vertex; vortex. A “vertex” is either (1) the apex or highest point of something, or (2) where two sides of a figure meet to form an angle. A “vortex” is swirling matter, such as a whirlpool or a tornado. The two terms are confounded fairly often — e.g.: o “Members of the purported Seattle cell have . . . made pilgrimages to the North London Central Mosque in Finsbury Park, thought to be at the vortex [read ‘vertex’] of militant Islamic recruiting in Europe.” Mike Carter et al., “Seattle Militants Investigated for Possible Ties to al-Qaida,” Seattle Times, 12 July 2002, at A1. o “San Diego has been in the vortex [read ‘at the vertex’] since Americans decided, a decade ago, that health care was part of the free-enterprise system and could be merchandised. . . . San Diego jumped out to an early and contentious lead in managed care and even became a proving ground.” Neil Morgan, “Nation’s $1.3 Trillion Issue,” San Diego Union-Trib., 14 July 2002, at B3. o “No longer does Tom Osborne command a squad of 150 young men on national television or stand at the vortex [read ‘vertex’] of Nebraska’s football obsession.” Matt Kelley, “Osborne Is at Home in the House,” Omaha World-Herald, 21 July 2002, at A1. Language-Change Index — “vortex” misused for “vertex” (meaning “summit”): Stage 1. For information about the Language-Change Index click here. ————————————— Quotation of the Day: Sometimes we concentrate so hard on our subject that we tend to lose sight of our purpose. Ernst Jacobi, Writing at Work: Dos, Don’ts, and How Tos 5 (1976).