The history
2,000 years from ‘breath of life’ to pulse oximeters, ventilators and the fight for clean air.
For most of history people knew that breath meant life, but not why. Thinkers in India, China and Greece called it prana, qi or pneuma. Over centuries, doctors traced blood through the lungs, chemists found oxygen, and physiologists learned how it slips into the blood. In the last hundred years machines have learned to breathe for us, babies have been saved by a soapy lining, and the air itself has become a health issue for billions.
c. 1242
Correct description of blood flowing through the lungs
Ibn al-Nafis, Egypt
1667
Animal kept alive by pumping air into its lungs
Robert Hooke, England
c. 1771–1774
Oxygen made in a lab
Carl Wilhelm Scheele, Sweden, and Joseph Priestley, England
1816
Stethoscope
René Laennec, France
1846
Spirometer and ‘vital capacity’
John Hutchinson, England
1928
Iron lung used on a patient
Philip Drinker and Louis Agassiz Shaw, USA
1953
Intensive care unit (widely credited)
Bjørn Ibsen, Denmark
1975
Pulse oximeter on sale
Takuo Aoyagi and Nihon Kohden, Japan
1983
Long-term successful lung transplant
Joel Cooper’s team, Canada
600 BCE – 1500
Ancient healers in India, China, Greece and the Islamic world link breath to life and describe the lungs, though no one yet knows what air does.
200 BCE
c. 300 BCE – 300 CE (dates debated)
The great Ayurveda texts of ancient India were written and edited over several centuries, so their dates are uncertain. They describe prana, the vital air, moving through channels called pranavaha srotas, with roots in the heart. They also name breathing troubles such as shvasa (breathlessness) and kasa (cough).
Why it mattered. Long before anyone knew about oxygen, people saw that breath and life go together.
100 BCE
c. 1st century BCE (dates debated)
The Yellow Emperor’s Inner Classic is a founding text of Chinese medicine. Historians date its parts to between the Warring States period and the Han dynasty. In this tradition the lung governs qi: it breathes in clear qi from nature and breathes out stale qi from the body.
Why it mattered. It pictured the lungs as an exchange between the body and the outside air, which is close to the truth.
170
c. 160–200 CE
The Greek doctor Galen taught that we breathe to cool the heat of the heart and to draw in pneuma, a kind of life spirit carried by the air. Earlier, around 250 BCE, Erasistratus in Alexandria had said that pneuma travels from the lungs into the heart and arteries.
Why it mattered. Galen’s ideas ruled medicine in Europe and the Islamic world for well over a thousand years.
1242
c. 1242
In his Commentary on Anatomy in Avicenna’s Canon, the Damascus-born doctor Ibn al-Nafis said Galen was wrong: blood cannot pass through tiny holes in the wall of the heart. Instead it travels from the right side of the heart to the lungs, mixes with air, and returns to the left side. Europe did not know his work; a copy was found in a Berlin library in 1924.
Why it mattered. It is widely credited as the first correct description of the pulmonary circulation, about 300 years before Europeans described it.
1600 – 1800
Air pumps, bellows and new gases show that one part of the air keeps us alive, and that breathing is a slow, gentle fire.
1660
1660–1662
Boyle and his assistant Hooke built an air pump and sucked the air out of glass jars holding mice, birds and insects. The animals collapsed, and a candle went out. In 1662 Boyle published the rule now called Boyle’s law: squeeze a gas into half the space and its pressure doubles.
Why it mattered. Boyle’s law is exactly how you breathe: your chest grows, the pressure inside drops, and air rushes in.
1667
People argued about whether the moving of the lungs or the air itself kept us alive. In front of the Royal Society, Hooke pumped air into an opened dog’s lungs with bellows. Even when he kept the lungs still and just let fresh air flow through, the dog lived, and it failed when the fresh air stopped.
Why it mattered. It showed that fresh air, not movement, is what the body needs, and it was an early step toward artificial ventilation.
1772
c. 1771–1772 (published 1777)
The pharmacist Scheele heated chemicals and collected a gas that made things burn brightly. He called it ‘fire air’. His book about it was not printed until 1777, so others published first.
Why it mattered. He was probably the first to make oxygen, which is why historians share the credit.
1774
1 August 1774
Priestley used a big lens to focus sunlight on red mercury oxide and collected the gas it gave off. A candle burned brilliantly in it, and a mouse lived longer in it than in ordinary air. Later he breathed some himself and said it felt light and easy.
Why it mattered. Oxygen is the gas your lungs exist to collect.
1777
Lavoisier, who went on to name oxygen, showed that animals use up this part of the air and breathe out carbon dioxide, just as a burning candle does. Only the oxygen mattered; the rest of the air came in and went out unchanged.
Why it mattered. It explained what breathing is really for: burning food with oxygen to release energy.
1783
1782–1790
In the winter of 1782–83 Lavoisier and Laplace put a guinea pig inside a jacket of ice and measured how much ice its body heat melted. Around 1789–90 Lavoisier and Séguin measured how much oxygen a person used when resting, eating and working. Marie-Anne Lavoisier took part and drew the experiments.
