Gulp: Adventures on the Alimentary Canal

by Mary Roach

  * The human digestive tract is like the Amtrak line from Seattle to Los Angeles: transit time is about thirty hours, and the scenery on the last leg is pretty monotonous.

  † “It can even vomit,” boasts its designer. No reply arrived in response to an e-mail asking whether and into what the Model Gut excretes.

  * More recently, the digestive action of a healthy adult male obliterated everything but 28 bones (out of 131) belonging to a segmented shrew swallowed without chewing. (Debunking Fletcher wasn’t the intent. The study served as a caution to archaeologists who draw conclusions about human and animal diets based on the skeletal remains of prey items.) The shrew, but not the person who ate it, was thanked in the acknowledgments, leading me to suspect that the paper’s lead author, Peter Stahl, had done the deed. He confirmed this, adding that it went down with the help of “a little bit of spaghetti sauce.”

  * The Beaumont findings were pointed out to Fletcher in a discussion that followed a lecture of his at a 1909 dental convention in Rochester, New York. “It made no practical difference whether the food was previously masticated very thoroughly, or whether the morsel . . . was introduced . . . in one solid chunk,” said an audience member. Before Fletcher could reply, two more doctors chimed with opinions on this and that. By the time Fletcher spoke again, two pages farther into the transcript, the mention of Beaumont was either forgotten or conveniently ignored. At any rate, Fletcher didn’t address it.

  5

  Hard to Stomach

  THE ACID RELATIONSHIP OF WILLIAM BEAUMONT AND ALEXIS ST. MARTIN

  THREE FAMOUS ENGRAVINGS depict Alexis St. Martin in his youth. I’ve seen them many times, in biographies of his surgeon William Beaumont, in Beaumont’s own book, in journal articles about the pair. As detailed as the artworks are, you can’t tell what St. Martin looked like from examining them. All three woodcuts are of the lower portion of his left breast, and the famous hole. I could pick St. Martin’s nipple out of a lineup before I could his eyes. I suppose this makes sense; Beaumont was a researcher and St. Martin his subject—more a body than a man. But the two knew each other across a span of thirty years. They lived together on and off for a decade. Over all this time, did no fondness develop? What exactly was their relationship? Was St. Martin mistreated, or was digesting for science the cushiest job a hard laborer could hope for?

  The two first met in June 1822, at a company store on Mackinac Island, part of a trading post owned by the American Fur Company. St. Martin was a French Canadian voyageur—an indentured trapper—hauling pelts by canoe and on foot through the woodsy landscape of the Michigan Territory. St. Martin retained little memory of the pair’s historic meeting, lying, as he was, barely conscious on the floor. Someone’s gun had discharged accidently, spraying a load of duck shot into St. Martin’s side, and Beaumont, the army surgeon assigned to the nearby garrison, had been called down to help.

  The ducks of Mackinac Island are apparently not easily taken down. “Found a portion of the Lungs as large as a turkey’s egg protruding through the external wound, lacerated and burnt, and below this another protrusion resembling a portion of the Stomach, what at first view I could not believe possible to be that organ in that situation with the subject surviving, but on closer examination I found it to be actually the Stomach, with a puncture in the protruding portion large enough to receive my forefinger, and through which a portion of his food that he had taken for breakfast had come out and lodged among his apparel.” Thus reads Beaumont’s somewhat windy account of the injury.

  Through that puncture—and in the slop of half-digested meat and bread suddenly visible in the folds of St. Martin’s wool shirt—lay Beaumont’s ticket to the spotlight of national renown. Italian digestion experimenters had pulled food in and out of live animal stomachs, soaked it up in sponges on strings, even regurgitated their own dinners, but St. Martin’s portal presented an unprecedented opportunity to document the human juices and processes in vivo. (We will step into the stomach in earnest in chapter 8; for now, it’s medicine’s oddest couple that I wish to explore.)

