Carl
Cahn-Bronner 1930. Image courtesy: Fam. HottingerThe history of the collection of Carl Cahn-Bronner (1894 - 1979)
Carl
Cahn-Bronner 1930. Image courtesy: Fam. Hottinger
Source of information: Hottinger, L. (2011). Die Naturaliensammlung Carl Cahn-Bronner, unpublished letter (in german), dated from 25.2.2011.
Carl Cahn-Bronner, an uncle of the Basel micropaleontologist Lukas Hottinger, grew up in Strassburg in a family, that brought forward many medicals. Also Carl started studying medicine and assisted his father Arnold Cahn, who was professor for inner medecine at the university in Strassbourg. Together, they worked in a lazaret, which had been installed in a church in Strassbourg in order to treat war victims during the world war I. After Alsace was re-conquered by the French in 1918 all German academic families were forced to leave the country. As a young medical Carl settled in Bad Homburg, where he initiated his collection of natural objects, at that time mainly fossils and minerals from local sites in southern Germany. From 1936 onwards, suppression by the Nazi regime on the medical familie(s) became overwhelming, which led Carl to leave the country. He first immigrated to Milan, Italy, where he had also carried his collection.
Carl Cahn Bronner
1937. Image courtesy: Fam. Hottinger
But also in the fascist climate at that time in Italy, the political situation became worse after 1939, and Carl decided again to emigrate. He first embarked to Havanna (Cuba) and awaited for an immigration permit for the U.S.A. While leaving Italy, the Natural History Museum of Milan inspected the collection of Cahn-Bronner and confiscated the most beautiful and valuable objects including fossils from the fameous Holzmaden site. After the war Lucas Hottinger contacted the curator of the Natural History Museum of Milan, Vially, who was in charge for the collections. Inquiring about the confiscated fossils, however, did not produce any satisfactory answer where the material has been gone, and most probably specimens were put on sell on the fossil market.
From the move from Milan to Havanna a box remained containing smaller objects of Cahn-Bronner's collection, which was by then deposited in the cellar of the house of Lucas Hottinger's father. The box contained specimens of halite, which however, have lost all their labels due to decay in the humidity of the room. Unfortunately, the salt brine has also destroyed all other lables and notes to the accompanying objects, but it was this box, that Uncle Carl had doned his nephew Lucas. These were the initial moments, when Lucas Hottinger raised interest in natural objects and earth sciences as a child.
After immigration to the U.S.A. Carl Cahn-Bronner settled down in the city of Chicago, where he resided in a small wooden house not far from the university. Here, he could dwelve in his hobby and enlarge his natural collections almost without any limit, as he owned an entire floor of the house mentioned to his disposal.
During roughly three decades a big collection of natural objects accumulated, which includes lots of different organic and inorganic objects, that din't require any fluids to be preserved.
In the late sixties Hottinger's uncle had to give up the house in Chicagoas he was no longer able to cope with the housework on his own. He got in contact with the Field Museum in Chicago, which, however, was only interested in the specimens from Europe, as they had only few collections from there. Hence, a considerable number of the fossils that Lukas Hottinger collected during his field work for his PhD dissertation and sent to his uncle, stayed in Chicago (mainly including Paleogene and Jurassic molluscs, echinoderms and corals). The remaining collection he bequeathed Hottinger on condition to pack it in his old house and send it to Basel. In the suite, Cahn-Bronner's nephew flew to Chicago and within a week he packed everything into cardboard boxes as the house was already sold and had to be cleared quickly. The boxes were shipped to Basel in a container and were unloaded in the garage of Hottinger's house in Allschwil near Basel. Hans Schaub, the former director of the Natural History Museum Basel, couldn't be made interested in those collections, probably with the thought in head that the Museum would have to take part in the shipping costs.
The collection from Carl Cahn-Bronner comprises minerals and ores including trinitite specimens from the 1945 New-Mexico site and unranium-minerals, a few pieces of sedimentary rocks with special features as for example Liesegang concretions, fossils and recent hard parts of marine organisms, especially shells from molluscs. The collection of fossils comprises specimens from Precambrian banded iron formation all way through the Quaternary, with many fine fossils from North American Paleozoic formations. Notably, there are some fine plant fossils from Carboniferous sites in the U.S.A., fossils from Mazon Creek, and silicified plant remains from the famous petrified wood in Arizona. The majority of the pieces is registered with a card file and specimens are all labelled: a small white spot with a black Indian ink number. Those relegate to a catalogue which is sorted by themes or stratigraphic units. It contains approximately ten thousand numbers.
Lukas Hottinger and his uncle discussed many times about the concepts that determined the collection activity of Cahn-Bronner. Whenever possible, natural assemblages of minerals from specific mines or fossils from particular locations should be inventorized together. These assemblages had priority to the systematic completeness of the collected material. Notably, an entire room of the house in Chicago was devoted to the collection of fluoresceing minerals.
In the following decades Hottinger couldn't find the time and space to restore such a big collection as the one of his uncle. Some pieces however, he used for his paleontology classes at the Geological-Paleontological Institute of the University of Basel, especially recent corals, fossil echinoderms as well as cephalopods and trilobites from the famous Paleozoic outcrtops or formations. Micropaleontological material is only underrepresented in the collection including only some specimens of Triticites and fusulinids. These were the reasons, why for long years, one part of the collection was deposited in the collections of the Geological-Paleontological Institute, while the other part resided at Hottinger's home, together with the catalogue and some rather rare publications, that Cahn-Bronner used to determine fossils. In 2011 Lukas Hottinger donated the natural collection of Carl Cahn-Bronner to the Natural History MuseumBasel without any further conditions together with some of Hottinger's own material.
In 2012, about one year after passing away of Lukas Hottinger in September 2011, both parts of the Cahn-Bronner collection, i.e. those from Lukas Hottinger's home address and those stored in the Geological-Paleontological Institute were transported to the Natural History Museum in Basel. In spring 2013 all specimens were carefully cleaned and stored in collection boxes together with the available information and labels. Prior to cleaning specimens were fotographed in the original state together with their labels, with the digital images to be stored in the digital archive of the NMB. This treatment is described in an internal report by Hannes Rösti (2013). Thereafter the collection of Carl Cahn Bronner was split into three parts: Recent corals, mollusks and other preparations are now curated alongside the biological collections of the NMB. Fossils are integrated in the paleontological collections of the NMB, while all minerals and ore specimens are curated in the mineralogical collections of the NMB. Also the card files were cleaned by an external company. After treatment they are topically re-sorted, re-packed into new card-boxes and now are curated alongside the respective collections in the different departments of the museum.