Baron Charles De Geer af Leufsta, till Leufsta bruk

Baron Charles de Geer (the family is usually known as De Geer with a capitalized "De"; or in his case, De Geer af Leusta, born in Finspång in Risinge 30 January 1720 – Stockholm 7 March 1778) was a Swedish industrialist and entomologist.

Life

De Geer, who came from a family with strong Dutch connections, grew up in Utrecht from the age of three. He returned to Sweden at the age of 19. He had inherited the entailed manor and important iron-works of Leufsta (Lövsta) in Uppland from his childless uncle and namesake and would substantially increased the wealth of the estate.

Ever since he had received a present of some silk worms at the age of eight, he had an interest in entomology and became a respected amateur entomologist at an early age. His major work was the Mémoires pour servir à l'histoire des insectes (eight volumes, 1752-1778). He was elected a member of the Royal Swedish Academy of Sciences already in 1739, at the age of nineteen, and a corresponding member of the French Academy of Sciences in 1748.

He is buried with his spouse in Uppsala Cathedral. His collections of insects were donated to the Academy of Sciences and now belong to the Swedish Museum of Natural History in Stockholm. He left a library at Leufsta which, among other things, included the papers of Olaus Rudbeck and an important collection of 18th century sheet music. The Leufsta library was acquired by Uppsala University Library in 1986 after a donation by Katarina Crafoord (one of the daughters of Holger Crafoord, the founder of Gambro).

Achievements

De Geer was a great admirer of Réaumur. Hence his modelling Mémoires pour servir à l'histoire des insectes on Réaumur’s work of the same title. It, too, is in French, similarly in large quarto and with the same decorations. The Mémoires deal with 1,466 species, treating life histories, food and reproduction based on careful, patient investigation and analysis of existing literature. There are 238 copper plates. The descriptions are acutely observed.

In nomenclature De Geer was less progressive; Volume 1 of the Mémoires (1752) was too early to employ the binomial system invented by his fellow Swede Carolus Linnaeus. Volume 2 (1771) did not use it, but in Volumes 3 (1773) to Volume 7 (1778) the Linnean system was employed. However, for many species De Geer used two or more words for a specific name, such as Aphis betulae nigro punctata, these names were not binomial in the Linnean sense. He also proposed different names for many species which had previously been named and described by Linnaeus.

It seems that using Linnean names was a concession to usage as in the 1760s and 1770s the Linnean system became increasingly employed, not because De Geer liked the new system. They had differences "not everyone sees things in the same light, and people have the weakness of frequently being too fond of their own opinions" (letter to Linnaeus 16 October 1772) and "if here and there I am still of a different opinion, I am now, as before, asking you not to take it amiss" (letter to Linnaeus 23 February 1774).

Charles de Geer ou Carl de Geer (10 février 1720, Finspång - 20 mai 1778, Lövstabruk) est un biologiste et homme politique suédois.

Biographie

De Geer, dont la famille avait des racines wallonnes, arrive à trois ans à Utrecht et où il fait ses premières études classiques. Il retourne en Suède notamment pour suivre les cours de Carl von Linné à l'université d'Uppsala. Bien que passionné par l'ensemble des sciences naturelles, il se spécialise dans l'étude des insectes et des arachnides.

Il hérite d'un oncle sans enfant d'un manoir et d'importantes forges situées à Leufsta (Lövstabruk) dans l'Uplandia, ce qui le rend fort riche.

Grand admirateur de Réaumur, il fait paraître ses Mémoires pour servir à l'histoire des insectes (de 1752-1778). Il y décrit les mœurs et l'anatomie d'un grand nombre d'espèces (plus de 1 500).

Il devient membre de l'Académie des sciences de Suède en 1739, à 19 ans. En 1748, il est fait correspondant de l'Académie des sciences de Paris. Il est fait Commandeur de l'ordre de Wasa.

Il est enterré, avec son épouse dans la cathédrale d'Uppsala. Il lègue une importante collection d'histoire naturelle à l'Académie des sciences de Suède, elle est aujourd'hui conservée par le Muséum d'histoire naturelle de Stockholm. Il lègue également à la bibliothèque de Leufsta de nombreux livres et notamment des manuscrits d'Olof Rudbeck, dit le vieux, (1630-1702) ainsi qu'une importante collection de partitions de musique du xviiie siècle. Cette bibliothèque est achetée, en 1986, par la bibliothèque universitaire d'Uppsala grâce à une donation de Katarina Crafoord (une des filles d'Holger Crafoord (1908-1982), le fondateur de Gambro, société suédoise d'instruments médicaux).

Friherre, entomolog, bruksidkare och hovmarskalk.

Biografi av Felix Bryk, 1952

http://www.adelsvapen.com/genealogi/De_Geer_af_Leufsta_nr_131

http://www.nad.riksarkivet.se/sbl/Presentation.aspx?id=17342