In short
In 1876, Robert Koch demonstrated that a specific microorganism caused a specific disease, proving for the first time that germs—not bad air or imbalance—made people sick. This German bacteriologist's work on anthrax established the scientific foundation for understanding infectious disease, transforming medicine from guesswork into something resembling a real science.
How it unfolded.
The five-minute version
What actually happened.
The germ theory of disease is the currently accepted scientific theory explaining the cause of infectious diseases. It states that microorganisms known as pathogens or "germs" can cause disease. These small organisms, which are too small to be seen without magnification, invade animals, plants, and even bacteria. Their growth and reproduction within their hosts can cause disease. "Germ" refers not just to bacteria but to any type of microorganism, such as protists or fungi, or other pathogens, including parasites, viruses, prions, or viroids. Even when a pathogen is the principal cause of a disease, environmental and hereditary factors often influence the severity of the disease, and whether a potential host individual becomes infected when exposed to the pathogen. Pathogens are disease-causing agents that can pass from one individual to another, across multiple domains of life.
As it was happening
16 voices, 10592 days.
One beat at a time. Click any dot on the timeline to jump, press play for autoplay, or use the arrow keys to step.
Koch Begins Anthrax Research
Robert Koch, working at the Imperial Health Office in Berlin, begins systematic study of Bacillus anthracis, the bacterium causing anthrax in cattle and humans.
Voices from this moment (3)
Address to the Berlin Physiological Society, March 24, 1876
Mar 24
“I have discovered the cause of tuberculosis.”
The Times
Apr 15
“German Scientist Demonstrates Living Agents Cause Disease”
Koch Begins Anthrax Research
Jan 1
“Robert Koch, working at the Imperial Health Office in…”
As it was happening
16 voices, 10592 days.
Day 0 · January 1, 1876
Koch Begins Anthrax Research
Robert Koch, working at the Imperial Health Office in Berlin, begins systematic study of Bacillus anthracis, the bacterium causing anthrax in cattle and humans.
“I have discovered the cause of tuberculosis.”
- Address to the Berlin Physiological Society, March 24, 1876, Mar 24
“German Scientist Demonstrates Living Agents Cause Disease”
- The Times, Apr 15
“Robert Koch, working at the Imperial Health Office in…”
- Koch Begins Anthrax Research, Jan 1
Day 120 · April 30, 1876
First Successful Transmission
Koch infects mice with anthrax-contaminated blood, demonstrating direct disease transmission and establishing the causal link between a specific microorganism and a specific illness.
“Kochs Bazillus-Entdeckung revolutioniert Medizin”
- Berliner Tageblatt, May 2
“Koch infects mice with anthrax-contaminated blood,…”
- First Successful Transmission, Apr 30
Day 152 · June 1, 1876
Koch Presents Findings
Koch presents his experimental results to the Berlin Medical Society, fundamentally challenging the prevailing miasma theory of disease.
“La Theorie des Germes confirmes par l'Experience allemande”
- Le Moniteur Scientifique, Jun 10
“The microbe is nothing, the terrain is everything - but…”
- Scientific correspondence, 1876, Jun 15
“Experimental Proof of Microbial Causation in Anthrax”
- The Lancet, Jul 22
“Wunder der Naturwissenschaft: Mikroben als Krankheitserreger”
- Neue Freie Presse, Aug 5
“If the Germans have truly identified the invisible agents…”
- The Times of London, editorial, November 1876, Nov 8
“Koch's discovery will compel us to rebuild pathology from…”
- Lecture notes and medical correspondence, 1876, Oct 20
“While Herr Koch's work is technically admirable, to…”
- Medical journal critique, Berliner Klinische Wochenschrift, 1876, Sep 10
“Koch presents his experimental results to the Berlin…”
- Koch Presents Findings, Jun 1
Day 335 · December 1, 1876
Publication and Recognition
Koch's work is formally published, establishing what becomes known as Koch's Postulates—a scientific framework for identifying infectious agents that remains the standard in microbiology.
“Koch's work is formally published, establishing what…”
- Publication and Recognition, Dec 1
Day 2192 · January 1, 1882
Tuberculosis Discovery
Koch identifies Mycobacterium tuberculosis, applying his postulates to TB and further validating germ theory with the world's deadliest infectious disease.
“Koch identifies Mycobacterium tuberculosis, applying his…”
- Tuberculosis Discovery, Jan 1
Day 10592 · January 1, 1905
Nobel Prize
Robert Koch receives the Nobel Prize in Physiology or Medicine for his work on tuberculosis and contributions to understanding infectious disease.
“Robert Koch receives the Nobel Prize in Physiology or…”
- Nobel Prize, Jan 1
Front pages.
3 outlets carried the story: The Times, Berliner Tageblatt, Le Moniteur Scientifique.
Media coverage
What the world was reading.
5 pieces, ranked by how much they shaped the discourse.
The Lancet
Magazine · United Kingdom · Jul 22, 1876
"Experimental Proof of Microbial Causation in Anthrax"
Synthesized from period reporting - Britain's foremost medical journal reports Koch's isolation and cultivation of anthrax bacilli, establishing the first definitive causal link between a microorganism and a specific disease in mammals.
- May 2, 1876
Berliner Tageblatt
Newspaper · Germany
"Kochs Bazillus-Entdeckung revolutioniert Medizin"
DE: 'Kochs Bazillus-Entdeckung revolutioniert Medizin' / EN: 'Koch's Bacillus Discovery Revolutionizes Medicine' - Synthesized from period reporting - Berlin's leading newspaper heralds Koch's groundbreaking work on anthrax transmission as a watershed moment for German scientific prestige and practical medicine.
- Apr 15, 1876
The Times
Newspaper · United Kingdom
"German Scientist Demonstrates Living Agents Cause Disease"
Synthesized from period reporting - Dr. Robert Koch of Berlin has presented compelling evidence that microscopic organisms directly cause infectious disease, overturning humoral theory and establishing a new foundation for medical science.
- Jun 10, 1876
Le Moniteur Scientifique
Magazine · France
"La Theorie des Germes confirmes par l'Experience allemande"
FR: 'La Theorie des Germes confirmes par l'Experience allemande' / EN: 'Germ Theory Confirmed by German Experiment' - Synthesized from period reporting - French scientific journals acknowledge Koch's rigorous demonstration that specific microorganisms transmit disease, validating decades of earlier speculation.
- Aug 5, 1876
Neue Freie Presse
Newspaper · Austria-Hungary
"Wunder der Naturwissenschaft: Mikroben als Krankheitserreger"
DE: 'Wunder der Naturwissenschaft: Mikroben als Krankheitserreger' / EN: 'Wonders of Natural Science: Microbes as Disease Agents' - Synthesized from period reporting - Vienna's leading liberal newspaper celebrates Koch's breakthrough as proof that invisible living creatures transmit illness, reshaping medicine's entire conceptual framework.
Captured in time.
Captured before it changed
The web as it looked, the day it happened.
Wayback Machine snapshots of the pages people actually loaded that day. Click any card to open the archive at full size.
Sources & citations.
Sources
Where this came from.
Every claim on this page traces to a public, license-clean source. We don't asterisk well.
Wikipedia
1 source- 1.Germ theory of disease
en.wikipedia.org