D’Alembert already called the curve a lemniscate in the *Encyclopédie* (1765, vol. IX, [p. 382](https://archive.org/stream/encyclopdieoud09alem#page/382), [fig. 41](https://archive.org/stream/Recueildeplancht5Dide#page/n68)) — this must be where Gerono got his terminology.