During the extreme violence and bombings of World War II, England called on its citizens to do what they could to help. That meant food rationing for everyone and long hours working in factories for some. For a small group of scientists in London, however, it meant putting their lives on the line while doing math—lots and lots of math, sometimes while drunk. This group helped make the Allied landings on D-Day possible.

John Burdon Sanderson Haldane, who went by JBS or simply “the Prof,” led a team of geneticists working out of a lab at University College London. Helen Spurway, his partner in life and in using mathematics to examine the inheritance patterns of salamanders, was the lab’s co-pilot. The two lived in the lab during the day and at the bar across the street at night.

When the evacuations of London began, followed by the bombings that developed into the infamous Blitz, the university tried to close its doors to force all of its people to safety. It tried, but Haldane and Spurway snuck their way in anyway. With their blackout curtains drawn firmly against the probing eyes of not only Nazi bombers but also administrative officials on the hunt for rebellious scientists, Haldane and Spurway began to recruit others who had stayed behind. Among them was Edwin Martin Case, a researcher from Haldane’s past who had already proved his brilliance and, by coming to the center of the Blitz, also proved his mettle.

Chamber Divers: The Untold Story of the D-Day Scientists Who Changed Special Operations Forever

The previously classified story of the eccentric researchers who invented cutting-edge underwater science to lead the Allies to D-Day victory

When the Allies’ submarines started going down in alarming fashion—the American USS Squalus, the British HMS Thetis and the French Phénix, all within three weeks of each other in the summer of 1939, and all in training accidents—they were forced to realize they had no idea what they were doing underwater. But Haldane did. He and his team of downtown rebels had started studying the physiology with the most easily scheduled test subjects they could find: themselves. By 1940, the experiments were full speed ahead.

On Friday, April 19, Case, hunched into a sphere, balanced a steel ball bearing precariously on a toylike scoop. He was determined to transfer the ball bearing into the correct hole. With a solid plunk, the metal sphere found its home just before the single minute allotted for the task ran out. Dropping the fiddly scoop, Martin began to pick up the bearings with his fingers instead. That way was much easier.

Case was curled inside the smallest hyperbaric chamber at Siebe Gorman, a British diving equipment manufacturer, for the fourth day of testing. He passed the “ball game” sideways to Haldane, who was also bent over by the white tubular walls. The already small space was constrained further by equipment, pads of paper, stopwatches and two breathing apparatuses for use on the way back up. This particular chamber contained no lights, because it could go deep enough that electricity might spark a catastrophic internal fireball. The duo had some small portable electric lamps inside, but most of their vision was extracted from meager bulbs pressed from the outside against the tiny portholes of the darkened tube.

The HMS Thunderbolt
The HMS Thetis was salvaged, repaired and recommissioned as the HMS Thunderbolt (pictured here). Public domain via Wikimedia Commons

Haldane began his first minute of the ball bearing test of manual dexterity, shaking off a lingering headache caused by the previous day’s exposure to fully oxygenated air. He deposited the bearings in the holes using forceps. He and Case began the arithmetic next—mental dexterity, as it were. Haldane went first while Case timed him.

After generating sheets of numbers scrawled in rapid, curling streaks of pencil, they heaved the burly, circular chamber door closed around its pivot of heavy steel hinges, swinging its domed shape into contact with the main body of the steel tube. Now, with the door shut, the carbon dioxide would begin to accumulate inside, just as it had inside the Thetis. Air began to intrude through the piping, first with a hiss, then with a roar. The very real physical heat enveloping Case and Haldane began to climb, in an unsubtle metaphor for the rising pressure from the military to achieve results.

The first thing on their checklist, and the subject of today’s work, was an explicit request from the Admiralty. Surgeon Commander Seymour Grome Rainsford wanted more information about nitrogen narcosis, the recently developed theory that nitrogen might become a powerful, even debilitating narcotic drug under increased pressures—a tendency that, if true, would affect anyone trying to perform complex tasks like espionage or escaping from a submarine deep underwater.

JBS Haldane in 1939
JBS Haldane in 1939 Bettmann via Getty Images

Divers had always reported euphoria and a sense of mental stupor at the limits of diving’s deepest depths, but the American physician Albert Behnke had just declared the nitrogen in their breathing air to be the cause. Rainsford wanted to know if Behnke was right. Haldane used the request to get the government to pony up a modest salary for Case: “I should be glad to carry out and supervise experiments on the problem and should not demand any salary. However, I should require an assistant.”

