
^	Walckenaer, Charles Athanase: Tableau des aranéides ou charactères essentiels des tribus, genres, familles et races que renferme le genre Aranea de Linné, avec la désignation des espèces comprises dans chacune de ces divisions. Paris, 1805, 88 pp. [Citation taken from P. Sacher, 1988, p. 141 - eventual mistaken by Sacher for Walckenaer, 1806?; modified]
–	Walckenaer, Charles Athanase: Histoire naturelle des aranéides. Vols. 1-3, Paris - Strassbourg, 1806. [Citation taken from N. I. Platnick, 2000-2005]
^	Walckenaer, Charles Athanase: Histoire naturelle des insectes. Aptères 1. Paris, 1837, p. 1-682. [Citation taken from P. Sacher, 1988, p. 141; modified]
^ ^ ^	Curriculum vitae from 1819, In: residence records of the Nuremberg town archives, shelf mark C 7 NL.2570. [Citation taken from P. Sacher, 1988, p. 139]
^	Pückler archives in the Fürth town archives. [Citation taken from P. Sacher, 1988, p. 139]