Dr. Carl Wilhelm 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, which have been published in secondary literature are not always correct as clarified by P. Sacher in his "attempt at a Biography":
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 Seckendorff, 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 his honourable discharge. 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" 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 February 24, 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.
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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: Araneus Sturmii, now Atea sturmi (Hahn, 1831). His relationship with Johann Georg Wagler
must have been similarly close. He also named a spider species after him: Lÿcosa Waglerii, now Pardosa wagleri (Hahn, 1822). Nothing reliable is known about other contacts within the remarkably productive Nuremberg
zoologist scene. Nor is there 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 the true 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 "Die Arachniden" 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 Hahn died in Nuremberg on November 7, 1835, "of a lung complaint in the prime of life".
Monographie der Spinnen – 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 from Germany (Wittenberg, Berlin, Jena, Darmstadt, Erlangen, Kiel, Munich, Frankfurt/M.), England (London), U.S.A. (Cambridge/Mass.), Austria (Vienna) and France (Paris). "Monographie der Spinnen" has become a rarity already at the beginning of the 20th century. This rarity can be explained by the fact that only small editions were produced: "More than a hundred copies of each installment will not produced", remarked Hahn on this subject in 1820. The great rarity of complete copies probably results primarily from the long gap between installments. 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 installment. Indeed in 1831 the first installment of "Die Arachniden" had already appeared in Zeh
In the past there has been some confusion regarding the year of publication, particularly of the installments 2, 5 and 7. Probably this confusion has been caused both by the partial absence of dated forewords and of dust jackets for the individual installments, as by the fact, that the bookshop and later (1822) publisher Lechner did not only provide installments 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 the correlation between installments and the years of publication has been clarified as follows:
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| Year of publication | 1820 | 1821 | 1822 | 1826 | 1827 | 1831 | 1833 | 1836 |
It should be noted that a definitive representative copy of "Monographie der Spinnen" probably does not exist (any more). The available copies differ in several features as detailed pointed out by Sacher. For this reason it was used a combined version for the reprint of 1988.
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But "Monographie der Spinnen" is far 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.
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 there had been no work of that time which exclusively had spiders as its subject.
Thirdly spider illustrations in the "Monographie der Spinnen" show Hahn to be an above average artist and lithographer.
Finally "Monographie der Spinnen" and "Die Arachniden" are different ways of carrying out the same project and they can both be considered as autonomous works, whereas Brignoli – an important cataloguer in arachnology – regarded "Monographie der Spinnen" only as a sort of blueprint for "Die Arachniden".
The "Monographie der Spinnen" 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.
Die Arachniden – The Arachnids
Until the end of the 18th century all studies of spiders, scorpions and related forms were treated as part of the wider study of entomology, for these were described as wingless insects and included in one genus, the Aranea of Linnaeus, of perhaps 500 different species. Based on Walckenaer's "Fauna Parisienne" (1802) Latreille
established the first set of genera for spiders in his work, which is marking the real beginning of arachnological systematics, and which was extended by Walckenaer into the important "Histoire naturelle des Insectes Aptères" (1837–1847). During the mid-19th century the centre of activity shifted away from France to Germany. An important part of this shift was due to the 14-volume work of C. W. Hahn and C. L. Koch "Die Arachniden" (1831–1848). In contrast to the French manuscripts with their terse descriptions and infrequent illustrations, the two-thousand-plus pages of beautiful coloured plates of this work captured the attention of zoologists everywhere. The important French arachnologist Simon
was incited by the high number of species, described from Germany in "Die Arachniden", while from his native France almost nothing had been done. In particular "Die Arachniden" was very influential in founding a German tradition of active interest in arachnology which flourished for nearly a century. Its major shortcoming, as was realized later, was the lack of a natural scheme of classification, particularly above the family level.
Complete List of Works
(all illustrated by Hahn himself)
- Voegel aus Asien, Africa, America, und Neuholland, in Abbildungen nach der Natur mit Beschreibungen. 19 installments, Lechner: Nuremberg, 1818–1836.
- Monographia Aranearum – Monographie der Spinnen. 8 installments, Lechner: Nuremberg, 1820–1836.
- Naturgetreue Abbildungen zur allgemeinnützigen Naturgeschichte der Thiere Bayerns. Author: Nuremberg, 1826–1828.
- Icones ad monographium Cimicum Nurnberg, Lechner,1826.
- (together with Jacob Ernst von ReiderJacob Ernst von ReiderJacob Ernst von Reider was a German zoologist and botanist.Reider wrote Fauna Boica, oder gemeinnützige Naturgeschichte der Thiere Bayerns with Carl Wilhelm Hahn and Gartenbau als die höchste Kultur des Grund und Bodens in Deutschland .-External links:** Wikisource DE...
Fauna Boica, oder gemeinnützige Naturgeschichte der Thiere Bayerns. Zeh: Nuremberg, 1830–1835. - Die Arachniden. Getreu nach der Natur abgebildet und beschrieben. 2 volumes, Zeh: Nuremberg, 1831–1834 (from the 3rd volume onwards continued by C. L. Koch).
- Die wanzenartigen Insecten. Getreu nach der Natur abgebildet und beschrieben. 3 volumes, Zeh: Nuremberg, 1831–1835 (from the 4th 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: Nuremberg, 1834.
- Ornithologischer Atlas oder naturgetreue Abbildung und Beschreibung der aussereuropäischen Vögel. 6 installments, Zeh: Nuremberg 1834–1836 (continued by H. C. Küster).
- Icones Orthopterorum. Abbildungen der hautflügeligen Insecten. 1 installment, Lechner: Nuremberg, 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.