Salvarsan 606 - the first magic bullet
In 1900, Ehrlich put forward the concept of a magic bullet when he argued that a chemical could deliberately target bacteria in the human body and kill those bacteria.
Ehrlich tested arsenic compounds to find a cure for syphilis.
In 1909, a Japanese scientist called Sahachiro Hata retested all of the compounds and discovered the first magic bullet, Salvarsan 606.
This was the 606th compound of Salvarsan (a drug containing arsenic), so it gave the drug its name.
Salvarsan 606 was able to kill the bacteria that cause syphilis.