Research
Projekte
Raw Plant Materials through the Ages: Hamburg’s Economic Botany Collection as an Archive for the Future
During the 19th century the variety in traded raw plant materials (e.g., food, oilseeds, fibres, tanning agents and dyes, raw materials, medicinals) especially from trade with the tropics had increased so rapidly that it became more and more difficult for merchants to rely solely on their empirical knowledge and common handbooks of commercial products. Hamburg’s merchants also had a lively interest in establishing an institution that was able to provide reliable information on the properties and economic viability of raw plant materials. Therefore a dissertation project investigates the role played by Hamburg’s merchants in the foundation of Hamburg’s Botanical Museum in 1883, asking whether the composition of the botanical collection reflects their influence and to what extent the early orientation towards trade-relevant research might have established a detectable path dependence in the further development of the Museum and Hamburg’s Applied Botany.
The Economic Botany Collection of the Loki Schmidt Haus, which dates back to the former Botanical Museum, is the world’s second largest of this kind after Kew’s. The value of such a collection for the investigation of biogeographical, ecological, phenotypic and genotypic changes, and evolutionary processes is obvious. Furthermore, it offers perspectives and suggestions for research into raw plant materials as substitutes for petrochemical products. An analysis of the historical circumstances under which the samples were acquired and of the notes, photos and other archival materials generated in the collecting context will be carried out, enabling a better assessment of the objects’ evidentiary validity, e.g., in the light of possible collection biases.
Traditional Methods of Mosquito Control Used by Indigenous Populations in Colombia. Assessing the Effectiveness of Plant-Based Repellents and Attractants
The use of plants and natural plant products to repel insects and other arthropods dates back to ancient Egypt and Greco-Roman antiquity. Despite the introduction of synthetic products such as DEET traditional repellents based on indigenous knowledge continue to play an important role in low-income countries. This empirical biological knowledge, handed down over many centuries, is not only of historical interest, but has often been confirmed by modern science.
Also in Colombia several indigenous populations use plant-based repellents the effectiveness of which has not so far been systematically tested. Another method of vector control consists of using bait plants that attract insects, primarily mosquitoes, e.g., by providing nectar. In summer 2016 a doctoral candidate carried out field trials near the city of Candelaria in the Valle del Cauca (Colombia) to test if Parthenium hysterophorus L. acts as an attractant for mosquitoes and Petiveria alliacea L. as a repellent against mosquitoes.
Gottfried Wilhelm Leibniz (1646-1716) as Inventor: Pumped-Storage Plants, 17th-Century Style
Between 1680 and 1685 the polymath Gottfried Wilhelm Leibniz (1646-1716) carried out mathematical, physical and technical investigations to clarify how wind energy might be used for the purposes of the mining industry in the Harz Mountains. One of mining’s major problems consisted in removing the ground water that permanently leaked into the shafts. To this end pumps connected to water mills had been used since the Middle Ages. To optimize this system Leibniz opted for wind energy, the use of which he conceived in two different ways. First, he intended to install vertical and horizontal windmills – the latter hardly known in Europe – to drive the pumps. Second, he planned to use windmills to pump the water mills’ runoff into higher elevation holding ponds from which it could be reused to drive the water mills, forming a circuit. Thus he had in mind a kind of a pumped-storage plant, as wind energy was immediately to be stored as the gravitational potential energy of water, pumped from a lower elevation to a higher elevation. To put into effect his ambitious plans of an “advantageous conjunction of wind and water” (“vorteilhaffte conjunction windes vndt waßers”) Leibniz designed not only horizontal windmills but also control systems to optimize the operation and handling of vertical windmills.
Among other devices Leibniz invented a mechanism that would turn the windmill’s cap automatically to bring the sails into the wind. However, Leibniz’s invention was no windmill fantail, which was invented only later, in 1743 in England, but a completely different mechanism, which can be called a “Leibniz regulator”. Leibniz’s drawing and description of his device have survived in one of his manuscripts and shall be transcribed and edited. Furthermore, a model of the Leibniz regulator has been constructed at a scale of 1:10, which shall be checked in field and wind tunnel experiments for proper operation. A computer animation serves to illustrate the motion sequence.
The Loss of the Medieval Culture of Disputation at Universities and its Impact on the Development of Early Modern Astronomy and Cosmology
The scientific revolution of the 16th to the 18th centuries is marked to a particular degree by the controversy over Copernicus’s cosmological system. Many astronomers considered the Copernican system a mere mathematical model enabling them to calculate the celestial motions more accurately. Otherwise, concerning cosmology they adhered to the geocentric system. However, Copernicus himself had been convinced of the physical reality of his world system and accordingly had offered an alternative to Aristotle’s concepts of gravity, levity and natural elemental motion, which until then had formed the foundation of the geocentric system.
Nevertheless Copernicus’s physics was to a large extent ignored by both adversaries and adherents of his system. As a consequence, in the second half of the 16th and the beginning of the 17th centuries cosmological discussions became starved of content, especially at the universities. This is all the more astonishing when we recall that in the 14th century, that is in the Middle Ages, lively debates had taken place at the University of Paris about the theoretical possibility of a rotating Earth. Compared to the culture of disputation at medieval universities, cosmological discussions of the 16th and 17th centuries often leave the impression of being stereotypical and unmotivated. A joint research project with Prof. Kühne (Munich) addresses the question of the reason that the medieval culture of disputation was lost and what impact this loss had on the development of early modern astronomy and cosmology.