Why it mattered. These were the first measurements of how fast a body burns oxygen.
1800 – 1925
Doctors listen to the chest, measure breaths, find the TB germ and see inside with X-rays, while physiologists learn how oxygen moves.
1816
Laennec did not want to press his ear to a young woman’s chest, so he rolled paper into a tube and listened through it. He heard the heart more clearly than ever, and soon made wooden tubes. In 1819 he published a book linking the sounds of the chest to lung diseases.
Why it mattered. Doctors could now listen to the lungs, which they still do every day.
1846
Hutchinson built a spirometer, a bell floating in water that rises as you blow into it. He measured thousands of people and named the biggest breath you can blow out the ‘vital capacity’. He found it grows with height and falls with age and illness.
Why it mattered. Blowing into a spirometer is still how doctors test lungs today.
1882
24 March 1882
Tuberculosis was one of the biggest killers in the world. At a meeting of the Berlin Physiological Society, Koch showed the microbe that causes it, using more than 200 slides he had prepared. The date, 24 March, is now World TB Day.
Why it mattered. Knowing the cause made it possible to find TB, stop it spreading and, later, cure it, a fight that still matters most in India.
1895
8 November 1895
Röntgen discovered a new kind of invisible ray that passes through soft flesh but not bone, and made a picture of the bones in his wife’s hand. Within months doctors were using X-rays.
Why it mattered. The chest X-ray became a key way to see lung disease such as TB and pneumonia.
1904
The team measured how much oxygen blood holds at different pressures. The curve was S-shaped, and more carbon dioxide made blood hold oxygen less tightly. This is the Bohr effect, and it relied on a precise instrument that Krogh designed.
Why it mattered. Busy muscles make carbon dioxide, so they get more oxygen exactly when they need it.
1910
1909–1910
Christian Bohr thought lung cells actively pumped oxygen into the blood. August and Marie Krogh, testing on themselves with a single-breath method, showed that oxygen and carbon dioxide just drift across the thin wall from high pressure to low. Marie’s single-breath idea is still behind a lung test used today.
Why it mattered. It showed why the lungs need a huge, thin surface: diffusion alone has to do the job.
1925 – 1990
Iron lungs, ventilators, surfactant, transplants and oximeters keep failing lungs going, while smoking and toxic gas show how lungs can be harmed.
1928
12 October 1928
Polio could paralyse the muscles used for breathing. Drinker and Shaw built a sealed metal tank that lowered and raised the air pressure around a patient’s body, so air flowed in and out of the lungs. Its first patient was an eight-year-old girl at Boston Children’s Hospital.
Why it mattered. Iron lungs kept thousands of polio patients alive, and they copy the same pressure trick your own chest uses.
1929
Von Neergaard found that lungs filled with liquid inflate far more easily than lungs filled with air. He reasoned that surface tension in the wet lining of the air sacs pulls them shut, and guessed something must lower it.
Why it mattered. His idea was ignored for about 25 years, but it was the first clue to surfactant.
1950
1950 and 1964
In 1950, two large studies, one in the USA and one in Britain, compared people with lung cancer to people without it. Nearly all the patients were smokers. In 1964 the US Surgeon General’s report said plainly that cigarette smoking causes lung cancer.
Why it mattered. It is the main reason doctors and governments now fight tobacco.
1952
26 August 1952
A polio epidemic left hundreds of people in Copenhagen unable to breathe, and there were very few iron lungs. The anaesthetist Ibsen put a tube into the windpipe of 12-year-old Vivi Ebert and pushed air in with a squeezed rubber bag. Hundreds of medical students then took turns squeezing bags day and night, and far fewer patients died.
Why it mattered. Pushing air in, instead of pulling it in, is how modern ventilators work, and Ibsen went on to open what is often called the first intensive care unit.
1956
1955–1957
While studying how nerve gases harm the lungs, Pattle in Britain noticed that foam from lungs was unusually long-lasting. Clements in the USA measured lung fluid on a special balance and showed it could make surface tension very low. The substance was named surfactant.
Why it mattered. Surfactant stops the tiny air sacs from collapsing each time you breathe out.
1957
1955–1958
Forrest Bird, a pilot and inventor who had worked on oxygen masks for high-flying airmen, designed a small ventilator that pushed air into the lungs through a mask or tube. The Bird Mark 7 became one of the first mass-produced, reliable ventilators.
Why it mattered. Small ventilators could be used on any hospital ward, not just in a room of iron lungs.
1959
Many babies born too early died of hyaline membrane disease, and nobody knew why. Avery and Mead tested fluid from the lungs of babies who had died and found it was missing surfactant. Without it, the babies’ air sacs collapsed with every breath.
Why it mattered. Their discovery led to surfactant treatment, which has saved hundreds of thousands of newborn babies.
1974
1972–1975
In 1972 the engineer Aoyagi was annoyed by a ‘noise’ in his light signals that went up and down with each heartbeat. He realised that the pulsing red and infrared light could reveal how much oxygen the blood carried. He presented the idea in 1974, and in 1975 Nihon Kohden sold the first ear oximeter.