In this small tube, Haldane and Case would breathe air, which is 78 percent nitrogen, and see if the gas interfered with their ability to manipulate the ball bearings or affected the time and accuracy with which they could complete the written math. In short, they would see if nitrogen got them properly drunk.

Today, nitrogen narcosis is known to be an immutable effect of breathing air under pressure. Divers often affectionately refer to the phenomenon as “Martini’s law,” meaning that each 33 feet below the surface of the ocean can be considered equal in mental deficit to pounding down one martini with gusto. Perhaps given the time and place of Haldane and Case’s experiment, a sidecar with a twist would have been a more appropriate drink metaphor. But regardless of the beverage, inside less than four minutes, with the internal chamber air screaming hot from the compression, Haldane and Case reached 300 feet of seawater, which would allegedly have had the same impact as imbibing nine glasses of straight booze, in less time than it might have taken to drink the actual liquid.

How Does a HYPERBARIC Chamber Work?

As of this writing, nobody yet understands why nitrogen narcosis occurs. But it certainly does. Case and his old pal were smashed.

Case tried to be modest about it. “Slight feeling akin to what one has always been led to believe is associated with inebriation,” the chemist scribbled, coyly selecting words as if he hadn’t once been cited for piloting his bicycle with such liquid-fueled abandon that he posed a public health hazard.

Haldane wrote notes, too, or at least tried to. He couldn’t write as coherently. “Reach top. MC says, ‘We are drunk.’ Notices above. Not so [illegible scribble]. JBSH feels abnormal. ‘Ringing’ in ears. Queer taste in mouth. Looks darker (?) [illegible].”

They were inside a tube, so there was no “above” to be had. The statement was gibberish. Pressure doesn’t cause ear ringing or weird mouth tastes, so those were imagined. Even later, neither Haldane nor anybody else in the lab could read some of the words or discern what “darker” was supposed to refer to. Haldane would also say that he had “felt somewhat mystical.” In short, the narcosis was winning.

Martin Case as a young man
Edwin Martin Case as a young man Courtesy of Christine Love
Aerial view of D-Day landings
Aerial view of D-Day landings U.S. Air Force

Haldane and Case tried the ball game, followed by the arithmetic problems, but the test results were moot because they both kept forgetting to start the stopwatch. Haldane blamed his distraction on the “sound of bell ringing.” There was no bell.

When Haldane tried the sums, he began mixing up the sheets of paper or starting a problem in one column but continuing it in the next. When Case noticed how long Haldane was taking with the rudimentary addition and asked how much longer he needed, the math genius grumbled, “I don’t know at all, nor do I care.” After incomplete attempts at forcing the numbers, he wrote down, “Feel better,” as if he were a credible witness to his own condition.

They had reached 300 feet at 12:10 p.m. By 1:10 p.m., they had struggled long enough. They put the mouthpieces from the breathing apparatuses into their mouths and began breathing pure oxygen before the ascent. By removing the nitrogen from the gas they were inhaling and using pure oxygen instead, they could increase the rate at which their bodies dumped the stored nitrogen out of their tissues. They could reach the surface faster, with less time spent decom‑ pressing and less risk of decompression sickness. Later, Haldane would have no memory of a small repair he had made to a pipe connection before donning his mouthpiece.

As they reached the surface, Haldane felt a searing pain in his mouth and heard an audible screaming sound emanating from inside one of his teeth. He’d had a cavity filled in an upper incisor as a child, but the dentist obviously hadn’t completely filled the hole. The sound was pressurized gas slowly squeaking out of the former cavity. It hurt like hell, but to Haldane, it was all good data. He cheerfully reported, “I believe [the toothache] is a new type of bends.” He promptly had the tooth removed to facilitate future tests.

After many more tests, the duo’s conclusion was the same as Behnke’s: Yes, the narcosis was real. It was caused by nitrogen. They had achieved their first task on behalf of Britain. Haldane and Case wrote of nitrogen narcosis that “it is quite imperative that no great trust should be placed in human intelligence under these circumstances.” It was an understatement.

The first month of testing crept toward May, and the experiments continued smoothly and without calamity. On day one, Haldane and Case had sat upright inside the largest chamber and breathed oxygen and played the ball game at shallower depths, with both subjects developing no more than a mysterious slight cough afterward. On day two, the fit young Case had donned some of Haldane’s extra-large clothing and shoes and clambered into a water tub inside the chamber, with water that was 50 degrees Fahrenheit and large blocks of ice chained to the bottom. He let his exhaled CO2 build up around him to simulate a submariner in a cold, Atlantic-flooded compartment. Government representatives milled around the safe, warm outside of the chamber, muttering observations, until Case crawled out, hypothermic, shaking too hard to complete the manual dexterity test but ready for his rectal temperature measurement.

