Humboldt an <persName xmlns="http://www.tei-c.org/ns/1.0" ref="https://edition-humboldt.de/H0001968 http://d-nb.info/gnd/11948496X">Marc-Auguste Pictet</persName>, <placeName xmlns="http://www.tei-c.org/ns/1.0" ref="https://edition-humboldt.de/H0005176 https://www.geonames.org/2951825">Bayreuth</placeName>, 24. Januar 1796 (<bibl xmlns="http://www.tei-c.org/ns/1.0" corresp="https://edition-humboldt.de/VMWUPZ29">La Roquette 1865</bibl>, 4).