From pre-science alchemists to modern researchers, humans have always sought the chemistry of life. But the same can be said for the chemistry of death.
Four thousand years before mustard gas choked the trenches of World War I, Vedic kingdoms unleashed smoke screens and sleep-inducing toxins on the battlefields of India [source: Coleman]. Throughout antiquity, the Greeks, Romans and Spartans wielded chemical agents that burned the lungs, blinded the eyes, disrupted the bowels and scorched the skin.
Like murderous djinn unleashed from a lamp, these silent and often-invisible killers drifted across the battlefield in a wave of indiscriminate suffering and death.
But it wasn't till the 20th century that chemical warfare reached its full, terrifying potential. Prepare to explore 10 of the scariest chemical weapons ever developed.