Johannes Fåhraeus, Amsterdam merchant and representative of the Swedish naturalist Carl Peter Thunberg

The development of science in the seventeenth and eighteenth century is marked by the exchange of ideas and research results on a transnational scale. This led to an extensive exchange of letters and – in the case of natural history – of materials such as (dried) plants, seeds, and minerals. Logistical support by all kinds of go-betweens was essential in this process. This is where merchants could be useful. This article explores this logistical role of merchants, based on a collection of thirty-nine letters from Sweden-born Amsterdam merchant Johannes Fåhraeus to Swedish botanist Carl Peter Thunberg. These letters show that for fifteen years Fåhraeus operated as Thunberg’s representative in Amsterdam. Due to his transnational commercial contacts, he could offer Thunberg financial services, arrange shipping of letters and parcels to and from Sweden, and provide political and economic information. This role of go-between implied a real bond of trust. Fåhraeus’ activities for Thunberg demonstrate that merchants played an important facilitating role in the development of modern science.