Russian chemist who published the influential History of Chemistry book in 1949. He also invented a synthetic chemical reaction called Walden Inversion.
Walden was greatly influenced by his work with Nobel Prize winning chemist Wilhelm Ostwald.
Because of the political tensions in his native Latvia, he decided to leave the country to settle in Germany.
He lost both of his parents when he was five years old but was able to complete his education with the financial support of his two older brothers.
In 1924, he was invited back to teach in his native Latvia, but he did not care for Lenin's reforms and declined the offer.