Reverend Edward Stone
- Born
- Unknown
The Reverend Edward Stone was a Church of England vicar who discovered salicylic acid, the active ingredient in aspirin.
Salicylic acid, known as salicin, occurs naturally in plants, especially the willow tree. Its first use was recorded in 400BCE, when Hippocrates prescribed willow leaf tea for women in labour, to reduce the pain of childbirth. By the middle ages, doctors no longer used it, but it was still used in folk medicine.
Stone carried out the first scientific study of the herbal medicine. He tasted the bark from a willow tree, and was struck by its bitterness. He thought it was similar to the bark of the Peruvian cinchona tree, from which quinine was derived in order to treat malarial fevers. Stone thought that this might mean that the willow bark also had similar therapeutic properties.
He also based his supposition on the Doctrine of Signatures, an ancient belief in folk medicine that thought the cause of a disease offered a clue to its treatment. The willow tree was found in damp areas, where fevers were common, and so he thought that the cure may also be close by. Stone investigated a number of botany books to see if this theory was backed up, but could find no information about it.
He decided to collect some willow bark and carry out a number of tests. He dried the bark on the outside of a baker’s oven and once it was dry, pulverised it into a powder. Over the course of five years he gave the powder to about fifty parishioners who were suffering from fevers. He started off with small doses, which he gave every four hours. When he saw that there were no ill effects, and that people’s symptoms eased, he increased the dose until it became effective. He announced his discovery to the Royal Society in a letter, dated 25 April 1763.
I have no other motives for publishing this valuable specific, than that it may have a full and fair trial in all its variety of circumstances and situations, and that the world may reap the benefits accruing from it.
His discovery was explored further by scientists in the following centuries. In 1823, in Italy, the active ingredient, salicylic acid, was extracted and named salycin. In the 1850s, French scientists made salicylic acid but it was found to irritagte the gut. In 1893, German scientists Felix Hoffman and Arthur Eichengrun made a less corrosive version by adding an acetyl group to the acid to reduce its irritant properties. Bayer registed the trade name of aspirin on 23rd January 1899. When the patent ran out in the 1930s, it became a generic drug.
In the 20th century, evidence became available of aspirin’s role in preventing heart attacks and its role in prohibiting prostaglandin production. It is now being investigated to see if it can help in a number of conditions including colon cancer, diabetes and dementia.