Amalgam (dentistry) and 900 shares of tin." Ever since its introduction in the Western world in the 1830s, amalgam has been the subject of recurrent controversies because of its mercury content. Early amalgam was made by mixing mercury with the filings of silver coins. In 1833 Englishmen, Edward Crawcour and his nephew Moses Crawcour (incorrectly referred to as "the Crawcour brothers"), brought amalgam to the United States, and in 1844 it was reported that fifty percent of all dental restorations placed in upstate New York consisted of amalgam. However, at that point the use of dental amalgam was declared to be malpractice,
Women in chemistry the only woman to be award two Nobel prizes). Her prize in chemistry was for her "discovery of the elements radium and polonium, by the isolation of radium and the study of the nature and compounds of this remarkable element." Irene Joliot-Curie, Marie's daughter, became the second woman to be awarded this prize in 1935 for her discovery of artificial radioactivity. Dorothy Hodgkin won the prize in 1964 for the development of protein crystallography. Among her significant discoveries are the structures of penicillin and vitamin B12. Forty five years later, Ada Yonath shared the prize with Venkatraman Ramakrishnan and Thomas