Louis Pasteur

LOUIS PASTEUR
Louis Pasteur; December 27, 1822 – September 28, 1895) was a French chemist and microbiologist born in Dole. He is remembered for his remarkable breakthroughs in the causes and preventions of diseases. His discoveries reduced mortality from puerperal fever, and he created the first vaccine for rabies and anthrax. His experiments supported the germ. He was best known to the generalpublic for inventing a method to stop milk and wine from causing sickness, a process that came to be called pasteurization. He is regarded as one of the three main founders of microbiology, together with Ferdinand and Robert Koch. Pasteur also made many discoveries in the field of chemistry, most notably the molecular basis for the asymmetry of certain crystals. His body lies beneath the InstitutePasteur in Paris in a spectacular vault covered in depictions of his accomplishments in Byzantine mosaics.

Early life and biography
Louis Pasteur was born on December 27, 1822, in Dole in the Jura region of France, into the family of a poor tanner. Louis grew up in the town of Arbors. He gained degrees in Letters and in Mathematical Sciences before entering the École Normale Supérieure, anelite college. After serving briefly as professor of physics at Dijon Lycée in 1848, he became professor of chemistry at the University of Strasbourg, where he met and courted Marie Laurent, daughter of the university's rector, in 1849. They were married on May 29, 1849, and together had five children, only two of whom survived to adulthood; the other three died of typhoid. These personal tragediesinspired Pasteur to try to find cures for diseases such as typhoid.

Work on chirality and the polarization of light
In Pasteur's early work as a chemist, he resolved a problem concerning the nature of tartaric acid (1848). A solution of this compound derived from living things (specifically, wine) rotated the plane of polarization of light passing through it. The mystery was that tartaricacid derived by chemical synthesis had no such effect, even though its chemical reactions were identical and its elemental composition was the same. This was the first time anyone had demonstrated chiralmolecules.
Pasteur's doctoral thesis on crystallography attracted the attention of W. T. Fuillet and he helped Pasteur garner a position of professor of chemistry at the Faculté (College)of Strasbourg.
In the year of 1854, Louis was named Dean of the new Faculty of Sciences in Lille. (It was on this occasion that Pasteur uttered his oft-quoted remark: "...dans les champs de l'observation, le hasard ne favorise que les esprits préparés" (In the field of observation, chance favors only the prepared mind). In 1856, he was made administrator and director of scientific studies of the ÉcoleNormale Supérieure.

Germ theory of disease
Pasteur demonstrated that fermentation is caused by the growth of micro-organisms, and that the emergent growth of bacteria in nutrient broths is not due to spontaneous generation but rather to biogenesis.
He exposed boiled broths to air in vessels that contained a filter to prevent all particles from passing through to the growth medium, and even invessels with no filter at all, with air being admitted via a long tortuous tube that would not allow dust particles to pass. Nothing grew in the broths unless the flasks were broken open; therefore, the living organisms that grew in such broths came from outside, as spores on dust, rather than spontaneously generated within the broth. This was one of the last and most important experiments disprovingthe theory of spontaneous generation. The experiment also supported germ theory.
While Pasteur was not the first to propose germ theory(Girolamo Fracastoro, Agostino Bassi, Friedrich Henle and others had suggested it earlier), he developed it and conducted experiments that clearly indicated its correctness and managed to convince most of Europe it was true. Today he is often regarded as the...