In 1922, Louis Pasteur was born in France. He excelled at chemistry and gained a teaching position at the University of Strasbourg.  The scientific community still thought that diseases were caused by putrid air, but the micro biotic theory of invisible germs as a cause of disease was developing.  Pasteur demonstrated that fermentation was caused by microorganisms, and he found a way to destroy micro-organisms without destroying the food by heating it to very high temperatures for a very short time.  Pasteurization was born. 

Pioneering German scientist Robert Koch and Louis Pasteur became the fathers of bacteriology.  When smallpox was decimating populations, Dr. Edward Jenner discovered that English milkmaids who contracted cowpox were then immune to smallpox. He confirmed his theories by experimenting on his patients, and amazingly none of them died! Pasteur then immunized chickens using weakened cholera bacterial cultures, and he also experimented with rabies vaccines.  Pasteur’s greatest accomplishment was convincing medical practitioners to sterilize their hands and their instruments before moving from one patient to another, saving many human lives.