  Beaumont was thirty-seven and on the lookout for something a little glossier than the anonymous rustic toil of an assistant surgeon at a military outpost. Exactly when he realized the value of the St. Martin hole—and how assiduously he did or didn’t work to close it—remain matters of conjecture. The recollection of a man named Gurdon Hubbard, the only eyewitness whose account of that morning remains, suggests the realization occurred earlier than Beaumont claimed. “I know Dr. Beaumont very well. The experiment of introducing food into the stomach through the orifice, purposefully kept open and healed with that object, was conceived by the doctor very soon after the first examination.”

  Beaumont denied this. In his journal, he claims to have tried “every means within my power to close the puncture of the Stomach.” I imagine the truth lies midway between. Something closer to Hubbard’s version would serve to explain Beaumont’s puzzling dedication to a man he did not know and about whom he would have been inclined, by birthright, to care little about. St. Martin was a mangeur du lard—a “porkeater,” the lowest class of voyageur. Yet when county funds for St. Martin’s hospital care ran out, in April 1823, Beaumont moved him into his family’s home. The explanation he gives in his journal was that he did so “from mere motives of charity.” That I heavily doubt.

  St. Martin was put to work around the house as soon as he was well enough. From the beginning, Beaumont had an eye on the fistula, more or less literally. “When he lies on the opposite side I can look directly into the cavity of the Stomach, and almost see the process of digestion,” wrote Beaumont in his journal. I would love to know how the experimental protocol was first broached. St. Martin had no understanding of scientific method. He was illiterate and spoke little English. He communicated in a French Canadian patois so heavily accented that Beaumont, in his notes from the day of the shooting, transcribed “St. Martin” as “Samata.” Beaumont kept diaries but neither I nor medical ethicist Jason Karlawish, who has written a fine and sleuthfully researched historical novel about the pair, could find mention of St. Martin’s initial reaction to the unusual proposition.

  In “Working Ethics: William Beaumont, Alexis St. Martin, and Medical Research in Antebellum America,” historian Alexa Green explains the men’s relationship as clearly one of master and servant.” If the man wants to push a piece of mutton through your side, you let him. Other duties as assigned. (When St. Martin had healed sufficiently that the premise of providing continuing care began to seem a ruse, Beaumont provided a salary.)

  For two people so firmly distanced by class and employment structure, Beaumont and St. Martin inhabited a relationship that could be oddly, intensely intimate. “On applying the tongue to the mucous coat of the stomach, in its empty, unirritated state, no acid taste can be perceived.”* The one image I eventually found of Alexis St. Martin as a whole young man is in a painting by Dean Cornwell entitled Beaumont and St. Martin—part of the Pioneers of American Medicine series commissioned in 1938 by Wyeth Laboratories for an ad campaign. Despite the unfortunate side-parted bob that St. Martin appeared to stick with all through his adult life, the man as Cornwell rendered him is striking: broad cheekbones, vertically plunging aquiline nose, and a firmly muscled, deeply tanned chest and arms. Beaumont is dashing but dandified. His hair is oddly waved and piled, like something squeezed from a cake decorator’s bag.

  Cornwell’s painting is set at Fort Crawford, in Michigan Territory, during St. Martin’s second stint in Beaumont’s employ, around 1830. At this stage in his digestive explorations, Beaumont had been trying to determine whether the gastric juice would work outside of the stomach, removed from the body’s “vital force.” (It does.) He filled vial after vial with St. Martin’s secretions and dropped in all manner of foods. The cabin became a kind of gastric-juice dairy. Beaumont, in the painting, holds one end of a length of gum elastic tubing in St. Martin’s stomach; the other end drips into a bottle in Beaumon
t’s lap.

  I spent a good deal of time staring at this painting, trying to parse the relationship between the two. The gulf between their stations is clear. St. Martin wears dungarees worn through at the knees. Beaumont appears in full military dress—brass-buttoned jacket with gold epaulettes, piping-trimmed breeches tucked into knee-high leather boots. “True,” Cornwell seems to be saying, “it’s an unsavory situation for our man St. Martin, but look, just look, at the splendorous man he has the honor of serving.” (Presumably Cornwell took some liberties with the costuming in order to glorify his subject. Anyone who works with hydrochloric acid knows you don’t wear your dress clothes in the lab.)

