The History of Canaries in Coal Mines

The use of canaries in coal mines began in the late 19th century as a biological early-warning system to protect miners from toxic, odorless gases like carbon monoxide and methane. Proposed by British scientist John Scott Haldane in 1895, the practice became a legal requirement in countries like the UK, the US, and Canada through the mid-20th century. It officially ended in December 1986 when digital gas detectors replaced the birds.

Before the 1890s, miners relied on primitive methods to test air quality. They used candles or safety lamps; if the flame shrank or went out, oxygen was low. If it flared up or turned blue, flammable methane gas (“firedamp”) was present.

The fatal flaw in this system was carbon monoxide (CO), or “afterdamp.” Formed after mine fires or explosions, CO is completely invisible, odorless, and highly toxic. A candle flame burns perfectly normal in carbon monoxide, meaning miners would walk directly into a lethal pocket of gas without warning.

Enter John Scott Haldane, a brilliant Scottish physician and physiologist (later known as the “Father of Oxygen Therapy”). Following a devastating mine explosion at Tylorstown Colliery in Wales in 1896, Haldane investigated the disaster and proved that the vast majority of the casualties weren’t killed by the blast itself, but by carbon monoxide poisoning afterward.  Haldane began experimenting with different animals to find a biological sentinel that was more sensitive to air quality than humans. After testing mice, rabbits, and various birds, he discovered the ideal candidate: the canary. 

Canaries possess a unique respiratory anatomy that made them flawless biological radar. To sustain flight and survive at high altitudes, canaries require immense amounts of oxygen.

Unlike humans, a bird’s respiratory system uses an intricate system of air sacs. When a canary inhales, it takes in air; when it exhales, it pushes air from its sacs into its lungs. This means it receives a double dose of oxygen, and a double dose of any airborne poisons, with every breath cycle. Because of their tiny size and fast metabolism, a canary absorbs carbon monoxide roughly 20 times faster than a human.

In a gas-laden tunnel, a canary would show visible signs of distress—agitating, stopping its song, and ultimately falling off its perch unconscious—up to 20 minutes before a human would feel a single symptom. This gave miners a critical window of time to evacuate.

A common misconception is that canaries were treated as disposable, tragic sacrifices. In reality, miners grew deeply attached to their avian companions. They kept them at the pit tops, treated them like pets, and constantly whistled and spoke to them underground.

To protect the birds, Haldane designed a highly sophisticated piece of equipment: the canary resuscitator cage. The cage featured heavy glass walls with an open, grated front door to let the mine air circulate. The moment the canary succumbed to gas and fell from its perch, a miner would slam the airtight door shut and crack open a valve on the small oxygen cylinder mounted to the top of the cage. Within seconds, the chamber would flood with pure oxygen, reviving the canary as the miners carried it to safety. The exact same bird could go back to work the next day.

The practice was formally adopted in British legislation in 1911 and quickly spread to Canada and the United States (though some regions, like the American West, occasionally used wild mice instead due to availability). The birds stayed on the job long into the high-tech era. It wasn’t until December 1986 that the British National Coal Board officially phased out the final 200 pit canaries, replacing them with handheld digital gas detectors colloquially known as “electronic noses.”

Even after they were retired, many mining communities maintained aviaries near the colliery offices as a permanent tribute to the little yellow birds that had saved thousands of lives.

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French Children Were Served Wine at School on Their Lunch Breaks, All the Way Up Until 1956

In 1956, the French government officially banned the serving of wine, beer, and cider in school cafeterias to children under the age of 14. Prior to this ban, it was common practice for French schoolchildren to be served these beverages during lunch, with some reports indicating they were entitled to up to half a liter a day.

Wine was considered a nutritional staple rather than a vice. It was believed to aid digestion, provide energy, and strengthen” young bodies.

During the early 20th century, alcohol was thought to have antibacterial properties that could kill microbes and prevent colds. In areas where clean drinking water was scarce, diluted wine was often seen as a safer alternative.

Many parents encouraged the practice, sometimes even sending their children to school with their own bottles of wine or cider in their lunch baskets.

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Tsar Nicholas II’s Daughters Proudly Showing Their Bald Heads in 1917

During World War I, the four daughters of Tsar Nicholas II — Olga, Tatiana, Maria, and Anastasia — contracted measles in early 1917, which caused them to lose their hair. They shaved their heads as a practical response to the hair loss caused by the illness.

This happened during an already tumultuous time: the family was under enormous strain as the war dragged on and revolutionary pressure mounted in Russia. The girls were photographed bald, and these images became some of the more striking personal records of the Romanov family in their final years.

