Widely considered one of the most brilliant scientists in history, Louis Pasteur basically revolutionized the world as we know it. His breakthroughs have saved countless lives and improved the quality of life for people worldwide, and his work paved the way for what we call today microbiology. We owe him a lot, at the very least knowing the things he did to change the world:
- Germ Theory of Diseases
For most people, Pasteur is remembered for his studies on pasteurization, a word dubbed after him, but before he could demonstrate pasteurization, he needed an extra tool – the germ theory of diseases. For most of the medieval times, the prevalent theory regarding illnesses was the miasma theory. The miasma theory claims that diseases such as cholera, chlamydia or the plague were caused by a miasma – a noxious bad air.
In the 1800s, people started questioning that, and some scientists (like John Snow) started writing essays about their observations regarding the invalidity of miasma theory. However, it was Pasteur that first proved that germs make us sick. He found not only that microorganisms can make us sick, but he also wrote recommendations on how to kill them and protect ourselves.
In order to support his theory, he exposed freshly boiled broth to air in vessels that contained a filter to stop all particles from going through. Nothing grew inside the broths, so it was clear that the things that usually grow in such broths come from outside.
Pasteurization is what Pasteur is chiefly known for today – hey, if they named a word after him, it’s pretty obvious that it’s something big. Having previously demonstrated that microorganisms cause not only diseases, but can also cause foods to ferment and go stale, he figured out that by heating beer or wine, he could prevent them from turning sour. This was achieved by eliminating pathogenic microbes and lowering microbial numbers to prolong the quality of the beverage.
This is not complete sterilization – wiping out all the microorganisms – but rather reducing the number of pathogens up to the point where it’s very unlikely that the food or drink turns sour. This process is still widely used today, especially for dairy products and beers. So if you like milk or beer, you have Pasteur to thank.
- Saving European Silk Industry
While he was working on the germ theory, Pasteur also had another major accomplishment: he found that a serious disease of silkworms, pebrine, was caused by a small microscopic organism now known as Nosema bombycis. French silk industry was already seriously affected, and the disease was starting to spread to other areas as well.
Pasteur saved the silk industry in France by developing a method to screen silkworms eggs for those that are not infected – and the method is still used today.
- Immunology and Vaccination
As the man that finally proved how dangerous germs can be, Pasteur felt responsible to do as much as possible to fight diseases. His later work on diseases included work on chicken cholera. After a rather strange series of events which included his assistant going on vacation and not doing the work he was supposed to do, Pasteur figured out that he accidentally found a way to develop a vaccine.
The notion of a weak form of a disease causing immunity to the virulent version was not new, but Pasteur wanted to develop it for things like anthrax and cholera. Unfortunately, historical records now show that he took credit for something that wasn’t his – he used the method of rival Jean-Joseph-Henri Toussaint, a Toulouse veterinary surgeon, to create the anthrax vaccine. Toussaint never received credit for his work.
So if you read somewhere that Pasteur developed an anthrax vaccine… there’s at least another side to that story – it’s one of science’s great injustices. But this doesn’t take away his other contributions to immunology and vaccination.
- The Pasteur Institute
Pasteur founded an institute to carry on his legacy and continue his research. Today, the Institut Pasteur is one of the world’s leading research centers; it houses 100 research units and close to 2,700 people, including 500 permanent scientists and even more visiting scientists.
Among the achievements of scientists working at the institute is a better understanding of diphteria, a disease that used to kill thousands of children each year, an antituberculosis vaccine, a typhoid vaccine, and many other important achievements.
These are just some of the events for which Louis Pasteur, the brilliant scientist is revered today. His life wasn’t always glamorous, and he had his fair share of controversy – but he remains one of the most brilliant scientist, and mankind has many to thank him for.
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