- Invention of microscope in 1673 by Antoni Van Leewenhook made it possible to view the small creatures that existed,which were expected long before.
- During 300BC,Aristotle believed that organisms might have originated spontaneously from the soil,plants or others.
- About 40BC,Virgil gave directions for the artificial propagations of bees.
- During this period it was an accepted fact that maggots might have developed by exposing meat to warmth and air, but Francisco Redi doubted this fact. For which he experimented and gave his view that maggots originated from flies and not the meat.Which undoubtedly settled the controversy of spontaneous generations.
- In 1749 John Needham observed the appearance of organisms on meat exposed to hot ashes that were not present at the start of the experiment and concluded that bacteria originated from the meat.
- In the 17th century L.spallanzi kept the boiled beef in the flask which was sealed,which showed no microbes.And this discouraged spontaneous generation.
- Edward Jenner in 1798 succesfully demonstrated vaccination.Due to this contribution most of the industrialized world was free of smallpox.
- After some 60 years,this was again answered by two scientists Schulze and Schwann.
- Both the scientists passed air through strong acid and red hot tubes separately into the flask.In neither of the cases,microbes appeared.But taught that acid and heat changed the air,so cannot support growth.
- Similarly in 18th century scientists like Schroeder,T.Von Du sch and Poucher gave their own view about the spontaneous generation.
- Irritated by the Pouchet’s logic and data,that gave an extensive report that proved its occurrence,Louis Pasteur performed the experiment that ended the argument for all time,and proved that microorganisms are not spontaneously generated from inanimate matter.
- And in 1877,John Tyndall gave final blow to spontaneous generation.
- A fascinating and fortunate accident for the discovery of wonder drug penicillin was the major contribution of Sir Alexander Fleming of England 1929.
Friday, September 17, 2010
Posted by milan at 1:01 AM