Breakthrough!: How the 10 Greatest Discoveries in Medicine Saved Millions and Changed Our View of the World

2. How Cholera Saved Civilization: The Discovery of Sanitation

The largest delta in the world is a vast labyrinth of swampy waterways, tall grasses, mangrove forests, and brackish water. Formed from the Ganges and Brahmaputra rivers, it drains through 40,000 square miles along southern Bangladesh and a small corner of India before emptying into the Bay of Bengal. But the Ganges Delta is not merely large: It is also one of the most fertile regions in the world, churning with an enormous variety of life, from microscopic plankton to walking cat fish, from parrots, pythons, and crocodiles to the endangered Bengal tiger. In 1816, two somewhat less ...