 Humboldt's scientific excursion up the Rhine resulted in his 1790 treatise "Mineralogische Beobachtungen über einige Basalte am Rhein" (Brunswick, 1790) ("Mineralogic Observations on Several Basalts on the River Rhine").Humboldt's passion for travel was of long standing.Humboldt's talents were devoted to the purpose of preparing himself as a scientific explorer.