  William Stanley Jevons was born in Liverpool on 1 September 1835. His father Thomas Jevons (1791–1855) was an iron merchant; his mother Mary Anne Roscoe (1795–1845) grew up in an intellectual and artistic milieu. The railway boom crisis of 1847 caused the bankruptcy of the family firm. William Stanley Jevons went to University College School in London in 1850, and in 1851 to University College. He studied chemistry under Graham and Williamson, two pioneers in the development of atomic theory and the theory of molecular motion. Another major influence at University College was Augustus De Morgan (1806–1871), with his courses on mathematics and logic. Jevons left University College without taking his degree. In 1854 he travelled to Sydney, in order to become an assayer at the Australian mint. Jevons devoted much time to private study. His work covered many different areas: railway policy, meteorology, protection, land policy, cloud formation, gunpowder and lightning, geology, etc. Jevons left Australia in 1859 and returned to University College to complete his education. The early 1860s are important for Jevons' intellectual development, and he reports in his diary that he received significant insights in both economics and logic: a “true comprehension of value” (Black 1981: 120, La Nauze 1953) and the “substitution of similars” (Black &amp; Könekamp 1972: 179).