From Seed to Seed:
Plant Science for K-8 Educators

Aspirin. In the fifth century B.C., Hippocrates, a Greek physician, discovered that chewing on willow bark relieved pain. He began using powdered willow bark to lower fevers and ease the pain of childbirth.

Let's fast-forward to the mid-1700s, when the beneficial properties of willow bark were once again "discovered." The active substance was determined to be salicin, or salicylic acid. (Salicin is a derivative of the Latin word Salix, which is the genus name of willows.) Willows (and a number of other plants) produce salicylic acid, most likely as part of a defense against infection.

It was soon discovered that salicylic acid on its own caused stomach upset. However, combining it with acetyl chloride produced a less irritating product. Eventually manufacturers began using spirea as the source of salicylic acid. The name aspirin is derived from the words acetyl chloride and SPIRea.

Today aspirin is used to relieve pain and reduce inflammation. Because it interferes with blood clotting, it is believed to cut down on the risk of heart disease and increase the survival rate for heart attack victims. New research indicates that it may also reduce the risk of colorectal cancer.