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Wednesday, 4 January 2017

Louis Pasteur


Louis Pasteur was born on December 27, 1822, in Dole, Jura, in the French Jura mountains.

His father, Jean Joseph, was an ex Napoleonic soldier and a tanner. Louis' mother was Jeanne Pasteur and he had three sisters, Virginie, Josephine, and Emilie Pasteur. Emilie had a sickness that froze her mind and even though she grew to adult size she still had the mind of a five-year old.

Louis' childhood was spent among the vineyard covered slopes of the Jura mountains. His chief interest and talent lay in painting and he also enjoyed fishing.

When Louis was four, he and his family moved to nearby Arbois, where his father established a tannery.

Between 1829-39 Louis attended schools in Arbois where he was a hardworking but mediocre pupil.

In 1839, he entered the Collège Royal de Besançon and earned his baccalauréat (BA) degree in 1840 and Bachelor of Science degree two years later.

Pasteur passed the entrance exam for entry into the École Normale Supérieure (a higher education establishment in Paris) in 1842, but was so disgusted at coming 14th that he retook the exam and came fourth.

In 1843 Louis started at the École Normale Supérieure where he earned his Master of Science Degree and later earned his Advanced Degree in physical sciences. In 1847, Louis Pasteur earned his Doctorate in Sciences.


After Pasteur was awarded his doctorate he took up a post as assistant to the chemist Jean-Baptiste-André Dumas, one of his teachers at his alma mater Ecole Normale. Pasteur's first major contribution to chemistry occurred during this time, with his dissertation on the new field of crystallography, the study of forms and structures of crystals.

Pasteur was a Physics teacher at a High School in Dijon in 1848, but he only lasted three months.

In 1849, Pasteur was appointed Professor of Chemistry at Faculty of Sciences in Strasbourg. He made himself popular with his electrifying lectures.

Pasteur developed such a reputation, that in 1854, aged just 32, he became Dean of the Faculty of Science at the University of Lille. He began there his studies on fermentation. Through his experiments, he discovered yeast and disproved the old theory of spontaneous generation that lower animals were created from putrefaction.

Pasteur sought no profits from his discoveries and supported his family on his professor’s salary or later on a modest government allowance.

In 1857, Pasteur was selected to be the Director of Scientific Studies at the École Normale Supérieure where he served till 1867. Both students and staff found him to be authoritarian, inflexible and overpowering and he resigned in 1867.

In 1867 Pasteur was appointed Professor of Chemistry at Sorbonne. At the Sorbonne Pasteur showed the audience lantern slides of different germs then he darkened the hall and shot a single bright beam of light through the blackness revealing the specks of dust that sometimes carried diseases, cholera, yellow fever etc. The audience went home very concerned.

In 1887 Pasteur established the Pasteur Institute and served as its director for the rest of his life. A year after its inauguration, the institute started the first course of microbiology ever taught in the world, then titled ‘Cours de Microbie Technique’


During Pasteur's time, people believed that microbes such as bacteria appeared due to "spontaneous generation." They thought that the bacteria just appeared out of nowhere. Pasteur ran experiments to see if this was true. Through his experiments he proved the existence of airborne bacteria, identified and produced germs and introduced the science of microbiology. He also showed that germs could be killed by filtration, heat and the use of antiseptics. His experiments earned Pasteur the nickname the "Father of Germ Theory."

In the early 1860s, people had thought it was chemical changes that made milk "go off" and spoil other beverages. Pasteur's research showed that the growth of micro-organisms was responsible for spoiling drinks. With this established, he invented a process in which the beverage was heated killing the bacteria present in it without destroying its food value. The first pasteurization test was completed by Pasteur and Claude Bernard on April 20, 1862.

Pasteur experimenting in his laboratory.

Pasteur's discoveries vastly improved the taste of French wine. Some local wine makers had been complaining that their crushed grapes tasted vinegarish. During a 1864 summer holiday in Arbois, Pasteur performed experiments in an improvised lab in the back room of a café. He discovered that by heating a young wine to about 50–60 °C (122–140 °F) for a brief time to kill the living organisms that sour the drink, the wine could subsequently be aged without sacrificing the final quality. Pasteur's improvements in the preparation of French wine created a rapid increase in their sales.

Pasteur patented the method, which in honor of the chemist became known as pasteurization in 1865.

