
Otto Hahn (petrologist)

Otto Hahn (1828 – 1904) was a German petrologist, geologist, lawyer and author. His father was Johann Franz Gottlieb Hahn (1789 – 1844). His great-grandfather was Christian Tobias Hahn (1759 – 1837), who was the half-brother of Philipp Matthäus Hahn.
Hahn started his career as a lawyer. He eventually left the legal profession for the natural sciences. The University of Tübingen awarded him a doctorate for his participation in the Eozoön canadense controversy. He was an active member of The New Church (Swedenborgian) and was a Neptunist. He published "Die Urzelle" in 1879. His book "Die Meteorite (Chondrite) und ihre Organismen", published the following year in 1880, was a major work in the field of meteoritics that included 142 black and white photomicrographs of chondrite thin sections. In this latter work Hahn proposed the theory that the chondrites consist entirely of fossilized organic remains of life-forms, namely, fossilized sponges, corals, and crinoids. In addition, he claimed that the iron meteorites have an organic origin and that they are the petrified remains of a fungus or plant that was permeated with iron-nickel alloys, e.g. similar to ichnotaxa like the "Chondrites".