If I was to choose among the greatest benefactors of humanity, Louis Pasteur would certainly be up there at the top. Louis Pasteur has solved mysteries of rabies, anthrax chicken cholera and silkworm diseases, and contributed to the development of the first vaccines. He debunked the widely accepted myth of spontaneous generation, thereby setting the stage for modern biology and biochemistry. He described the scientific basis for fermentation, wine-making, and the brewing of beer.
His work gave birth to many branches of science. His discovery that most infectious diseases are caused by germs known as the ‘germ theory of disease’ is one of the most important in medical history. His work became the foundation for the science of microbiology. He championed changes in hospital practices to minimise the spread of disease by microbes. He also discovered that weakened forms of a microbe could be used as an immunisation against more virulent forms of the microbe. Another highly beneficial discovery is that he found out rabies were transmitted by agents so small they could not be seen under a microscope, thus revealing viruses.
As a result he developed techniques to vaccinate dogs against rabies, and to treat humans bitten by rabid dogs. Pasteur also developed ‘pasteurisation’, a process by which harmful microbes in perishable food products are destroyed using heat, without destroying the food. He did this by going to a vineyard in Artois in 1864 to study this problem. He demonstrated that wine diseases are caused by micro organisms that can be killed by heating the wine to 55 degrees Celsius for several minutes. Applied to beer and milk this process, soon came into use all over the world. Pasteur also laid rest the theory of ‘spontaneous generation’.
The Term Paper on Communicable diseases
95 Infectious agents and examples of diseases The organisms that cause disease vary in size from viruses, which are too small to be seen by a light microscope to intestinal worms which may be over a metre long. The groups of infectious agents are listed with examples of diseases they cause. Bacteria Pneumonia, tuberculosis, enteric fever, gonorrhoea Viruses Measles, varicella, influenza, colds, ...
John Needham and English clergy man in 1745, proposed what he considered as the definitive experiment. Everyone knew boiling kills micro organisms, so he proposed to test whether microbes appeared spontaneously after boiling. He boiled chicken broth, put it into a flask, sealed it and waited- sure enough microbes grew. Needham gained victory for spontaneous generation. However L azzaro Spallanzi was not convinced and he suggested that perhaps the micro organisms had entered the broth by air after the broth boiled, but before it was sealed. To test this theory, he modified Needham’s experiment- he placed the chicken broth in the flask, sealed the flask, drew off the air to create a vacuum, and then boiled the broth.
No micro organisms grew. Proponents of spontaneous generation argued that Spallanzi had only proven that spontaneous generation could not occur without air. In 1859 Pasteur did a winning experiment which was a variation of Needham’s and Spallanzi’s. He boiled meat broth in a flask, heated the neck of the flask in the flame until it became pliable, and bent it into a shape of an ‘s’. Air could enter the flask, but airborne organisms could not they would settle by gravity in the neck. As Pasteur expected no organisms grew.
When he tilted the flask so that the broth reached the lowest point in the next, where any airborne particles would have settled, the broth rapidly became cloudy with life. Pasteur both disproved the theory of spontaneous generation and convinced that micro organisms are everywhere- even in air. Louis Pasteur was a humanist, always working to the improvement of the human condition. He was a free man who never hesitated to take an issue with the prevailing yet false ideas of his time. All of his achievements point to a singular brilliance and perseverance in Pasteur’s nature. He has protected millions of people from disease through his amazing work..
The Essay on Chameleons Organism Physiology
We know that an organism is anything that is living and can function by itself. This paper will help understand chameleons and how they have evolved to adapt to their surroundings. It will also discuss their physical features inside and out. Myths and facts will be revealed, as well as a few comparisons between sexes. Though there are many species of chameleons, everything discussed will be in ...
