Revalenta arabica

Revalenta Arabica, or Ervalenta, was a preparation sold in the 18th century as an empirical diet for patients, extraordinary restorative virtues being attributed to it.

The product that was mass-marketed was, in reality, only a preparation of the common lentil, its first name being formed for disguise by the transposition of its earlier botanical name, Ervum lens.

While lentils are a healthy and nutritious food, Revalenta Arabica's value was about similar to the common pea-meal (or ground split peas).

The original plant of the product was unknown for a long time, until the German explorer of Africa and botanist Georg Schweinfurth discovered Glossostemon bruguieri as its source.

Plant and usage had been described in Firdous al-Hikmah ("Paradise of Wisdom") of Ali al-Tabari, a medicinal encyclopedia from the 9th century AD.