I. Introduction
Figure 1: Louis Pasteur
Born the son of a tanner, no one ever expected Louis Pasteur to become the incredible scientist that he was. At the time he was born, the world was convinced that germs spontaneously generated from rotting flesh. Most diseases were life threatening. By the time of his death, Pasteur helped to prove that germs were in fact living things that lived everywhere, infecting things available to them. He developed many vaccines to harmful viruses, including rabies and anthrax. He studied and learned the causes of the diseases of animals and humans alike. He created the process known as pasteurization. And perhaps most importantly, he helped to develop the Germ Theory of Disease, which remains to this day one a valid and almost unanimously accepted theory on how diseases are acquired and how they may be cured.
II. Pasteur's Discovery
Figure 2: Swan Neck Duct
In one of his most famous experiments, Pasteur attempted to disprove spontaneous generation of life. Pasteur filled to swan neck ducts with a broth and sealed the end of the necks so that no air could enter. He then broke the neck of one of the flasks. Upon examination, the neck of the flask that was sealed had no microbes in it, while the one he had exposed to the air did. These results allowed him to prove that microbial life comes from natural growth. Armed with this knowledge, Pasteur thought that these microbes could be the cause of many infectious diseases. Pasteur began experimenting with chickens. He introduced the viruses which cause cholera that he collected into the chickens' bloodstream. These chickens soon died, while others who were unaffected, did not. Upon further tests, Pasteur was able to show that many diseases, such as anthrax, could be caused in the same way. Using this to build upon the work of other scientists, Pasteur was able to give weight to the germ theory of disease, which says that microbes, such as bacteria and viruses, are the cause of diseases.
III. Louis Pasteur: The Man Himself
Louis Pasteur was born on December 27, 1822 in Dole, France. Born in a poor family, Pasteur was interested in science from an early age. He planned to attempt to find out about the nature and origin of life and the structure of matter. Like the great scientists of previous centuries that he admired, Pasteur always searched for knowledge with vigor, trying to understand the mysteries of the world. He became first a professor of physics and later a professor of chemistry at the University of Strasbourg. In 1849 he married Marie Laurent. Three of their five children died of typhoid, which drove him later to cure diseases. As a chemist, he discovered the nature of tartaric acid and wrote a thesis on crystallography. One of his first great feats in microbiology was his discovery that fermentation was caused by microbes. This was followed by his disproving of spontaneous generation. Using these discoveries, he helped to pioneer the germ theory of disease, developing theses and performing experiments that supported it. Another achievement was the creation of pasteurization, in which he heated milk to kill bacteria. He later worked on curing diseases, including those that were killing colonies of silkworms and sheep. His later work allowed him to create vaccines by exposing weakened bacteria to a patient, immunizing them to the virus. He developed vaccines for both rabies and anthrax. The scientist finally died on September 28, 1895 from complications of stroke.
IV. Impact on the World
The germ theory has been proven to be correct. It is the most widely accepted reason for disease. Thanks to Pasteur's work, bacteria and viruses were heavily researched, and their true nature and function was revealed. How they cause disease is now generally understood, and because of that, many of the diseases that they cause can now be prevented. Pasteur and many other later scientists and doctors, created many vaccines and antibiotics that work to fight off infection and kill harmful microbes. Diseases like rabies, anthrax, cholera, dysentery, typhoid, polio, influenza, and many other diseases are treatable and curable. Thanks to Pasteur's contributions, the length of life in the western world has greatly extended, and medicine as a whole has leaped forward immensely since his death.
V. Journal Analysis
The Attenuation of the Casual Agent of Fowl Cholera
Louis Pasteur, 1880
Published in the Comptes Rendus de l"Academie des Sciences, October, 1880
Published in 1880, Pasteur stated a thesis about the cause of cholera in chickens. The bacterium which causes the disease, Pasteurella multocida, brings about multiple symptoms in the fowl before causing it to die. A particular strain of this disease can take several months to kill an individual fowl. Upon observing this. he experimented by introducing this strain to a chicken. Over a length of time, the chicken would die. He would extract the disease and inject it into another individual. After repeating this process multiple times, he noted that the severity of the virus decreased, until the chickens infected began to recover. The bacteria could then be used as a vaccine as he called it (truly an antibiotic). It was in this way that Pasteur developed vaccines.
VI. References
1. Dubos, R.J. (1950). Louis Pasteur, Free Lance of Science (1st ed.) Boston: Little, Brown.
2. Pasteur, Louis. (1880). The Attenuation of the Casual Agent of Fowl Cholera. Comptes rendus de l'Academie des sciences , vol. 91.
3. Robbins, L. E. (2001). Louis Pasteur: And the Hidden World of Microbes. New York: Oxford University Press.
Figure 1: http://www.en.wikipedia.org/wiki/File:Louis_Pasteur_by_Pierre_Lamy_Petit.jpg
Figure 2: http://www.en.wikipedia.org/wiki/File:Coldecygne.svg
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