Remarkable Scientist

Louis Pasteur is one of the most remarkable names in the field of medicine. From a humble beginning, he grew up to make extraordinary contributions to society, including the vaccines for rabies and anthrax, and the processes of Pasteurization and Sterilization. His love for science stemmed from everyday problems that people faced regularly.

Published Categorized as Biography
Louis Pasteur in his laboratory; leaning on the work table which has chemicals and apparatus
“Do not let yourself be tainted with a barren skepticism.”

Last Updated on April 16, 2021

Louis Pasteur (1822 – 1895) – Microbiologist, Chemist

Louis Pasteur was born on December 27, 1822, in Dole, Jura, France. He came from a long line of tanners. The men in his family made leather from animal hides to provide for their families. Louis was the third child of Jean-Joseph Pasteur and Jeanne-Etiennette Roqui.

Louis entered preparatory school in 1831, where he received honors and attended secondary school in Collège d’Arbois. In his earlier years, Louis was an average student, not exerting much effort in academics but was interested in arts. Unbeknownst to many, Louis was a gifted artist who often made sketches or portraits of his family and friends.

At the age of 16, Louis tried to go to Paris to study but only lasted a month due to his homesickness. In 1839, he was accepted in Collège Royal at Besançon, where he studied philosophy and graduated with a Bachelor of Letters on August 29, 1840.

At Besancon, Louis first encountered France’s first and greatest chemist, Jean-Baptiste Dumas, and was captivated by his teaching style. It was because of Dumas that Louis decided that he wanted to pursue higher studies in École Normale Supérieur, a prestigious school in Paris. It was founded by Napoleon Bonaparte to train teachers.

Louis knew that he needed to earn his baccalauréat in science, so he decided to extend his stay in Besançon to take up a teaching position as a substitute to help with his finances while preparing for his exams. He was living his life as if he had already achieved a lot and was ready to take any challenge.

Unfortunately, Louis failed his exams in 1841. It did not stop him from working hard, though, and at 19, he returned to work and became more in touch with reality. While he attended his classes in Collège Saint-Louis, he continued teaching mathematics to students in the lower grades.

Louis excelled in his science lessons this time around, particularly in physics, and was eventually admitted to École Normale Supérieur in October 1843. Louis Pasteur’s hard work in studying, substitute teaching, and research paid off when he earned his master’s degree in 1845 and doctorate in 1847.
A year after his graduation, he left Paris to teach science in Dijon, France, in a lycée and at the University of Strasbourg. While he was there, he met Marie Laurent, daughter of one of the clergies in school. Pasteur married her on May 29, 1849 and had five children. Only two kids reached adulthood.

Pasteur began to gain prestige in the field of science. At age 26, Pasteur coined the term, stereochemistry, whereby he explained how atoms could join together to form molecules. In 1854, Pasteur had his breakthrough when he proved that the fermentation process was brought about by living microorganisms.

Pasteur was working at the University of Lille when he discovered that local businesses had manufacturing problems because their beer and wine were spoiled due to the fermentation. Pasteur thoroughly studied samples he got from the fermented liquids and found out that there were two microorganisms present in the said process; a yeast that can produce good alcohol and lactic acid that harms the wine and beer.

Louis Pasteur, standing, holding eyeglasses, with chemical apparatus and books. In his left lapel Pasteur wears the badge of the Légion d'Honneur
Lettering on a notice in the background honours Pasteur for his work on rabies.

He demonstrated to the public that heating the wine at medium temperature would kill the microorganisms that cause the products to go bad. The process was named pasteurization, after Louis Pasteur, and is still used today to help in the purification of most of our drinks including water and milk.

Pasteur also studied butyric acid fermentation, where he defined that aerobic organisms is the type of life form that requires oxygen to live. On the other hand, an anaerobic bacterium is an organism that does not need oxygen to survive and, through glycolysis, could oxidize sugar and, at times, pectin. Pasteur also noted that anaerobic microorganisms were responsible for the putrefaction process.

Pasteur introduced the germ theory in 1859, debunking the spontaneous generation hypothesis which was supported by some of the most brilliant scientists at the time.

According to spontaneous generation, living organisms can appear in dead matter. Louis Pasteur studied the hypotheses and decided he needed to pursue the debate. He conducted an experiment wherein he put samples of spores in a sealed flask and as a control group, he also placed samples into an uncovered one.

