From Old World to New World Castor oil can clean you out and light your night. Castor Bean Ricinus communis Heritage Native to tropical Africa, the castor bean plant has been used in herbal medicine since ancient times. The seeds are the source of the all-purpose castor oil. Early African Americans used it internally as a purgative and externally to rid their hair of lice and insects. Castor oil also fueled lamps. In later times, castor oil was used as a key component in a British-made, car-engine oil. The seeds are toxic. Present Use Thankfully, we no longer have to drink weekly doses of castor oil as a cure-all. Although we still use it to combat food poisoning, castor oil has other applications. For example, a commercial anti-fungal medicine includes a derivative of castor oil.   From Old World to New World Medical Technology