Why it mattered. Every clip-on finger oximeter, used by millions in the COVID-19 pandemic, works on his idea.
1980
12 January 1980
Fujiwara’s team in Japan made a surfactant from cow lungs and gave it through a tube to ten very sick premature babies. Their oxygen levels improved quickly, and their X-rays cleared. The results were published in The Lancet.
Why it mattered. It turned Avery’s discovery into a treatment now used in newborn units around the world.
1983
1963 and 1983
In 1963 James Hardy performed the first human lung transplant, but the patient lived only 18 days. Twenty years later Joel Cooper’s team in Toronto gave a single new lung to Tom Hall, who lived for years. Better drugs to calm the immune system made the difference.
Why it mattered. Transplants now give people with failing lungs a second chance.
1984
2–3 December 1984
About 45 tonnes of methyl isocyanate gas leaked from a pesticide factory at night and spread over the sleeping city. Thousands died within days, and estimates of the total deaths vary widely. Hundreds of thousands of survivors were left with damaged lungs and eyes.
Why it mattered. It is one of the worst industrial disasters ever, and a reminder that what we breathe can kill.
1990 – today
Tobacco treaties, clean-air limits and a pandemic put lung health at the centre of public health, especially in India.
2005
2003–2005
The World Health Assembly adopted the Framework Convention on Tobacco Control on 21 May 2003, and it came into force on 27 February 2005. India ratified it in 2004, and in 2003 passed its own tobacco law, COTPA.
Why it mattered. Taxes, warnings and smoke-free places have helped cut tobacco use, including in India.
2021
April–May 2021
In the COVID-19 second wave, sick lungs could not take in enough oxygen, and hospitals ran short. The government told Parliament that daily demand for medical oxygen peaked at nearly 9,000 tonnes, about three times the first wave’s peak. Special Oxygen Express trains and air force planes rushed oxygen tankers across the country.
Why it mattered. It showed a whole country how vital the oxygen in every breath is.
2021
22 September 2021
WHO halved its guideline for fine PM2.5 dust to a yearly average of 5 micrograms per cubic metre, with a 24-hour limit of 15. These tiny particles slip deep into the air sacs. Most cities in India are many times above the new limit.
Why it mattered. Clean air is one of the biggest things that keeps lungs healthy for life.
By the numbers
Share of Indian adults (15 and over) using any form of tobacco, smoked or smokeless, in the two rounds of the Global Adult Tobacco Survey.
By the numbers
WHO estimates of tuberculosis incidence in India from the Global TB Report 2025: a 21% fall, but India still has about a quarter of the world’s cases.
Did you know?
Your lungs hold about 480 million tiny air sacs, according to careful counts of adult lungs.
The stethoscope began as a rolled-up sheet of paper, because Laennec felt awkward putting his ear on a patient’s chest.
In Copenhagen in 1952, hundreds of medical students squeezed rubber bags by hand, day and night, to breathe for polio patients.
Ibn al-Nafis described blood passing through the lungs about 300 years before European anatomists, but his book was only rediscovered in Berlin in 1924.
The pulse oximeter was born from a nuisance: a heartbeat ‘noise’ in a light signal that Takuo Aoyagi was trying to cancel out.
The people
129 – c. 216 · Physician · Pergamon (today Türkiye)
Taught that breathing cools the heart and brings in pneuma; his ideas lasted over a thousand years.
c. 1213 – 1288 · Physician · Damascus (Syria), worked in Cairo
First to describe blood passing through the lungs to pick up air.
1635 – 1703 · Natural philosopher · England
Built Boyle’s air pump and kept a dog alive with bellows.
1742 – 1786 · Pharmacist and chemist · Sweden (born in Swedish Pomerania)
Probably made oxygen first, but published late.
1733 – 1804 · Minister and chemist · England
Made oxygen with sunlight and a lens in 1774 and tested it on a mouse and himself.
1743 – 1794 · Chemist · France
Named oxygen and showed that breathing is a slow burning.
1758 – 1836 · Scientist, translator and illustrator · France
Worked in the lab and drew the famous breathing experiments.
1781 – 1826 · Physician · France
Invented the stethoscope and linked chest sounds to lung disease.
1811 – 1861 · Surgeon · England
Invented the spirometer and named vital capacity.
1843 – 1910 · Physician and microbiologist · Germany
Found the germ that causes tuberculosis.
1874 – 1943 · Physician and physiologist · Denmark
Helped prove that oxygen diffuses into the blood, and devised a single-breath lung test.
1911 – 2007 · Anaesthetist · Denmark
Saved polio patients by pushing air into their lungs, and founded intensive care.
1927 – 2011 · Paediatrician · USA
Showed that premature babies lack surfactant, opening the way to a cure.
1936 – 2020 · Engineer · Japan
Invented pulse oximetry, measuring blood oxygen with light.
Where it happened
Sources
Dates marked “c.” are approximate, and historians sometimes disagree about who was first. If you spot a mistake, tell us.
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