It was a fairly common practice at the time to shave the head when recovering from illnesses like measles or typhus, as it made caring for the patient easier and avoided the patchy, uneven hair loss that the fever caused. The photographs, taken by their French tutor Pierre Gilliard, show the princesses looking quite cheerful despite everything. In his diary, Gilliard noted that the sisters typically wore scarves to hide their heads, but on this day, they playfully whipped them off at a signal from Olga to surprise him and their parents.

By the time the family was executed in July 1918, their hair had grown back to roughly shoulder length.

Sharing a Cigarette During the Tour de France, ca. 1927

During the Tour de France in 1927, a captivating moment was captured as two cyclists shared a cigarette amidst the grueling race. At a time when the race was known for its extreme physical endurance and challenging terrain, the image of these athletes casually taking a break to smoke highlighted a stark contrast to the modern image of sports professionalism. Back then, cyclists were not the well-conditioned, highly trained athletes we think of today, but often worked with fewer resources and a less scientific approach to training.

The cigarette break served as a small, humanizing moment in the midst of the grueling competition. The riders, caught between moments of exhaustion and the fleeting respite, were sharing a brief pause from the intense race. The casualness with which they lit up during such an intense event shows how much the culture of competitive sports has changed over the years, with the focus now on optimal health and performance.

This iconic photograph from the 1927 Tour de France is a reminder of the past and how far the sport has evolved. It symbolizes a different era in cycling, one where athletes could share a smoke as easily as they shared the road. Today, the Tour de France is synonymous with elite athleticism, but this picture offers a rare glimpse into a time when the race was less about perfection and more about sheer will and grit, with moments of levity in between the fierce competition.

The “Death Diary” of Renowned Herpetologist Karl P. Schmidt in 1957

In 1957, renowned herpetologist Karl P. Schmidt documented his own death in a meticulous scientific account that newspapers later dubbed his “death diary.” After being bitten by a juvenile boomslang (Dispholidus typus), he refused medical treatment, choosing instead to record the clinical progression of the venom's effects until he lost consciousness.

On September 25, 1957, while identifying a 30-inch snake at the Chicago Natural History Museum (now the Field Museum), the snake bit Schmidt on the fleshy part of his left thumb. Schmidt wrongly believed a juvenile, rear-fanged snake could not deliver a lethal dose to a human. When colleagues urged him to seek help, he reportedly replied that medical intervention would “interfere with the symptoms” he was observing.

“I took it from Dr. Robert Inger without thinking of any precaution, and it promptly bit me on the fleshy lateral aspect of the first joint of the left thumb,” Schmidt wrote in his journal. 

Over the next day, he documented a terrifying sequence of symptoms: nausea, chills, gum bleeding, fever, and urination of blood. He maintained his routine, eating meals and taking the train home while recording every detail with meticulous precision. Even his breakfast the following morning was logged, complete with a note about continued bleeding from his mouth and nose, which he understated as “not excessive”—a chilling understatement, as it would be the last word he ever wrote.

September 25, afternoon: He noted the bite, described the snake, and recorded early mild symptoms before taking the train home.

September 26, 6:30 AM: He ate cereal, poached eggs on toast, applesauce, and coffee for breakfast, and noted continuous bleeding from the mouth and nose, though “not excessively.” “Excessively” was the last word Schmidt wrote.

After lunch, he vomited, called his wife, and soon became unresponsive. Despite attempts to revive him, Schmidt was pronounced dead at 3 PM. Schmidt was advised to seek medical help just hours before he died, but refused, saying “No, that would upset the symptoms.”

Boomslang venom causes disseminated intravascular coagulation, a condition in which so many small clots form in the blood that the victim loses the ability to clot further and bleeds to death. Schmidt’s autopsy revealed extensive internal bleeding. When he was brought into the hospital, he was bleeding from his eyes, lungs, kidneys, heart, and brain.

Boomslang antivenom is monovalent, it only works for boomslangs, and it certainly was not available in Chicago in the 1950s. However, in 2017, venom researchers tested a modern antivenom similar to what would have been available to Schmidt at the time and found it did a decent job neutralizing several deadly proteins in the boomslang venom. They noted that reducing the activity of a venom by even 25 percent can mean the difference between life and death.

Schmidt’s death raised awareness of the potential toxicity of rear-fanged colubrid snakes to the scientific community, resulting in a number of important studies in the 1960s and 1970s. His meticulous final diary remains one of the most extraordinary first-person scientific documents ever recorded — a scientist, true to his calling, observing nature even as it killed him.

