Ignaz Semmelweis struggled for years to promote his... ground-breaking handwashing policies but was beaten to death in 1865. He was just 47.
Jabir ibn Hayyan recognised that experiments were important to science and transformed the spiritual practice of alchemy into what would now be known as modern chemistry.
For the next 2000 years, the world depended on the theories of Democritus and Aristotle, until John Dalton came up with the Modern Atomic Theory in 1808.
Did the lack of knowledge of Chemistry lead to the downfall of one of the greatest armies in history?