May 2 - John Scott Haldane

while below the town, deep in the pit
a rock-fall struck a spark from steel, and fired
the void, punched through the mine a fist
of blazing firedamp.

- from Six Bells by Gillian Clarke

Today is the birthday in 1860 of John Scott Haldane, who somehow managed to survive until 1936 despite a lifetime of self-experimentation in the name of science. Haldane came from an affluent and well-connected Scottish family, receiving his medical degree from the University of Edinburgh.

In the introduction to his book Respiration, published in 1922, he wrote that this work was the product of a transition period.

The mechanistic theory of life is now outworn and must soon take its place in history as a passing phase in the development of biology. But physiology will not go back to the vitalism which was threatening to strangle it, and from which it escaped last century.

In his The Philosophical Basis of Biology, published in 1930, he beautifully expresses the reality that organisms and their environments are mutually adapted to each other, and cannot be fully understood through a mechanistic or reductionist approach. And further, that this did not make biology any less exact or scientific.

In so far as we discover co-ordinated maintenance we reach exactitude in biology.

Along with this philosophy, Haldane brought the practice of rigorous experimentation and data collection to his work. Returning to Respiration, Haldane explains:

It was only by human experiments that the almost incredible delicacy of the regulation of breathing was discovered: and human experiments have revealed to us in other ways how rough many of the experiments on animals, or on "preparations" from the bodies of animals, have been.

In 1887, while in his first position at University College, Dundee, Haldane published a study of the air quality in overcrowded, unventilated rooms in impoverished areas of Dundee. Apparently, he would arrive in the middle of the night and knock on doors, scientific apparatus in hand, to measure the levels of carbon dioxide, mold, and other impediments to healthy breathing in tiny rooms packed with formerly sleeping people. His studies showed that the air in these rooms was measurably dangerous, with noxious gases and bacteria at shockingly high concentrations.

Haldane's interest in good and bad air quickly brought him into a realm in which bad air turned spectacularly deadly with tragic regularity, coal mines. British coal powered the industrial revolution and it was mined at an almost unimaginable scale, and cost. In 1912, the year the Titanic sailed out, its luxury and speed powered by British coal, there were 1,117,148 men, women, and children employed in coal mines in the United Kingdom, that is over 2.5% of the country's population of around 44 million at the time, and that year 1,319 would die, close to the Titanic's loss of life of 1,500, and a fairly representative year for mining fatalities.

Miners' evocative terminology for the various dangers of "bad air" preserve the Germanic root "damp" in its general meaning of "vapor". Firedamp contained methane, and killed with obvious explosive violence. Various designs of safety lantern had been invented to give warning in the event of the presence of methane. Blackdamp, carbon dioxide, released by mining activity would silently smother its victims. Whitedamp would do the same, as the coal exposed to oxygen would smoulder and emit carbon monoxide. In the aftermath of a firedamp explosion, those miners not burned or killed by flying debris or a shockwave would often succumb to the mysterious afterdamp.

In 1896 Haldane was called in to investigate a mine explosion at Tylerstown Colliery in South Wales in which 57 men died. Over 90% of the fatalities were due to afterdamp, not the initial explosion. It was too late to obtain a useful air sample, so Haldane's determination that afterdamp's fatal effects were a result of carbon monoxide poisoning came from both an examination of those bodies obviously not killed by the initial explosion, and a careful quantitative estimate of the likely distribution of gases following an explosion. Unlike carbon dioxide suffocation, carbon monoxide poisoning took place while there was ample oxygen present, so dimming or flickering lanterns would not provide any warning to miners or would-be rescuers.

Haldane had built an airtight chamber in his office and would conduct experiments on himself, carefully noting the physiological effects of whatever combination of gases he was exposing himself to. One set of experiments involved simply rebreathing the same air, noting the increases in carbon dioxide and decreases in oxygen over time. After the mine investigation, he moved on to breathing carbon monoxide to observe its effects. He would often stagger home after these experiments, still feeling the effects of various gases, attracting the attention of policemen assuming he was drunk. On one occasion, an anxious neighbor with a missing cat enquired if Haldane hadn't put it to use in his experiments. He hadn't, but Haldane did study the effects on small animals of the gases he had been breathing.

