Professor Sadler, of the University of Pennsylvania, has lately given
an account of the development and method of the manufacture of
celluloid. Alexander Parkes, an Englishman, invented this remarkable
substance in 1855, but after twelve years quit making it because of
difficulties in manipulation, although he made a fine display at the
Paris Exposition of 1867. Daniel Spill, also of England, began
experiments two years after Parkes, but a patent of his for dissolving
the nitrated wood fiber, or "pyroxyline," in alcohol and camphor was
decided by Judge Blatchford in a suit brought against the Celluloid
Manufacturing Company to be valueless. No further progress was made
until the Hyatt Brothers, of Albany, N.Y., discovered that gum
camphor, when finely divided, mixed with the nitrated fiber and then
heated, is a perfect solvent, giving a homogeneous and plastic mass.
American patents of 1870 and 1874 are substantially identical with
those now in use in England. In France there is only one factory, and
there is none elsewhere on the Continent, one in Hanover having been
given up on account of the explosive nature of the stuff. In this
country pure cellulose is commonly obtained from paper makers, in the
form of tissue paper, in wide rolls; this, after being nitrated by a
bath of mixed nitric and sulphuric acids, is thoroughly washed and
partially dried. Camphor is then added, and the whole is ground
together and thoroughly mixed. At this stage coloring matter may be
put in. A little alcohol increases the plasticity of the mass, which
is then treated for some time to powerful hydraulic pressure. Then
comes breaking up the cakes and feeding the fragments between heated
rolls, by which the amalgamation of the whole is completed. Its
perfect plasticity allows it to be rolled into sheets, drawn into
tubes, or moulded into any desired shape.--_Jewelers' Journal._
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