1911 Encyclopædia Britannica/Katterfelto, Gustavus

KATTERFELTO (or Katerfelto), GUSTAVUS (d. 1799), quack doctor and conjurer, was born in Prussia. About 1782 he came to London, where his advertisements in the newspapers, headed “Wonders! Wonders! Wonders!” enabled him to trade most profitably upon the credulity of the public during the widespread influenza epidemic of that year. His public entertainment, which, besides conjuring, included electrical and chemical experiments and demonstrations with the microscope, extracted a flattering testimonial from the royal family, who witnessed it in 1784. The poet William Cowper refers to Katterfelto in The Task; he became notorious for a long tour he undertook, exciting marvel by his conjuring performances.