The Dangers of the Baby Feeding Bottles in the Victorian Era

Patented around 1879–1880, these glass or earthenware “banjo” shaped bottles allowed babies to self-feed. Many had sweet sounding names such as “My Little Pet” and “Mummies Darling” while others were very nationalistic like “The Empire,” “The National” or “The Victorian.” Some simply advertised the chemist from which they were bought but many cashed in on the popularity of the Princess of Wales in the 1880s. Hence the most common inscriptions bore the words, “The Princess” or “The Alexandria.” However these sweet sounding names often belayed the hidden dangers of these little inconspicuous bottles. The later day nicknames “The Killer” or the “The Murderer” was indeed more apt.

The bottles were appealing to mothers as they allowed for more independence and encouraged children to feed themselves. Unfortunately, the slanted shape made the bottle very hard to clean. The rubber stopper and tubing absorbed bacteria delivering it straight into very vulnerable individuals. To make matters worse, the popular figure Mrs. Isabella Beeton outlined dangerous recommendations for nursing bottles in her publication, The Book of Household Management (1861).

“The prepared teats can be obtained at any chemist’s, and… they will require a little soaking in warm water, and gentle washing, before being tied securely, by means of fine twine... When once properly adjusted, the nipple need never be removed till replaced by a new one, which will hardly be necessary oftener than once a fortnight [14 days], though with care one will last for several weeks.”

The design and materials of the bottles, along with inadequate cleaning and care recommendations, led to the nickname “murder bottle.”

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In the 1950s, Hospital Patients Can Buy Cigarettes Right From Their Beds

In the 1950s, selling cigarettes in hospitals was a routine, accepted practice, with staff often wheeling carts directly to patient bedsides to sell packs or cartons alongside snacks and magazines. Smoking was widely allowed in hospital rooms, waiting areas, and nurses’ stations, as tobacco was not yet widely recognized as a major health risk.

Patients could purchase cigarettes from carts without leaving their beds. Smoking was common in hospitals, with some doctors even permitting or recommending it, mistakenly believing it could soothe patients. Popular unfiltered brands like Camels, Lucky Strike, Chesterfield, and Philip Morris were common.

Nurses and doctors often smoked in nursing stations, during reports, and while on duty. This practice reflects a period when tobacco was integrated into daily life and, in some cases, marketed as a health aid. This era preceded the widespread awareness of the dangers of smoking and the subsequent Surgeon General’s warnings.

Paul Karason, a Man Made Famous After His Skin Turned Permanently Blue in the 1990s

Paul Karason, famously known as the “Blue Man” or “Papa Smurf,” began his transformation in the early to mid-1990s due to self-medication with colloidal silver.

In the early 1990s, Karason was fair-skinned and freckled. Seeking a cure for various ailments, including chronic sinusitis, dermatitis, and acid reflux, he began consuming homemade colloidal silver. Using a battery-powered device, he brewed a solution of silver particles suspended in water. He drank approximately 10 ounces of this liquid daily and also applied a silver-based preparation topically to his face.

Over several years, the silver particles accumulated in his body tissues. When exposed to light, these silver deposits underwent a chemical reaction similar to photography, permanently turning his skin a deep bluish-gray.

Karason claimed he did not realize his skin had changed color until an old friend visited in the late 1990s and asked what he had on his face, thinking it was “camouflage makeup.” While the condition developed in the 1990s, he remained a recluse for years. He gained international fame in 2008 after appearing on the Today show and The Oprah Winfrey Show to discuss his condition.

Paul Karason died in 2013 at the age of 62. His death was caused by a heart attack that led to pneumonia and a severe stroke, which doctors stated was unrelated to his blue skin.

The Tragedy Story of Mary Mallon, aka “Typhoid Mary”

Mary Mallon (1869–1938), better known as Typhoid Mary, was the first person in the United States identified as an asymptomatic carrier of typhoid fever. An Irish immigrant and talented cook, she spent nearly three decades in forced isolation after being linked to multiple deadly outbreaks of the disease.

Mallon (foreground) in a hospital bed in 1909.

Born in Ireland in 1869, Mary Mallon immigrated to the United States in 1883. She was a talented cook for wealthy families in New York, a profession she took great pride in. Between 1900 and 1907, she worked for several households; in almost every one, family members and staff fell ill with typhoid fever shortly after her arrival. What made Mallon unique was that she never showed symptoms. While her employers suffered from high fevers and delirium, Mallon appeared perfectly healthy.

In 1906, after an outbreak in a vacation home in Oyster Bay, Long Island, a sanitary engineer named George Soper was hired to find the source. Soper eventually linked the various outbreaks to one common denominator: the cook.

