Boundaries
by Jack Nisbet

Jack Nisbet is the author of The Mapmaker's Eye, Sources of the River, Purple Flat Top, Singing Grass, Burning Sage and Visible Bones. His newest, The Collector, is due out in October.

David Thompson's Eyes
December 2007

During the winter [of 1789-90] I became Mr. Philip Turnor's only assistant and thus learned practical astronomy under an excellent master of the science...By too much attention to calculations in the night, with no other light than a small candle, my right eye became so much inflamed that I lost its sight... David Thompson,

Travels in Western North America 1784-1812

Throughout the days of his long productive life, fur agent and north Columbia explorer David Thompson spent time watching the landscape, observing wildlife, aiming a musket to bring down game, sawing and sewing wood in the course of various building projects, peering through a sextant or telescope to determine where he was on the planet, performing neat mathematical calculations on unlined paper, reading, and, especially, writing. Since each of these activities involve clear vision, it comes as somewhat of a shock to realize that, from the age of 19 onward, Thompson managed to accomplish them with only one eye. Could he have been exaggerating a little bit when he stated that he lost the sight in his right eye during the winter of 1789-90? Did anyone else ever comment on the state of David Thompson's vision?

Someone did. In 1850, the respected Montreal physician Dr. Henry Howard published an account of his treatment of Thompson's problem in a volume titled The Anatomy, Physiology and Pathology of the Eye. Howard wrote that the 73-year-old Thompson, well known as an astronomer and surveyor for the International Boundary Commission

was led by his daughter to my surgery on the 24th of February 1843. He stated that he had been blind in his right eye since February 1789 and did not expect I could do anything for it, but that the sight of his left eye had always been good up to the past three months, when it became a little cloudy, which cloudiness gradually increased up to ten days previous to his coming to me on which morning (the 14th of February) he awoke so perfectly blind as not to know it was daylight. He stated that he had applied to two well known medical men who professed to know something of the diseases of the eye and they assured him nothing could be done for him.

Dr. Howard was not so easily discouraged. He examined Thompson's left eye and found a simple capsule-lenticular cataract "full ripe for operation." When he peered into Thompson's blind right eye, he observed a curved scar in the center of the right cornea. The scar was so surrounded by lymph that it rendered the whole cornea opaque, hiding most of the iris. Doctor and patient agreed that they would try to treat both eyes.

For the next three weeks, David Thompson's daughter guided him to Dr. Howard's office for daily visits. After that time, the surveyor had recovered enough of his sight to make the trip on his own. By the time three months had passed, Thompson was able to read and write during daylight hours, although Dr. Howard prohibited him from attempting either activity by candlelight. It during this period when Thompson told the doctor that

on a previous evening he had seen a particular star with his right eye for the first time since he was 19, I then examined his eyes and found scarcely a vestige of cataract remaining in the left eye, and the right cornea so clear that the whole of the iris and pupil were visible, even the cicatrix [that crescent scar] was much smaller, indeed not more than half its original size.

The treatment that brought about this miraculous cure was the same for both eyes. (Warning: Do Not Try This at Home)

Every day Dr. Howard began by fumigating his patient's eyes with hydrocyanic acid, a compound often used in those days for fumigating contaminated clothing or food.

Next, Thompson's "eye brows, lids and temples were brushed with a solution veratria." This solution consisted of a grayish-white mixture of poisonous alkaloids derived from pounded sabadilla seeds. These seeds (also spelled "sapodilla"), taken from the fruit of a tropical American evergreen, have long been known as an irritant that makes the eyes water copiously.

According to Dr. Howard, "Sparks of electricity were drawn from round the orbit about three times a week." The use of static electricity generated by various methods has been a staple of medical treatments ever since it was discovered.

"Occasionally I dropped on the conjunctiva the two grain solution of atropine." Atropine is a powerful plant medicine derived from various members of the potato or nightshade family (Solanaceae); familiar sources include mandrake and belladonna. Atropine, both organic and synthetic, has a long history as a treatment for wounds, gout, pain, and sleeplessness; in Thompson's day it was used as an anesthetic before surgery. Moderate doses of atropine have been used since Roman times to dilate the pupils.

In the early stages of the Thompson case, Doctor Howard had employed even more radical methods. "For the first two weeks he took every morning a wine glass full of the infusion of gentian containing a small quantity of the sulphates of magnesia and sulfuric acid." Blue gentian, derived from an alpine plant common in the northern hemisphere, is still valued for its antiseptic qualities. But it's hard not to think that the diluted sulfuric acid, delivered directly onto his patient's eyeballs by Howard's version of an eyecup, wasn't the key factor in burning away the cataract and dissolving some of the scar tissue from the injury that had impeded Thompson's right eye for 53 years.

Thompson, being Thompson, found time to chat with the worldly Dr. Howard while undergoing these gruesome daily treatments. In one of the last entries in his Travels manuscript, while contemplating how a goose he shot one spring on Hudson's Bay could have retained wild rice from Minnesota in its stomach, Thompson included a brief nod to the man who restored his sight.

(Note: Conversing with Surgeon Howard of Montreal on the great distance the Wild Geese fly without digesting the rice in their stomachs, he related to me an experiment on digestion...)

Surgeon Howard went on to recount a rather whacky trial involving hounds and fresh meat, but it couldn't have been any stranger than the procedures he performed that very day on David Thompson's eyes.

Yet those experimental treatments somehow succeeded. It wasn't until 1850 that the light of Thompson's eyesight faded out completely, and he could no longer put pen to paper. Thanks to Dr. Howard's work, and perhaps a generous helping of good luck, David Thompson was able unfold dozens more eccentric and entertaining stories in his Travels manuscript, many of which enrich what we know about his travels through the North Columbia Country. So here's to sapodilla seeds and electric sparks, blue gentian and belladonna, plus a wee wineglass of sulfuric acid in the morning; with their help, we hope that the New Year shines through as clear as the brightest star.

Illustration by Emily Nisbet

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