Adolf Müllner is best known in German literature for his “fate tragedies” (Schicksalstragödien) Der neunundzwanzigste Februar (1812, revised as Der Wahn, 1818; the twenty-ninth of February) and Die Schuld (1813; Guilt, 1819). His sole contribution to detective fiction is his short novel Der Kaliber (1828; The Caliber, 1999), which is often called the first detective novel in German literature. The story is told in the first person, the narrator being the examining magistrate charged with investigating the murder of a young man who is killed in the presence of his brother. The brother believes himself guilty, but he is proved innocent because the bullet that killed his brother was of a larger caliber than the ones shot by his pistol.
This work was kept from complete oblivion by being reprinted in obscure anthologies several times, the last as late as 1908. It seems to have had little influence and is virtually unknown in the English-speaking world. Its interest is thus primarily that of a historical curiosity.