Soper famously deduced that Mallon’s peach ice cream was likely the culprit. Because the dessert was made with raw fruit and not heated, the bacteria she carried (Salmonella typhi) remained alive and was passed to those who ate it. When Soper finally confronted Mallon, she was outraged. To her, a woman who had never been sick, the idea that she was a “walking germ factory” seemed like a malicious lie or a religious persecution.

Poster depiction of “Typhoid Mary” (1909).

Mallon did not go quietly. When health officials and police arrived to take her for testing, she reportedly fought them off with a carving fork and had to be physically restrained. Tests eventually confirmed she was shedding massive amounts of typhoid bacteria from her gallbladder.

Mallon was forcibly quarantined on North Brother Island in the East River for three years (1907–1910). She was eventually released by a new health commissioner under one strict condition: she must never work as a cook again. However, she struggled with the low wages of laundry work and remained unconvinced of her “carrier” status. She disappeared from the authorities’ radar and returned to cooking under the alias “Mary Brown.” In 1915, she caused a major outbreak at Sloane Maternity Hospital in Manhattan, infecting 25 people and killing two.

Mary Mallon, better known as Typhoid Mary, sits fourth from right among a group of inmates quarantined on an isolated island on the Long Island Sound.

After the hospital outbreak, public sympathy for Mary evaporated. She was returned to North Brother Island, where she remained in forced isolation for the rest of her life, another 23 years. She was quite active until 1932, when she suffered a stroke; afterwards, she was confined to the hospital. She never completely recovered, and half of her body remained paralyzed.

On November 11, 1938, she died of pneumonia at age 69. Mallon’s body was cremated, and her ashes were buried in at Saint Raymond’s Cemetery in the Bronx. Nine people attended the funeral. Some sources claim that an autopsy found evidence of live typhoid bacteria in Mallon’s gallbladder. Soper wrote, however, that there was no autopsy, a claim cited by other researchers to assert a conspiracy to calm public opinion after her death.

Angus Barbieri, the Man Who Fasted for 382 Days and Lost 276 Pounds (125 Kg) in the 1960s

Angus Barbieri was a Scottish man who fasted for 382 days, from June 14, 1965 to June 30, 1966. He subsisted on tea, coffee, sparkling water, vitamins and yeast extract while living at home in Tayport, Scotland, frequently visiting Maryfield Hospital for medical evaluation. Barbieri went from 456 pounds (207 kg) to 180 pounds (82 kg), losing 276 pounds (125 kg) and setting a record for the length of a fast.

Agostino “Angus” Barbieri was born in Tayport, Scotland to Italian parents who ran a fish and chip shop. Due to his weight, he often required assistance with ordinary tasks.

In 1965, at the age of 27, Barbieri checked into the Maryfield Hospital in Dundee. Initially only a short fast was planned, as the doctors believed short fasts were preferable to longer ones. Barbieri insisted on continuing because “he adapted so well and was eager to reach his ’ideal’ weight.” To avoid temptation, he quit working at his father’s fish and chips shop, which closed down during the fast. As the fast progressed, he lost all desire for food. For 382 days, from June 14, 1965 through June 30, 1966, he consumed only vitamins, electrolytes, an unspecified amount of yeast (a source of all essential amino acids) and zero-calorie beverages such as tea, coffee, and sparkling water, although he occasionally added milk and/or sugar to the beverages, especially during the final weeks of the fast.

Barbieri began his treatment in the hospital but for most of the 382 days lived at home, visiting the hospital for outpatient checkups, including blood and urine samples. Stool samples were not taken but he reportedly went up to 48 days between stools. His starting weight was recorded at 456 pounds (207 kg) and the fast officially stopped on July 1, 1966 when Barbieri had reached his goal weight of 180 pounds (82 kg). For the next ten days, the doctors placed him on a diet of salt and then sugar in preparation for solid food. Thus, some sources record the fast as being 392 days instead of 382.

After 1 year and 26 days without food, Angus Barbieri ate his first solid meal at 10 AM on July 11, 1966: a boiled egg and a slice of buttered bread. He said to the gathered newspaper reporters and photographers, “I have forgotten what food tasted like ... It went down OK. I feel a bit full but I thoroughly enjoyed it.”

In the 1971 edition of The Guinness Book of Records, Barbieri’s 382-day fast was recognized as the longest recorded. As of 2026, Barbieri retains the record for the longest fast without solid food. Guinness does not actively encourage records relating to fasting for fear of encouraging unsafe behavior.

