PHILADELPHIA, JACOB (b. 1720 or 1735–after 1783), Colonial American physicist, mechanic, and kabbalist. Philadelphia's family name and the year when he assumed the name of his native city is unknown. He may have been educated by a Dr. Christopher Witt, a Rosicrucian mystic and anchorite survivor of the German Pietist mystic sect known as the "Women of the Wilderness." Witt was known to be a correspondent of the Duke of Cumberland, who later became Philadelphia's patron in England. After his patron's death in 1758, Philadelphia toured England, lecturing and conducting experiments to great acclaim, and later lectured throughout Europe. Considered a powerful magician by the ignorant, Philadelphia nevertheless refused to lecture at the University of Goettingen (1777) after a satirical poster campaign derided him as a miracle worker and magician. He supposedly last lectured in Switzerland in 1781. In 1783 he applied to the Prussian court for a license to form a Prussian-American trading company.
J.F. Sachse, in: ajhsp, 16 (1907), 73–83; J.R. Marcus, Early American Jewry, 2 (1953), 83–89.