Pasteur's Germ Theory

Louis Pasteur was a French chemist. In 1854 he was asked to invesgtigate why vats of beer were turning sour. According to the theory of spontaneous generation, these microorganisms were created by the mixture as it decayed. But Pasteur didn't believe this and suggested that microorganisms were affecting the beer and making it go sour. He was able to prove his theory when he discovered that microorganisms could be killed by heating the liquid.

Pasteur carried on and experimented with milk, vinegar and wine. He became conviced that liquids were contaminated with microorganisms floating in the air. Pasteur also found out that if he heated the mixture and then prevented bad air…