During the 1820s, Humboldt composed numerous manuscripts in preparation of his <hi xmlns="http://www.tei-c.org/ns/1.0" rendition="#i">Geognostische Versuche über die Ausbreitung der Gebirgsarten in beiden Erdhälften</hi> (1823). The “Examen des hypothèses géologiques considérées dans le rapport de leur concordance avec les principes de la Mécanique, de la Physique et de la Chimie” (over thirty pages long) (<ref xmlns="http://www.tei-c.org/ns/1.0" target="http://kalliope-verbund.info/DE-611-HS-1035140">Papers Large Box 5</ref>) deals among other things with writings on thermodynamics by Joseph Fourier and Siméon Denis Poisson. The <ref xmlns="http://www.tei-c.org/ns/1.0" target="http://archiv.bbaw.de/archiv/archivbestaende/abteilung-nachlasse/nachlasse/humboldt_alexander">archives of the Berlin-Brandenburg Academy of Sciences and Humanities</ref> hold a copy of the French edition of the <hi xmlns="http://www.tei-c.org/ns/1.0" rendition="#i">Geognostische Versuche, </hi>interleaved with numerous handwritten notes.