Engraving of Girolamo Cardano (1501-76), Italian mathematician and physician. Cardano was the illegitimate son of a Milanese lawyer, his birth holding back his career as a talented physician. He is best known, however, as one of the greatest algebraists of his time. He recognised both negative and complex roots of equations, and gave a general algebraic method for solving cubic equations (Cardano's solution). He was accused of plagiarism by Tartaglia, but such claims have been contested. He was also a major figure in chemical thought. He made more enemies than friends, however, including his second son who he had banished for being 'a youth of evil habits'.