Louis Pasteur

Louis Pasteur was an example of a truly gifted person who made many wildly diverse discoveries in many different areas of science. He was a world-renowned French chemist and biologist whose work paved the way for branches of science and medicine such as stereochemistry, microbiology, virology, immunology, and molecular biology. He also proved the germ theory of disease, invented the process of pasteurization, fermentation, and developed vaccines for many diseases, including rabies.
Pasteur was born on December 27, 1822 in Dole, France, and grew up in the small town of Arbois. As a young boy, Pasteur showed no particular interest in science. His talents were mainly drawing and painting. At age thirteen, he could draw remarkable pictures of his sisters, mother, and the river that ran by his home. During his youth, he developed an ambition to become a teacher. While still in his teens, he went to Paris to study in a famous school called Lyce St. Louis. During his studies to become a teacher, he was fascinated by a chemistry professor, Monsieur Jean-Baptist Dumas. He wrote home excitedly about these lectures, and decided that he wanted to learn to teach chemistry and physics, just like his favorite professor.
In 1847 he earned a doctorate at the Ecole Normale in Paris, with a focus on both physics and chemistry. Becoming an assistant to one of his teachers, he began research that led to a significant discovery. He found that a beam of polarized light was rotated to either the right or the left as it passed through a pure solution of naturally produced organic nutrients, whereas when polarized light was passed through a solution of artificially synthesized organic nutrients, no rotation took place. If bacteria or other microorganisms were placed in the latter solution, then after a while it would also rotate light to the right or left. From this, he concluded that organic molecules exist in one of two forms, "left-handed" or "right-handed" forms.
After spending several years researching and teaching at Dijon and Strasbourg, Pasteur moved in 1854 to the University of Lille, where he became the professor of chemistry and dean of the faculty of sciences. There, a main focus of research was on the manufacture of alcoholic beverages. Pasteur immediately began researching the process of fermentation. He was able to demonstrate that the desired production of alcohol in fermentation is because of yeast, and that the undesired production of substances that make wine sour is because of the presence of additional organisms like bacteria. The souring of wine and beer had caused a major economic problem in France. Pasteur helped to solve the problem by proving that heating the starting sugar solutions to a high temperature would eliminate the bacteria.
Pasteur then extended his studies of this subject to other problems like the souring of milk, and proposed a similar solution, which consisted of heating the milk to high temperatures and pressure before bottling. This process kills disease-causing bacteria and viruses and became known as pasteurization.
After his studies on fermentation and pasteurization, Louis was convinced the microbes were useful for many tasks in the world, but also at the heart of a thousand dangerous things, too. Many scientists at the time believed humans, animals, and insects were not produced by parents of their own kind, but that they were spontaneously generated. Fermentation and rotting never took place unless the microbes were present, but it was generally believed that the microbes were caused by the rotting, instead of the microbes themselves causing the rotting. To prove this to the scientific community, Pasteur had to do many experiments to prove that things do not spontaneously generate. To prove this, he, with the help of Professor Antonie-Jrme Balard, invented a flask with a long downward S-shape. He then did many experiments, and all proved him correct! The scientists were proven wrong, and it is now accepted as the truth that things cannot spontaneously generate. Even today, the same swan-necked flasks Pasteur used can be seen, still free of germs.
In 1865, Pasteur was summoned from Paris to come to the aid of the silk industry in southern France. The country?s enormous production of silk had suddenly halted because of a disease of silkworms, reaching epidemic proportions. Suspecting that certain microscopic objects found in the diseased silkworms, moths, and eggs were disease-producing organisms, Pasteur experimented with controlled breeding and