The Theory of the Four Humours

Medieval medicine was built on the ancient Theory of the Four Humours, from the Greek doctors Hippocrates and Galen. The body was thought to contain four humours (fluids) that had to stay in balance:

Treatment by opposites: a "hot" fever might be treated with "cold" foods; too much blood was drained by bloodletting or leeches to rebalance the body.

God, miasma and the Black Death

People in the Middle Ages had many ideas about what caused disease. Most were wrong, and few could be tested:

• Supernatural / religious: illness was a punishment from God for sin, or the work of the Devil; astrology (the movement of the planets) was blamed too.
• Miasma theory: disease was carried in "bad air" or bad smells.
• The Church controlled medicine, ran hospitals, and preserved Galen's ideas — but also discouraged people from challenging them.

The Black Death (1348–49): a huge plague blamed on God, miasma and the planets. Treatments — praying, herbs, bleeding, even ringing bells — were useless, because no one understood the real cause.

Which theory?

Vesalius and Harvey challenge Galen

The Renaissance ("rebirth") brought new curiosity, dissection and the printing press to spread ideas. Two men corrected Galen, who had been trusted for over 1,000 years:

• Andreas Vesalius — his book De Humani Corporis Fabrica (1543) corrected Galen's anatomy using real human dissection, proving Galen had made mistakes.
• William Harvey (1628) — proved that blood circulates around the body, pumped by the heart, disproving Galen's idea that the liver made blood that was "burned up".

Thomas Sydenham, the "English Hippocrates", stressed carefully observing disease at the bedside.

Continuity, though: these were breakthroughs in understanding, not treatment. Everyday care changed little at first, and the Great Plague of 1665 was still met with useless remedies.

Who disproved Galen?

Jenner and the smallpox vaccine

Smallpox was a deadly, disfiguring disease. In 1796, Edward Jenner noticed that milkmaids who had caught the mild disease cowpox never got smallpox.

• He tested his idea by infecting a boy with cowpox, then exposing him to smallpox — the boy did not catch it.
• He called the method vaccination (from vacca, Latin for cow).

Why it mattered: vaccination was the first safe way to prevent a disease. But Jenner could not explain why it worked — that had to wait for germ theory decades later.

Pasteur and Koch prove germs cause disease

For centuries people blamed miasma ("bad air"). The truth came from the laboratory:

• Louis Pasteur (1861) — published his Germ Theory of Disease: tiny microbes (germs), not bad air, cause disease and decay.
• Robert Koch — identified the specific microbes behind particular diseases (such as anthrax and TB), and developed ways to stain and photograph them.

Turning point: germ theory finally explained the real cause of disease, replacing miasma and the four humours for good.

Who proved germs cause disease?

Anaesthetics and antiseptics

Before the 1840s surgery was agonising and often fatal — patients died of pain, blood loss and infection. Two breakthroughs made surgery far safer:

• Anaesthetics: James Simpson discovered that chloroform (1847) put patients safely to sleep, ending the pain of surgery.
• Antiseptics: using germ theory, Joseph Lister used carbolic acid (1867) to kill germs during operations, sharply cutting deaths from infection.

Other reformers: Florence Nightingale (Crimea; Notes on Nursing, 1859) made hospitals cleaner and nursing a trained profession; John Snow traced cholera to a water pump (Broad Street, 1854), and the Public Health Act 1875 improved sewers and clean water.

Misconception alert: anaesthetics at first led to more deaths — surgeons operated more boldly before antiseptics existed (the "Black Period" of surgery). It took antiseptics too to make surgery truly safer.

Who introduced antiseptics?

Penicillin and the NHS

The 20th century transformed medicine again:

• Alexander Fleming discovered penicillin in 1928 — the first antibiotic, from a mould that killed bacteria. He could not mass-produce it.
• Florey and Chain found how to mass-produce penicillin in the 1940s, in time to save wounded soldiers in the Second World War.
• The NHS (1948) gave everyone free healthcare, paid for by taxes — a huge change in access to medicine.
• Watson & Crick (1953) discovered the structure of DNA; later the Human Genome Project mapped human genes.

Modern medicine now relies on antibiotics, vaccines, advanced surgery, and lifestyle campaigns (e.g. against smoking) — plus the science of genetics.

Name the drug

When did the NHS begin?

Person ↔ contribution

Tap a person or thing on the left, then tap its contribution on the right.

The trenches: conditions and wounds

The historic environment is the British sector of the Western Front, 1914–18. The trenches created terrible medical problems:

• Wounds: shrapnel (from exploding shells) caused most injuries; rifle and machine-gun fire caused deep wounds and broken bones.
• Infection: the fertile Belgian mud carried bacteria into wounds, causing gas gangrene and other deadly infections.
• Gas attacks: chlorine (first used 1915), then phosgene and mustard gas — choking, blinding and burning soldiers.
• Trench conditions: trench foot (from cold, wet feet) and shell shock (psychological trauma) were widespread.

Key point: injuries were made far worse by the infected soil, so doctors urgently needed better ways to stop wounds becoming fatal.

New techniques on the Western Front

The scale of casualties drove rapid medical progress:

• The Thomas splint — held a broken leg firmly still, dramatically cutting deaths from leg fractures (survival from around 20% up to about 80%).
• Blood transfusions — using sodium citrate to stop blood clotting and refrigeration, blood could be stored; a Blood Depot at Cambrai (1917) stockpiled blood before battle.
• Mobile X-ray units — located bullets and shrapnel deep in the body.
• Brain surgery — pioneered by Harvey Cushing; plastic surgery for facial wounds by Harold Gillies.

The RAMC (Royal Army Medical Corps) and FANY (First Aid Nursing Yeomanry) organised the care of the wounded.

The chain of evacuation

Wounded soldiers were moved back from the front line through a chain of evacuation, each stage giving more advanced care:

Casualty Clearing Stations did the major surgery — and used the new techniques like the Thomas splint and blood transfusions.

The Thomas splint

Where was the major surgery?

The first poison gas

Timeline: c1250 → present

Put the developments in order

Tap the developments in the correct time order, from earliest to latest.

What drove change (and continuity)?

The exam rewards linking developments to the big factors that caused them — and explaining why change was sometimes slow:

• Science & technology: the microscope, printing press and germ theory made real progress possible.
• Individuals: Vesalius, Harvey, Pasteur, Lister, Fleming — but they usually built on others' work.
• War: the Western Front sped up surgery, transfusions and X-rays.
• Government: the Public Health Act 1875 and the NHS 1948 improved everyone's health.
• Attitudes & the Church: in the Middle Ages the Church preserved Galen but discouraged new ideas — a brake on change.

Big idea: for centuries ideas changed but treatment did not. Only once germ theory was proven did understanding, prevention and cure finally advance together.

Why so little changed for so long

Using sources on the Western Front

The historic environment paper asks you to work with sources and to suggest useful enquiries. Two habits win marks:

• Judge usefulness by provenance — who made the source, when and why. A soldier's letter and an official RAMC report tell you different things.
• Follow up a source — suggest a detail to investigate and a type of source that would help (e.g. hospital records, photographs, war diaries).

Tip: link sources to your own knowledge of the trenches, wounds and the chain of evacuation — that is exactly what the mark scheme rewards.

Thinking like a historian

The essentials to remember

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