The Germ Theory of Disease: Pasteurization

In the mid-1800s a French chemist named Louis Pasteur discovered, while examining the fermentation of alcohol, that the process is caused by microscopic organisms he named bacteria. Upon further examination he discovered that high heat killed the bacteria.  This was very important because it led to the discovery that bacteria can cause disease.  This discovery led him to develop the method of pasteurization, that we use most commonly today to kill germs in milk.