Birds have powerful breathing capacity to allow them to fly and function at high altitudes, and are correspondingly sensitive to air pollution. When Haldane realized that Serinus canaria was affected 20 times faster than humans by carbon monoxide and other toxic gases, he manufactured a special cage which exposed a captive canary to outside air. If the canary collapsed, the miner would know to evacuate, after sealing the canary's jar and opening a small oxygen supply to save the bird's life. Canaries would remain in service in British coal mines until 1986, and the phrase "canary in the coal mine" will probably remain in service for as long as English is spoken.

Haldane also studied the impact of both high and low air pressure on breathing.

In 1911, he traveled to Pike's Peak in Colorado with researchers from Oxford, Yale, and Colorado College, which also provided local laboratory facilities. Pike's Peak is at an altitude of just over 14,000 feet and was serviced by the Manitou and Pike's Peak Railway, a tourist railway which had been financed by Zalmon Simmons, the founder of the Simmons Bedding Company, who was horrified that taking in the breathtaking views from the summit had required two miserable days traveling by mule. The Cog Railway is still active today, having reopened in May of 2021, its 130th anniversary. Thanks to the railway, Haldane's team enjoyed easy access and they and their laboratory equipment were accommodated in Summit House, then a restaurant with limited sleeping accommodations. The Railway also brought a steady supply of non-acclimated human subjects experiencing high altitude, who could be observed by the team. Their paper, published in Philosophical Transactions of the Royal Society, begins predictably enough with the team's graphic self-observations of the altitude sickness they suffered their first day, and then goes on to quite amusing descriptions of the unprepared and underdressed tourists spending their holiday collapsed miserably on the ground with altitude sickness instead of enjoying the sunrise view. You can still find unprepared and underdressed tourists in the Rocky Mountains, but these days, thanks to Haldane, they can pop into an oxygen therapy bar on just about every block.

Collaborating with the team, but in a different location, was Mabel Purefoy Fitzgerald. She traveled around Colorado collecting data on the long-term effects of living at high altitude from residents, work which was published in the same Philosophical Transactions of the Royal Society, communicated by J.S. Haldane since Miss Fitzgerald could not submit herself. Fitzgerald had been the first female medical student at the University of Oxford, in an unofficial capacity, and had an impressive research career until 1915, when she transitioned to teaching. Despite years of jumping through hoops in multiple countries, she was never granted a medical degree. Fitzgerald lived to be 101 years old, and was granted an honorary M.A. degree by Oxford when she was 100 years old, in 1972.

Haldane's work with high air pressure, such as that experienced when breathing pressurized air while diving, would lead directly to the development of decompression tables. Haldane's then 13 year old son, J.B.S. Haldane, would participate in many diving experiments and would go on to have his own scientific career, among other things proposing the concept of in vitro fertilization. Haldane's daughter, Naomi Mitchison, also conducted and participated in experiments as a child, but later found her fame in her fiction writing.

Haldane seems to have been a man whose scientific inclinations and capabilities perfectly fit the opportunities of the time. And while many of his experiments on human subjects, including exposing his own six-year-old son to chlorine gas, would be viewed with horror today, he did take great care with his subjects and sought to avoid unnecessary suffering wherever possible, even if he had no conception of informed consent.

Haldane's opus Respiration has little to say on the subject of singing, other than that it, along with speaking, interrupts the regularity of ordinary breathing. Alessandro Scarlatti, the father of Domenico Scarlatti, was a renowned operatic composer. Like Haldane, his work also formed part of a transition, in his case between the Baroque and Romantic styles of classical music. Alessandro Scarlatti was born 200 years to the day before Haldane, on May 2nd.