Louis Pasteur's intense nationalism inspired him to investigate why German beers were superior to French ones. The explanation was similar to the earlier problem he encountered with wine in that he found micro-organisms were ruining the French ones.

Pasteur devised a new microbiological procedure for brewing beer that improved the taste of French beer and enabled it to preserve its taste for a longer period. This meant the French would be able to export their beer to their colonies without it deteriorating on the long journey en route.

Pasteurization was originally used as a way of preventing wine and beer from souring and it would be another two decades before milk was pasteurized.

Pasteur's pioneering work on pasteurization paved the way for medical breakthroughs such as Joseph Lister's antiseptic treatment of surgical wounds. Lister said of the French chemist. "There does not exist in the wide world an individual for whom medical science owes more than to you."

In 1874 Pasteur suggested placing surgical instruments in boiling water and passing them through a flame as an antiseptic.

By the mid-1860s, the silk industry in France was being ruined by disease attacking the silk worms. Pasteur worked on this problem for six years. His solution on locating a tiny parasite that was infesting silkworms and the mulberry leaves that were fed to them was drastic: Destroy all infected worms and infected food. This was done and the silk industry was saved.

Pasteur correctly theorized that the body had an immune system that would fight internally against sickness and helped start off investigations into this. His first important work in the field of vaccination came in 1879 while studying a disease called chicken cholera. Pasteur accidentally left on his lab bench a sample of bacterial fluid, which infected the chickens. On his return he found the culture of growing bacteria was weakened and found it an ideal inoculation against cholera.

Pasteur researched the cattle and sheep disease Anthrax and in 1881 he developed a vaccine for the ailment. He reduced the mortality rate to 1% in sheep and one third of 1% in cattle.

Pasteur developed a vaccine against rabies after five years of investigation. A nine years old shepherd boy, Joseph Meister, who had been bitten by a mad rabid dog, was the first to be inoculated on July 6, 1885. He made an amazing recovery and soon Pasteur's surgery was besieged with rabid victims.

Louis Pasteur in his laboratory, painting by A. Edelfeldt in 1885


Pasteur was extremely right wing and nationalistic. His ideas about bacteria were closely related to his hatred of the masses. An ardent patriot, Pasteur was zealous in his ambition in making France great through science.

Louis Pasteur remained throughout his whole life an ardent Christian. However, despite his belief in God, it has been said that his views were that of a freethinker rather than a Catholic, a spiritual more than a religious man. He was also against mixing science with religion.


Pasteur wore glasses, he was extremely short-sighted.

Studio portrait of Louis Pasteur, 

He had a fear of dirt and infection. Pasteur refused to shake hands and carefully wiped plate and glass before dining.

Pasteur had a bulldog-like perseverance and tenacity, he was a calm and exact worker.

Pasteur was not an adventurous eater: Every Thursday he consumed hot sausage garnished with red kidney beans, the other six days of the week he had a mutton cutlet with sautéed potatoes.


Pasteur married Marie Laurent, the daughter of a local university rector at Strasbourg on May 29, 1849.

Marie worked as her husband's active assistant in his scientific experiments and also served as his secretary.

The couple had five children, but only two of them survived to adulthood. The other three died of diseases: Their eldest daughter, Jeanne, died from typhoid fever, aged 9, at Arbois. Then, in 1865, 2-year-old Camille also died of typhus, followed by 12-and-a-half-year-old Cécile in 1866. These personal tragedies strengthened Pasteur’s resolve to find cures for infectious diseases.

Only Jean Baptiste and Marie Louise lived to be adults. Jean Baptiste would be a soldier in the Franco-Prussian War between France and Prussia and later became a diplomat.


Pasteur was permanently paralyzed on his left side by a stroke in 1868. He was still mobile though one foot dragged a little as he walked. The stroke came as a result of the strain of the death of his father and twelve-year-old daughter. As a result, he had to rely upon assistants to perform his experiments though he could still use a microscope.


Louis Pasteur died on September 28, 1895 near Paris from complications caused by a series of strokes that had begun plaguing him as far back as 1868. He was buried in the Cathedral of Notre Dame, but his remains were soon placed in a tomb of marble and granite under the courtyard of the Institut Pasteur, Paris.

Sources Thefamouspeople.comHarraps Book of Scientific Anecdotes, The Alarming History of Medicine by Richard Gordon

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