• Saul (not Sam) Winstein was the champion of unconventional carbocation chemistry (21 January, p 34).
• In the CareersGuide 2012 sent to subscribers in the UK and US (14 January and 24/31 December 2011), we should have said the right to pursue happiness is in the US constitution.
• In the feature “Creative sparks” (14 January, p 42), the photograph on page 45 should have been credited to “Thomas Struth/Art Institute of Chicago 2, Chicago 1990”.
