ABSTRACT
Thoughtful readers may often wonder how humankind discovered the medicinal virtues of so many different plants. After teaching about drugs from natural sources for several years at the University of Nebraska, I knew the answer. Every few weeks during the summer months, another package would arrive in the mail containing some fragments of the woody rhizome and roots of a "peculiar" plant that, as explained in the accompanying letter, caused an unusual, acrid, tingling sensation on the tongue when it was chewed. Some Nebraska farmer, a close observer of nature, had once again discovered a potentially useful plant by the age-old process of trial and error.
