Louis Pasteur

Louis Pasteur was born in 1822 in the small town of Dole in the Jura region of eastern France, the son of a tanner who had served as a sergeant in Napoleon's army.His father, determined that his son should rise beyond the family trade, drove him hard at his studies, and Louis, a patient and methodical child more gifted at drawing than at schoolwork, gradually found his footing in the sciences.

He entered the prestigious École normale supérieure in Paris and in 1848, at the age of twenty-six, made his first great discovery: examining tiny crystals of tartaric acid under a microscope, he showed that certain molecules existed in mirror-image forms, founding the field of stereochemistry and winning instant scientific fame.The first turning point came when wine and beer producers in northern France asked him to explain why their drinks sometimes spoiled.

Through painstaking experiments in the 1850s and 1860s he proved that fermentation was caused by living microorganisms, and in 1862 he perfected the gentle heating process, soon called pasteurization, that still protects the world's milk, wine, and beer.This work overturned the ancient theory of spontaneous generation and led directly to the germ theory of disease.

His second turning point came in 1879, when an accidentally weakened culture of chicken cholera bacteria failed to kill the birds it was injected into, and in fact protected them from later infection.Pasteur recognized that he had stumbled onto a general principle of vaccination, and within two years he had developed a vaccine against anthrax, then ravaging French livestock, and demonstrated it publicly in a dramatic field trial at Pouilly-le-Fort in 1881.

The climactic moment of his career came in July 1885, when a desperate mother brought to him a nine-year-old boy named Joseph Meister, savaged by a rabid dog.Pasteur, not even a physician, agonized over the decision before injecting his experimental rabies vaccine.

The boy lived, and the news swept the world.Donations poured in from every continent and in 1888 the Pasteur Institute opened its doors in Paris.Pasteur died there in 1895 at the age of seventy-two, and the institute he founded continues to lead microbial research to this day.

“Chance favors the prepared mind.”

“Science knows no country, because knowledge belongs to humanity.”