daguerreotype
noun /dəˈɡerətaɪp/
  /dəˈɡerətaɪp/
(also daguerrotype)
 - a photograph taken using an early process that used a silver plate and mercury gasWord Originmid 19th cent.: from French daguerréotype, named after L.-J.-M. Daguerre (1789-1851), the French physicist, painter and inventor of the first practical photographic process.