  The emotions are hard to read. St. Martin appears neither happy nor aggrieved. He lies on his side, propped on an elbow. His posture and far-off stare suggest a man reclining by a campfire. Beaumont, admirably erect, sits in a buckskin chair by the bed. He stares into high middle distance, as though a TV set were mounted on the cabin wall. He looks like a hospital visitor who has run out of things to say. The prevailing mood of the painting is stoicism: one man enduring for the sake of science, the other for subsistence. Given the painting’s intent—the glorification of medicine (and Beaumont and Wyeth labs)—it’s fair to assume the emotional content has been given a whitewash. It can’t have been a hoot for either. At least once in his notes, Beaumont mentions St. Martin’s “anger and impatience.” The procedure was not merely tedious; it was physically unpleasant. The extraction of the gastric juices, Beaumont wrote, “is generally attended by that peculiar sensation at the pit of the stomach, termed sinking, with some degree of faintness, which renders it necessary to stop the operation.”

  The disrespect displayed by Beaumont and the medical establishment—evident in their correspondences about St. Martin—can’t have helped. St. Martin was referred to as “the boy” well into his thirties. He was “the human test tube,” “your patent digester.” For the out-of-body digestion experiments, Beaumont had St. Martin hold vials of gastric juice under his arms to simulate the temperature and movements of the stomach. “Kept in the axilla and frequently agitated for one hour and half,” Beaumont’s notes read. If you’d never heard the term axilla, you’d think it was a piece of laboratory equipment, not a French Canadian’s underarm. Beaumont carried out dozens of experiments that required St. Martin to hold vials this way for six, eight, eleven, even twenty-four (corn kernel!) hours. Not surprisingly, St. Martin twice quit—“absconded,” as Beaumont termed it—partly to see his family in Canada, but also because he’d had enough. Only the second time did he do so in violation of a signed contract, and for this he earned Beaumont’s lasting ire. In a letter to the U.S. surgeon general composed around that time, Beaumont deplores St. Martin’s “villainous obstinacy and ugliness.”

  But Beaumont had no other fistulous stomach to turn to. Though he’d finished his experiments, he needed St. Martin to bolster his status overseas. Late in his career, he’d come to know a group of scientists in Europe—chemists and others to whom he’d shipped* bottles of gastric juice for analysis. (His correspondence from that period is a mix of ghoulishness and high manners. “I thank you very much for your Bottle of the gastric fluid.” “I have . . . with peculiar pleasure experimented upon the masticated meat . . . , as suggested in your last letter.”) Though none of these men successfully identified the various “juices,” one had invited him to lecture in Europe, with St. Martin along as a kind of human PowerPoint.

  What ensued was a game of Coyote and Roadrunner that dragged on for more than a decade. Sixty letters went back and forth among Beaumont, St. Martin, and various contacts at the American Fur Company who had located St. Martin and tried to broker a return. It was a seller’s market with a fevered buyer. With each new round of communications—St. Martin holding out for more or making excuses, though always politely and with “love to your family”—Beaumont raised his offer: $250 a year, with an additional $50 to relocate the wife and five children (“his live stock,” as Beaumont at one point refers to them). Perhaps a government pension and a piece of land? His final plan was to offer St. Martin $500 a year if he’d leave his family behind, at which point Beaumont planned to unfurl some unspecified trickery: “When I get him alone again into my keeping I will take good care to control him as I please.” But St. Martin—beep, beep!—eluded his grasp.

  In the end, Beaumont died first. When a colleague, years later, set out to bag the fabled stomach for study and museum display, St. Martin’s survivors sent a cable that must have given pause to the telegraph operator: “Don’t come for autopsy, will be killed.”

  BY TODAY’S STANDARDS of political correctness, William Beaumont had an unattractive sense of entitlement and superiority. I don’t see this as a product of flawed morals. After all, this is a man who claimed, in his diary, to be following Benjamin Franklin’s “plan for attaining moral perfection.” I see it, rather, as a product of nineteenth-century class structure and the larval state of medical ethics. The medical establishment of the day didn’t concern itself greatly with issues of informed consent and the rights of human subjects. It wouldn’t have occurred to people back then to condemn William Beaumont for exploiting a “porkeater” to advance scientific knowledge or his own career. St. Martin was compensated, they’d point out; he was never held against his will. Beaumont was judged solely on his contributions and commitment to physiology. He was, and remains, a lauded figure in the history of medicine.

