development of the octopuses, and squids are truly remarkable. He also contributed towards the scientific development by introducing diagrams for illustrating complex anatomical relations.Almost 2000 years later Galileo challenged Aristotles s work on mechanics and cosmology. Galileo did not ridicule Aristotle, but simply showed that he had jumped to the wrong conclusions and derived at inadequate answers because of his physics being not very mathematical. Errors in Aristotles work were rectified through direct observation and by the availability of new instruments and experimentation techniques in the 17th century. Amongst other contributions, Galileo contradicted Aristotles view that bodies naturally returned to their natural place. It is believed that Galileo demonstrated by throwing different weights from the Leaning Tower of Pisa that the weight of the bodies was irrelevant to their speed of falling and only the density of the medium counted.Lavoisier interpreted facts discovered by others and corrected them for errors. He is considered the father of chemistry although he discovered no new chemical substances apart from a few new chemical facts. Lavoiser used to carry out a lot of experiments, quantify their results and take various precautionary measures. He studied Stahl`s theory on combustion and found errors in reasoning. Stahl had given the concept phlogiston for combustion but Lavoiser proved that no such thing existed. Lavoisier repeated Boyle`s experiments which had showed an increase in the weight of cal of tin when tin was calcined in a closed glass vessel. By sealing the vessel during the experiment and taking careful readings Lavoisier proved the law of conservation of mass which says that an equal amount of matter exists before and after every operation.Pasteur is primarily responsible for establishing the germ theory of disease. He carried out an astonishing variety of experiments involving microorganisms, which lead...
