August Klotz (1864-?) was a German schizophrenic outsider artist and one of the "schizophrenic masters" profiled by Hans Prinzhorn in his field-defining work Artistry of the Mentally Ill.
He was the son of a prosperous Swabian merchant, and worked in his father's business as a wine and champagne salesman for many years. Besides a case of gonorrhea, he was healthy until an attack of influenza in 1903, at which point he fell into a deep depression, involving hallucinations and even self-mutilation.
He was placed in an asylum where he began drawing right away. He rubbed figures into his wallpaper with fat and called them "Freemason signs." He may have also experienced an unusual form of grapheme-color synaesthesia in which letters correspond to numbers, which when added up correspond to colors. Klotz loved playing word games, and this same playfulness is also apparent in his drawings and watercolors.
Unlike most outsider artists, Klotz displayed little consistency in his work. Prinzhorn saw him as a shining example of the creative impulse at its most basic. "He always allows himself to be driven by momentary impulses so that his pictures generally incorporate the unconscious components of pictorial creation in a rare state of purity... he composes completely passively, almost as a spectator, and afterward tries to interpret his configurations" (Prinzhorn 1972, p. 143).