Hero of Science: Savior of Milk and Wine (also children), Louis Pasteur

You’ve probably heard of the 19th Century scientist Louis Pasteur – he invented the process that now carries his name, pasteurization. By heating food or drink, most of the microbes that cause spoilage or disease are killed, which means that the food and drink can last a lot longer. Pasteur originally applied this to wine, but it’s now applied to beer, milk, fruit juices and canned food. At first glance, it might not be immediately obvious how beneficial this is, but pasteurization is not the main reason that Pasteur is one of Biology Badger’s all time heroes. Pasteur proved that microorganisms do not spontaneously appear out of nothing, and contributed to the germ theory of disease. He worked out how fermentation to produce alcoholic drinks worked, and he discovered the processes to create some of the first vaccines. Finally, he put all his work and reputation on the line to try and save the life of a child.

Although heating food to make it keep longer had been tried previously, it was done so at too high temperatures and for too long, changing the food or drink for the worse in the process. Pasteur invented his own method for wine while he was on holiday. Given that milk is one of the most perfect things for bacteria to grow in – including the bacteria for several nasty diseases – pasteurization is critical if we want to continue drinking it!

In the 19th century, it was still believed that microorganisms appeared spontaneously as food spoiled. Pasteur proved this wrong with a very elegant experiment in which he prepared two “swan-necked” flasks, which prevented dust and bacteria reaching the sterile broth within but still allowing air through. When tipped so the dust contacted the broth, the result was growth – so the bacteria must be coming from the dust in the air and not spontaneously appearing!

NB: Biology Badger suggests that one of the above is safer to handle than the other, and far better at catching bacteria in the neck.

Pasteur also discovered a critical factor for developing vaccines. He had an experiment in which a culture of bacteria failed to make some chickens sick; when he tried again with new culture, the fresh bacteria still couldn’t affect the chickens. The “weakened” bacteria had made the chickens immune without making them sick. He used this technique, making diseases weaker to provide immunity, to develop an anthrax vaccine.

It wasn’t until later, when a famous scientist, he was approached by a distraught mother whose son had been bitten by a rabid dog – a certain death sentence from a horrible disease.

Pasteur and his close colleague Emile Roux, who had been working on a rabies vaccine, agreed to give it a try. Joseph Meister, the 8 year old boy, was inoculated with the experimental vaccine. This was a big risk for Pasteur – technically he was breaking the law, as he was not a medical doctor; if the boy died at the very minimum his career, and possibly freedom, would have been curtailed.

Emile Roux and his mighty beard.

It is for this bravery, in risking a lifetime’s accomplishments and reputation for the chance to save a life, for which Biology Badger commends Pasteur as a Hero of Science.

The vaccine seems to have worked; Joseph never developed rabies and went on to live a normal life, working at the very institute named for the man who saved him. Legends always follow heroes; an often told one is that when Paris fell in world war 2, Nazi soldiers demanded access to Pasteur’s tomb. The gatekeeper, Joseph Meister, killed himself rather than allowing it. Like a lot of legends, this turns out not to be true, but still demonstrates the monumental impact Pasteur made in his life.

Louis Pasteur and Joseph Meister