He discovered that the spores placed in open containers multiplied, but those in sealed containers remained the same. Pasteur repeated this experiment by boiling two batches of beef broth in a long-neck flask that filtered the dust that allows the microorganisms to grow. After boiling, he took off the filter of one vial and it immediately became infected with bacteria. Pasteur’s experiments regarding the germ theory were verified by several scientists which included Jean-Baptiste Dumas, Pasteur’s professor and mentor in chief.

In 1865, the French government asked for his help in discovering the disease that had ravaged the silkworm population, putting the silk industry at risk. Pasteur, though he was apprehensive about accepting the challenge, still sought out the cause of the problem with aid from Dumas.

Within a few months, he was able to pinpoint the cause. He told the government to destroy all existing silkworms and their eggs as soon as possible since they were already contaminated. They quickly accepted his proposal and began breeding new batches of silkworms again. This successful endeavor added to Pasteur’s fame, and the people were grateful to him for saving their livelihoods.

Together with his recent successes, Pasteur experienced deaths in the family; his father, his two-year-old and 12-year-old daughters all died within a few days. He left his teaching post at the École des Beaux-Arts and started residing at École Normale as Director of Scientific Studies in 1867.

Pasteur was 46 years old when Emperor Napoleon III awarded him a research laboratory so he could continue his research. Pasteur worked so hard that in 1868, he suffered a stroke, paralyzing the left side of his body and he had to rely on others to do ordinary tasks.

In the Franco-Prussian War in 1870-1871, Pasteur tried enlisting in the army but was told to go back to his research laboratory. He then devoted his time to advice the army that since microbes are the leading cause of infections, the surgical tools should be sterilized before treating the wounded.

Again, Pasteur proved to be working wonders and became part of the French Academy of Medicine. In addition to this great honor, the wine and beer industries published his studies from 1866-1876. He offered his help in brewing wines and beers to the French sector and developed a more meticulous way to kill germs that threaten the purity of the liquids.

After the sterilization of the medical paraphernalia and brewing projects, Pasteur turned his focus to developing vaccines for diseases which had threatened the lives of both animals and human beings.


“Science knows no country, because knowledge belongs to humanity, and is the torch which illuminates the world.”

Louis Pasteur

Around 1879, he discovered that anthrax was killing off France’s cattle and immediately dived into research on how to go about this situation. Pasteur drew his inspiration from Edward Jenner, an English doctor who began the process of immunization.

Pasteur thought of following Jenner’s example, where he immunized people with small doses of cowpox for them to develop resistance to smallpox. Pasteur decided he could do something similar to this, and so, in 1881, Pasteur devised a way to boil anthrax germs to weaken them.

He also wanted to try out his experiment the way he did with germ theory. He injected just one batch of cattle with the concoction he made, and later injected the two batches with stronger anthrax. Just as expected, the cattle that were injected with the lighter dose of anthrax survived as opposed to the batch that did not receive the first injection.

He applied the same process to chicken suffering from cholera and was also successful in doing so. The farmers were more than grateful to Pasteur as he saved their fowl. More than that, the French government showed their appreciation by giving Pasteur constant finances for his research and experiments.

When Pasteur was 60 years old, he researched on the treatment for rabies, observing that an extraordinary number of people suffered a slow and horrible death. He risked getting samples of the saliva from rabid dogs and injected it to rabbits.

Pasteur extracted some liquid from the rabbits’ spinal cord and injected these samples to other test animals, discovering that it had somehow neutralized the deadly germs. He wondered how the human body would react, and the opportunity to find out came in July 1885, when Joseph Meister, a nine-year-old kid was bitten fourteen times by a rabid dog.

At first, Pasteur was reluctant to try the vaccine because of a lot of negative factors, but the urgency of the matter and his curiosity won him over. He gave the boy a daily dose of vaccine, one stronger than the next, until the boy fully recovered.

Photograph after a painting by Jean-André Rixens. Louis Pasteur acclaimed amidst a dignified crowd
Joseph Lister, Baron Lister acclaims Louis Pasteur at Pasteur’s Jubilee, Paris, 1892

It was a victorious moment for Pasteur. He also helped save several people who were bitten by an infected wolf. On November 14, 1888, the President of France inaugurated The Pasteur Institute, and Pasteur, who was at loss for words, asked his son to deliver his speech for him. Scientists and doctors alike celebrated Pasteur’s seventieth birthday in Sorbonne and honored his brilliant research and experiments. Pasteur’s health was already declining, and his age was catching up to him.

On September 28, 1895, he died and was given a state funeral. He was given the highest regard; his body being buried under The Pasteur Institute and his tomb decorated with paintings of people and animals.

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