Frogmen of the LCOCU leave the water after completing their task.
British frogmen, or trained scuba divers, leave the water after completing their task in 1945. Imperial War Museum under IWM Non Commercial License / © IWM (A 28997)

In the context of the world of science, a little coughing and a little limb shaking weren’t considered much of a big deal. The scientists were chipping away at the first set of problems, seeing how long they could withstand CO2 and the cold, and getting a feeling for how long submariners inside a doomed vessel had before they became too incapacitated to help themselves.

Other self-experimenters had put themselves through worse for less. Around the turn of the 19th century, Sir Humphry Davy knocked himself unconscious during repeated testings of his first nitrous oxide mixtures. In the 1910s, epidemiologist Joseph Goldberger was determined to prove that pellagra, a disease now known to be caused by severe vitamin B deficiency, was not caused by infectious pathogens. His method of proof, naturally, was to hold gatherings he called “filth parties,” where he and his scientist friends would eat capsules filled with the scabs and scrapings of pellagra victims. None got infected.

Articles from the Times of London in the 1920s and 1930s indicate that self-experimentation was considered fairly normal in the era—perhaps not common, but certainly somewhere on the list of the zaniness expected from those who played with test tubes and loved tweed. Scientists were still considered hobbyists, in a way. Science was relatively new as an independent field; its roots were as an activity practiced by middle- or upper-class people at home in their spare time after their real day’s work as barons, doctors, lawyers or whatever professions left them enough free time and resources to putter.

Humphry Davy
Humphry Davy Public domain via Wikimedia Commons
Joseph Goldberger
Joseph Goldberger Public domain via Wikimedia Commons

The notion of self-experimentation popped up mostly in obituaries describing the lives of such people, usually as stray sentences thrown into otherwise eulogizing articles with the literary equivalent of an affectionate chuckle over their strange hobbies. In 1939, the Royal Institution in London even hosted a Christmas lecture to entertain children with the story of Davy’s self-anesthetizing adventures.

The self-experiments were anything but zany to the scientists. With little formal legal structure in place to provide ethical guidance for human experiments, researchers often saw their own bodies as the easiest way—or the only way—to get data. Sometimes the tests were lethal. In 1938, around the same time as the high-spirited children’s lecture, the latest in a long list of doctors died during self-trials with anesthesia.

The noble practice also sometimes was—and still is—used as a loophole by charlatans. In that same decade, another “scientist” was put on trial for fraud. In his defense testimony, he bellowed that his “miracle cure” had allegedly fixed his own medical issues, so of course he should have been allowed to market and sell it at high prices without further question. His medical license was revoked, but the same infamous claim of “It worked for me” is still often used today as a dodge by those who wish to avoid regulatory scrutiny. It lets them peddle their “cures” without actual proof, because they’re technically not making promises that it will work for anyone else. All good tests need proof from other people.

When World War II started, the need for results drove volunteerism for science. Many who could not sign up for the military for reasons ranging from religion to physical condition signed up to support their country through experiments instead. Dozens in England volunteered to be infected with painful, itching scabies to test better treatments, because the wars of the past warned that the ailment would soon blaze through the troops abroad. One man named Horace Cameron Wright started plotting out the holes in the Allies’ understanding of lung injuries from underwater explosions. He realized that the only way to fill those holes was to volunteer to get blasted.

German soldiers marching through Oslo on the first day of their invasion of Norway in April 1940
German soldiers marching through Oslo on the first day of their invasion of Norway in April 1940 Public domain via Wikimedia Commons

In the United States, pacifist Quakers signed up for voluntary starvation after early intelligence indicated that somewhere in Germany, there were people who might benefit from knowledge of the safest way to reintroduce food when starved to the brink of death. And Haldane loudly offered to climb inside and personally test better air raid shelters to protect the people of London once the threat of bombing loomed its ugly head—in addition, of course, to the work he was conducting in the pressure chambers. The knowledge of the world moved forward.

German forces had attacked Denmark on April 9, 1940. Denmark surrendered on the day of the attack, but Norway struggled against the invasion into June. The Norwegians did their part to fight the Nazis on land while Haldane and Case itched to do theirs at sea.

From Chamber Divers: The Untold Story of the D-Day Scientists Who Changed Special Operations Forever by Rachel Lance, with permission from Dutton, an imprint of the Penguin Publishing Group, a division of Penguin Random House, LLC. Copyright © 2024 by Rachel Lance.

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