Pasteur's father was one of Napoleon's conscripts and had won the Cross of the legion of Honour in the field of battle.
The French chemist and biologist Louis Pasteur is famous for his germ theory and for the development of vaccines. He made major contributions to chemistry, medicine, and industry. His discovery that diseases are spread by microbes, which are living organisms—bacteria and viruses—that are invisible to the eye, saved countless lives all over the world.
The tanner's son
Louis Pasteur was born on December 27, 1822, in the small town of Dôle, France. His father was a tanner, a person who prepares animal skins to be made into leather. The men in Pasteur's family had been tanners back to 1763, when his great-grandfather set up his own tanning business. Part of the tanning process relies on microbes (tiny living organisms). In tanning, microbes prepare the leather, allowing it to become soft and strong. Other common products such as beer, wine, bread, and cheese depend on microbes as well. Yet, at the time Pasteur was a child, few people knew that microbes existed.
Pasteur's parents, Jean-Joseph Pasteur and Jeanne Roqui, taught their children the values of family loyalty, respect for hard work, and financial security. Jean-Joseph, who had received little education himself, wanted his son to become a teacher at the local lycée (high school). Pasteur attended the École Primaire (primary school), and in 1831 entered the Collège d'Arboix. He was regarded as an average student, who showed some talent as an artist. Nonetheless, the headmaster encouraged Pasteur to prepare for the École Normale Supérieure, a very large training college for teachers located in Paris. With this encouragement he applied himself to his studies. He swept the school prizes during the 1837 and 1838 school year.
Pasteur went to Paris in 1838 at the age of sixteen. His goal was to study and prepare for entering the École Normale. Yet, he returned to Arboix less than a month later, overwhelmed with homesickness. In August of 1840 he received his bachelor's degree in letters from the Collège Royal de Besançon and was appointed to tutor at the Collège. In 1842, at age twenty, he received his bachelor's degree in science. He then returned to Paris, and was admitted to the École Normale in the autumn of 1843. His doctoral thesis (a long essay resulting from original work in college) was on crystallography, the study of forms and structures of crystals.
Investigations into crystals
In 1848, while professor of physics at the lycée of Tournon, the minister of education granted Pasteur special permission for a leave of absence. During this time, Pasteur studied how certain crystals affect light. He became famous for this work. The French government made him a member of the Legion of Honor and Britain's Royal Society presented him with the Copley Medal.
Studies on fermentation
In 1852 Pasteur became chairman of the chemistry department at the University of Strasbourg, in Strasbourg, France. Here he began studying fermentation, a type of chemical process in which sugars are turned into alcohol. His work resulted in tremendous improvements in the brewing of beer and the making of wine. He also married at this time.
In 1854, at the age of thirty-one, Pasteur became professor of chemistry and dean of sciences at the new University of Lille. Soon after his arrival at Lille, a producer of vinegar from beet juice requested Pasteur's help. The vinegar producer could not understand why his vinegar sometimes spoiled and wanted to know how to prevent it.