Knowledge about the body

Knowledge about the body increased greatly in the 19th century:

1. William Beaumont (America: 1822) studied the digestive system of Alexis St Martin, a Canadian who had an open hole into his stomach.
2. Theodor Schwann (Germany: 1839) realised that animal matter was made up of cells, not 'humours'. This was the vital breakthrough of knowledge that at last destroyed belief in the old 'humoral' pathology of the Greeks.
3. Henry Gray (Scotland: 1858) wrote 'Gray's Anatomy', which had over 1,000 illustrations. Many people bought a copy to own at home. After the 1870s, pupils started studying anatomy in schools.
4. Starling and Bayliss (England: 1902) discovered the first hormone.
5. Casimir Funk (Poland: 1912) discovered the first vitamins, and realised that some diseases were caused simply by poor diet.

Knowledge about disease

Louis Pasteur, French microbiologist and the 'father' of the germ theory of disease. Image first published in 1894.

Knowledge about disease also increased greatly in the 19th century.

Louis Pasteur (France: 1860s) discovered (by using a swan-necked flask) that germs cause disease. Before he made this discovery, doctors had noticed bacteria, but they believed it was the disease that caused the bacteria (the so-called theory of 'spontaneous generation') rather than the other way round.

One of the spin-offs of Pasteur's discovery was the pasteurisation [Pasteurisation: A process in which a liquid is heated to a specific temperature, in order to kill microorganisms in the liquid that could be damaging to health. ] of milk, which prevented it from going sour by killing the germs and sealing it from the air.

Other scientists also made crucial discoveries, among them:

1. Robert Koch (Germany: 1878), who discovered how to stain and grow bacteria in a Petri dish (named after his assistant Julius Petri). He was thus able to find which bacteria caused which diseases:
   • septicaemia (1878)
   • TB (1882)
   • cholera (1883).
2. In the same period other bacteria were discovered, including those that caused:
   • typhoid (1880s)
   • pneumonia (1880s)
   • plague (1894)
3. Patrick Manson (Britain: 1876) discovered that elephantiasis was caused by a nematode worm, and that mosquitoes were the vector (carrier). This was a breakthrough discovery, because researchers soon found out that other tropical diseases were transmitted by vectors such as mosquitoes (malaria and yellow fever) or tsetse flies (sleeping sickness).
4. Charles Chamberland (France: 1884) found that there are organisms even smaller than bacteria that also cause disease - he had discovered viruses.

Causes of improvements in physiology and pathology

1. The Industrial Revolution / inventions
   • There was a general atmosphere of scientific research and advance.
   • Louis Pasteur's first commission was to find a cure for sour wine, which set him off on his revolutionary course.
   • Joseph Jackson Lister (Britain: 1826) invented the multi-lens microscope, which allowed doctors to see very tiny things accurately.
   • Carl Ludwig (Germany: 1847) invented the kymograph, which allowed more accurate measurement of the pulse.
   • Wilhelm Roentgen (Germany: 1895) discovered x-rays.
   • Willem Einthoven (Holland: 1900) invented the electrocardiograph (measured heart activity).
2. Scientific knowledge
   • Jan Purkinje (Czechoslovakia: 1836) set up the first university department of physiology (science of how the body works).
   • Louis Pasteur started as a research chemist. He set up a team of researchers at the Pasteur Institute (1888).
   • Robert Koch developed his Postulates of how researchers should find a disease. These led to four basic procedures - make sure the germ in question is present in the sick specimen - grow a culture of that germ - inject it into a healthy specimen - see if the disease develops.
3. Social factors
   • Nationalism - eg the rivalry of Pasteur and Koch. Shibasaburo Kitasato (Japan) and Alexandre Yersin (France) raced to discover the plague bacterium in 1894.
   • The deaths of his two daughters motivated Louis Pasteur to redouble his efforts in the fight against disease.

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