On the 25 April 1763 a letter was sent from Chipping Norton in Oxfordshire to the Right Honourable George Parker, Earl of Macclesfield, then President of the Royal Society, extolling the use of willow bark in curing agues and other feverish complaints. The writer describes how about a pound of bark taken from a common white willow (Salix alba) was dried in a bag over a baker's oven for more than three months, pulverized and then used to alleviate the agues, ‘intermitting disorders’ and distempers of 50 afflicted people. The undoubted medicinal properties of bark from willow and other Salix species were not new. They were known to a number of preindustrial cultures and also, in a more systematic way, to the medical philosophers of classical Greece and Rome. However, by the eighteenth century in Western Europe, they were in disuse or had been relegated to the level of folk medicine.
The letter, duly printed in Philosophical Transactions, is often credited with having brought the anti–inflammatory, antipyretic and analgesic properties of these barks, to the attention of the emerging chemists of the late eighteenth century. Attempts to identify the active principles, and then to synthesize them, led to the discovery of salicylic acid and its derivatives, and eventually to the introduction of acetyl salicylic acid––aspirin––possibly the most widely used of all synthetic drugs. This history is periodically reviewed both for general and specialist audiences; the seminal letter is referred to whenever there is a new monograph on these anti–inflammatory drugs, and is the subject of frequent queries to the Royal Society's library. It would seem, therefore, to be useful to remove a confusion surrounding the name of its author, who has been variously referred to as either Edward or Edmund Stone.