Passage II

Origins of Aspirin

When a plant is attacked by bacteria, fungi, or insects, it produces chemicals, called salicylates, that help the plant produce enzymes or toxins capable of destroying the plant's attackers. Salicylates may also play a role in the plant's ability to regulate its temperature; in effect, helping the plant tolerate heat and cold. Humans have used the salicylic acids found in plants, particularly in the bark of the willow tree, to fight disease and to reduce fevers.

The first known references to willow bark's medicinal use date from ancient Egypt and Sumeria. On a Sumerian stone tablet from 3000 BCE, lists willow among dozens of plants used to treat illnesses. An Egyptian papyrus from approximately about 1534 BCE refers to willow's use as an all-purpose medicine.

Though willow trees are often found near water and have become religious symbols in many cultures, its medicinal use gradually fell out of favor in Europe. Apothecaries increasingly preferred the imported bark of South American cinchona trees as a fever reducer, even though willow grew abundantly throughout Europe.

The high cost of importing cinchona bark however, was expensive. Consequently, in the mid-1700s, English minister Edward Stone had began to seek a substitute. He noted that the bitter taste of willow bark was reminiscent of the bitter taste of cinchona bark. Known also for his interest in astronomy, Stone pulverized some willow bark and adds its powder to a liquid. He administered the medicine to people suffering from fevers, he then noted that it worked.

As the field of medicine evolved, so did the use of willow bark. Searching for a way to make the salicylic acid in willow bark less abrasive to the stomach, in 1853 French chemist Charles von Gerhardt created a synthetic version. Decades later, German chemist Felix Hoffmann combined synthetic salicylic acid with acetic acid, inventing a consumer-friendly powdered formula that would come to be known as aspirin.