Sir Walter Farquhar was once visited by an elderly patient who had become convinced that her ill-defined illness might best be treated with a visit to the resort town of Bath, famed for the supposed healing powers of its waters. Farquhar encouraged her, even offering to recommend her to a brilliant doctor in Bath and offering to write him a letter on her behalf outlining her medical history.

The old lady promptly set out for Bath with a friend, but soon began to wonder about the contents of Farquhar's sealed letter; though he had been her physician for many years, he had never told her precisely what was wrong with her. At the first overnight stop, she announced that she was going to open it. Though her companion protested the breach of trust, the letter was opened. "Dear Davis," it read. "Keep the old lady three weeks and send her back again."