  More than anything else, the story of Beaumont and St. Martin is one of obsession. Here was a man who devoted his adult life and more than a thousand dollars of his own money to the study of gastric fluids. Here was a man willing, in the name of science, to taste chymified chicken from another man’s stomach (“bland and sweet”). A man who became, as his biographer Jesse Myer put it, “so deeply engrossed in his subject that it was difficult for him to understand why everyone could not feel the same interest.” Beaumont was crushed by the lackluster sales of his book, Experiments and Observations on the Gastric Juice, and the Physiology of Digestion, in the United States and the bald disinterest from British publishers. (“I have returned Beaumont’s Experiments, as I do not feel inclined to make an offer for it,” read one rejection letter in its chilly entirety.) Among the William Beaumont Papers at Becker Medical Library are letters from the doctor to the secretary of the navy and the secretary of war, urging them to purchase a hundred copies of his book. (The navy man, a bit of a softie, bought twelve.) Beaumont had friends in high places, and he sent every single one a signed copy. Picture Martin Van Buren, then the vice president of the United States, leaning back in his magnificent leather-upholstered desk chair and opening Beaumont’s book at random and reading, “At 9 o’clock A.M., I put a solid piece of rib bone, of an old hog, into a vial . . . of pure gastric juice, taken from the stomach this morning.” Ambassadors, chief justices, senators, and representatives, all were forced to take time away from their weighty lives to pen thank-you notes for a book on stomach secretions. (“Truly a work of most surpassing interest.” “I regret I have not yet been able to look into it with any attention.”)

  Obsession is a pair of blinders, and Beaumont wore his tightly. He far overstated the role of gastric acid, ignoring the digestive contributions of pepsin and of pancreatic enzymes introduced in the small intestine. As is regularly evidenced by tens of thousands of gastric reflux sufferers—their acid production pharmaceutically curtailed—humans can get by with very little gastric acid. The acid’s main duty, in fact, is to kill bacteria—a fact that never occurred to Beaumont. What, for all his decades of experimenting, did he teach us? That digestion is chemical, not mechanical—but European experimenters, using animals, had shown this to be true two centuries earlier. That protein is easier to digest than vegetable matter. That gastric juices don’t require the “vital forces” of the body. Not, in short, all that much.

  I have on my own bookshelf a 241-page book about saliva. It is a gift from the author, Erika Silletti, a
nd Silletti has signed it for me. She is surely as proud of her book as William Beaumont was of his, and she too endures the peculiar burden of the committed digestive scientist: the snipes and quizzical silences of people who can’t understand why anyone would want to do such a thing for a living; the disappointment of parents who had looked forward to bragging about their child’s career in surgery or neuroscience; the second dates that never materialize.

  Dr. Silletti was delighted to hear that I wanted to visit the saliva lab. People rarely ask to visit Erika Silletti’s lab. I am honestly curious about saliva, but I am also curious about obsession and its role in scientific inquiry. I think it’s fair to say that some degree of obsession is a requisite for good science, and certainly for scientific breakthrough. Had I been able to spend time with William Beaumont in his lab, I imagine that my initial negative impressions of him and his work—the unorthodoxy of his methods, the seeming insensitivity to St. Martin—would have fallen away, and in their place I would have felt a measure of respect for the inventiveness and dedication at the core of what he did. I would have pitied St. Martin, not because Beaumont treated him badly, but because life had—because the circumstances of his birth afforded no opportunity to be William Beaumont.

  Of course, there’s a good chance St. Martin was happier in his simple shack with his family, “perfectly necket,” than Beaumont was toiling in his labs, misunderstood by his colleagues. To each his own. Beaumont was a man for whom career came first. Like any experimenter, he was meticulous and exacting. People are messy, unpredictable things. Science you can control. Which is why St. Martin was such a bugbear for Beaumont.

  Here is what William Beaumont had to say about saliva: “Its legitimate and only use, in my opinion, is to lubricate the food to facilitate the passage of the bolus through the [esophagus].” Beaumont was right about some things, but he was dead wrong about spit.