Medical miracle claimed for Canadian explorer.

In his long and remarkable life (1770–1857), David Thompson worked for the Hudson’s Bay Co. and the Northwest Co., traded with Indians from Hudson Bay to the Pacific and spoke both Cree and Blackfoot. He learned the science of practical astronomy, which allowed him to calculate coordinates of latitude and longitude, as he explored regions then known only to the Indians. Later, he used these observations to create a map of lands now known as Western Canada. Thompson, who had seven years of formal schooling, achieved all this despite a disability: In February 1789, while mastering practical astronomy, he lost the sight in his right eye. In 1812, Thompson left the west and settled near Montréal, Quebec, where he led the team of British surveyors that worked with American counterparts after the War of 1812 to draw a border between present-day Cornwall, Ontario and Lake-of-theWoods. He went bankrupt in 1836, at age 66, and he and his Métis wife, Charlotte Small, endured an impoverished old age in and around Montréal. He contracted cholera in the early 1840s and survived, but then, toward the end of 1847, the vision in his good left eye became blurred. One morning in February 1848 he awoke completely blind. Fortunately, a son-in-law paid for medical expenses. Montréal physician, Henry Howard, treated Thompson and his summary of the case later appeared in the book, The Anatomy, Physiology and Pathology of the Eye. “I examined his eyes,” Howard wrote, “and found he had capsulo-lenticular cataract of the left eye, fully ripe for operation; and a cicatrix in the centre of the right cornea, so surrounded by lymph as to render the whole of the cornea opaque, causing it to appear as though the sclerotic extended over the front of the eye; not one portion of the iris was observable through it.” Howard treated Thompson daily in the following manner: “His eyes were fumigated with hydrocyanic acid and his eyebrows, lids and temples brushed with the solution of veratria; sparks of electricity were drawn from round the orbit about three times a week and occasionally I dropped on the conjunctiva the two grain solution of atropine. For the first two weeks, he took every morning a wine glass full of the infusion of gentian, containing a small quantity of the sulphate of magnesia, and sulphuric acid.” After three weeks of treatment, Thompson had regained his vision to the point where he could walk unassisted to Howard’s office. After three months, he was able to read and write. One day he told the physician that: “On the previous evening he had seen a particular star with his right eye for the first time since he was of the age of 19.” On examination, the cataract had disappeared, the corneal edema had cleared and the iris could be visualized This curious case recently came to the attention of Dr. John Speakman, a former staff ophthalmologist at Sunnybrook Hospital in Toronto, Ontario. Speakman concluded that the physician’s description of the problems with