<Tr> <Td> </Td> <Td> This article's lead section does not adequately summarize key points of its contents . Please consider expanding the lead to provide an accessible overview of all important aspects of the article . Please discuss this issue on the article's talk page . (June 2018) </Td> </Tr> <P> A Stradivarius is one of the violins, violas, cellos and other string instruments built by members of the Italian family Stradivari, particularly Antonio Stradivari (Latin: Antonius Stradivarius), during the 17th and 18th centuries . According to their reputation, the quality of their sound has defied attempts to explain or equal it, though this belief is disputed . The fame of Stradivarius instruments is widespread, appearing in numerous works of fiction . </P> <P> Stradivari made his instruments using an inner form, unlike the French copyists, such as Vuillaume, who employed an outer form . It is clear from the number of forms throughout his career that he experimented with some of the dimensions of his instruments . The woods used included spruce for the top, willow for the internal blocks and linings, and maple for the back, ribs, and neck . </P> <P> There has been conjecture that the wood used may have been treated with several types of minerals, both before and after construction of a violin . Scientists at National Taiwan University have detected trace amounts of aluminum, copper, and calcium in wood from Stradivari violins . The traces may have come from chemical preservatives applied by loggers to the wood they sold . As well, the violin makers applied varnishes to their instruments . Potassium borate (borax) may have been used to protect against Woodworm . Sodium and potassium silicate may have been used to prevent mildew, rotting and insect damage . Simone Fernando Sacconi suggested that Vernice bianca, an egg tempera varnish composed of gum arabic, honey, and egg white, may have been used . </P>

What kind of wood is a stradivarius violin made of