Saturday, October 26, 2019

Lazzaro Spallanzani :: essays research papers

Lazzaro Spallanzani Lazzaro Spallanzai, was the Italian physiologist who was one of the founders of experimental biology. Born in Scandiano, a small town in the providence of Emilia on Jan. 12, 1729 , Spallanzani was among the many dedicated philosophersof the eighteeth century (Lazzaro...1). His main scientific interests were biological and was a master at mircoscopy,but he also looked into problems of physics,chemistry, geology, and meteorology, and volcanology (Gillispie,1). After attending a local school, Spallazani went at afe fifteen to a Jesuit seminary in Reggio Emilia where he dominated in rhetoric, philosophy, and languages. He left Reggio Emilia in 1749 to study jurisprudence at the ancient University of Bologna, where he expanded is education in mathematics, chemistry, natural history, and aquired a knowledge of French (Asimov,1). For three years he worked toward his docterine in law. In 1753 or 1754 he became a doctor of philosophy. Then, he recieved instructions in metaphysics and theology and took minor orders. Within a few years he became a priest and added himself to two congregations in Modena (Gillispie,2). Spallanzani, in hundreds of experiments tested various rituals for rendering infusions permanently barren and finally found that they remained free of microorganisms when put into flasks that were sealed and the contents boiled for one hour (Lazzaro...1).The entrance of air into the flask through a slight crack in its neck was Patel 2 followed infusoria. He reported no spontaneous generation in strongly heated infusions protected from aerial contamination. In 1765, after cutting up thousands of earthworms and exploiting the ability of the aquatic salamander to regrow its tail, he resolved to investigate reproductive phenomena in animals ans plants(Gillispie,3). He proved this by cuting theworms the area that affected the segmental regenerative response. Amputation of the tailwas followed by vascularization of the transparent growing stump. He also established the general law that in susceptible species inverse ratio obtains between the regenerativecapacity and age of the animal. Lazzaro launched countless experiments relating to infusion animalcules and "spermatic worms," with result that soon made chimera of thevegetatice force and undermined the docterine of organic molecules; but these ideasdemanded more attention so they were postponed (Asimove,2). He also found that complex infusoriaare more susceptible to heat and cold than the "infinitely minute" germ of lower class,whose relative resistance he ascribed to their eggs. In 1777 he publicly demonstrated the great force exerted by the gizzards of fowls and ducks in

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