Doctors were amazed by Barbieri’s ability to resist the temptation to eat without having to stay in the hospital. He celebrated his achievement by going on a vacation in Spain for three weeks, and a 1973 study found that Barbieri maintained a healthy weight of 196 pounds (89 kg),  concluding that “prolonged fasting in this patient had no ill-effects.” He moved to Warwick, married a woman named Mary, and had two sons. Barbieri died in September 1990 after a short illness.

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In 1948, Mr. Cig, the Mascot, Handed Out Free Cigarettes to Patients at Hospitals in England

In the 1940s, a promotional campaign featured a human-sized cigarette mascot known as “Mr. Cig” or “Mr. Cigarette” who visited hospital patients. During this era, tobacco companies, including Philip Morris and Camel, distributed free cigarettes and promotional materials to patients in an effort to normalize smoking and associate it with positive concepts like glamour and recovery. These visits occurred when smoking was widely accepted and even seen as a way to calm nerves or help with stress, long before the link between smoking and health issues was fully understood and publicized.

This practice declined after the 1960s as scientific evidence mounted, showing the harmful effects of smoking, leading to major public health campaigns against smoking and its ban in many places.

Before Commercial Airplanes Were Pressurized, Passengers Required Oxygen Masks at High Altitudes

Before pressurized cabins changed aviation forever, flying high was a serious and risky business. In the 1930s, commercial aircraft reaching altitudes of 10,000–12,000 feet (about 3,000–3,600 meters) didn’t have the technology to maintain breathable air pressure inside the cabin. So how did passengers survive the thin air? They wore bulky oxygen masks for the entire flight, and yes, it looked as dramatic as it sounds.

In the 1930s and early 1940s, cabins were not sealed or pressurized, so flying above 10,000–12,000 feet meant passengers and crew were exposed to dangerously thin air and low oxygen levels (hypoxia). Photos at the time show passengers wearing prominent, often bulky, face masks made of rubber or fabric. They resembled early military aviation masks more than the small, modern emergency masks. These were connected via a tube to an onboard, manual oxygen supply system. Oxygen usually flowed continuously, which could be inefficient and contribute to frost accumulation in cold cabins.

A major innovation in the late 1930s was the Boothby-Lovelace-Bulbulian (BLB) mask, developed at the Mayo Clinic in 1938. This was a more effective oronasal (covering both nose and mouth) mask design that reduced oxygen waste and was quickly adopted by the military and airlines. It was more comfortable and reliable than earlier “pipe-stem” devices or ill-fitting masks.

Oxygen mask technology improved significantly during World War II, with advancements like the A-14 mask (an enhancement of the BLB mask) that incorporated automatic diluter-demand systems for more efficient oxygen use, primarily for military pilots.

The early 1940s marked a pivotal transition with the introduction of the first commercial airliners featuring pressurized cabins, such as the Boeing 307 Stratoliner in 1940. This technological leap allowed aircraft to maintain a comfortable, near-sea-level cabin environment at high altitudes, making routine oxygen mask use obsolete for passengers.

The need for passengers to routinely wear oxygen masks disappeared as pressurized airliners became more common. Oxygen masks transitioned from standard equipment to the emergency backup systems we know today, used only in the event of a sudden loss of cabin pressure.

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In the Late and Early 20th Centuries, Hospitals Often Featured Sun Decks Where Patients Could Bask in Natural Sunlight

Old hospitals, especially those built from the late 19th century through the mid-20th century, often had sun decks, rooftop terraces, or open verandas because of the then-prevailing belief in the healing power of sunlight and fresh air.

Before antibiotics and advanced medical treatments, sunlight therapy (heliotherapy) was widely believed to help patients recover from a range of illnesses — especially tuberculosis, pneumonia, and skin diseases. Doctors thought that exposure to sunlight could kill germs, strengthen the body, and improve mood. Hospitals often placed beds and reclining chairs on sun decks so patients could rest outdoors daily.

In the late 19th and early 20th centuries, medical architecture emphasized fresh air circulation to reduce infection and “stale air” — thought to spread disease. Sanatoriums for TB patients were often built in mountains or seaside areas, with wide balconies and open porches. General hospitals copied this design, incorporating open-air wards or roof gardens.

Architects and doctors worked together to design hospitals that were bright, airy, and uplifting — a reaction against the dark, crowded hospitals of earlier times. You’ll see sun decks on hospitals built between the 1900s and the 1940s, often with south-facing terraces for maximum sunlight. This was part of the “pavilion plan” — separating wards to improve airflow and prevent cross-infection.

By the 1950s–60s, antibiotics, air conditioning, and modern infection control made sun decks less necessary. Hospitals moved toward enclosed, climate-controlled designs, prioritizing equipment and efficiency over open-air recovery spaces.