AN IMPROVED MODE OF TREATING INDIA- RUBBER, GUTTA PERCHA, AND ANALOGOUS GUMS
Year: 1859

page_text: PROVISIONAL SPECIFICATION left by Alfred Vincent Newton at the
Office of the Commissioners of Patents, with his Petition, on the 2nd
December 1859.-A communication from abroad by George August
Engelhard and Horace Hollister Day, of New York, in the United
States of America.
I, ALFRED VINCENT NEWTON, of the Office for Patents, 66, Chancery Lane,
in the County of Middlesex, Mechanical Draughtsman, do hereby declare the
nature of the said Invention for "AN IMPROVED MODE OF TREATING INDIA-
RUBBER, GUTTA PERCHA, AND ANALOGOUS GUMS," to be as follows:-
It has been generally supposed that the only action which chlorine has
upon india-rubber, gutta percha, and the allied or analogous gums, is a
bleaching action, and that if the said gums are in a solid state, the effect of
the chlorine on them is so slow that it takes a long time to produce a
perceptible change; solid lumps of gutta percha, india-rubber, or the allied
gums may, however, be brought under the influence of chlorine by enclosing
the same in an air-tight vessel, and introducing thereto a stream of chlorine.
The gum thus treated begins to swell and becomes converted into a white
brittle mass, When well washed in water to clear it from the adherent
chlorine, the mass is dissolved in one of the well-known solvents of these gums,
such as bisulphuret of carbon, chloroform, benzole, or naphtha, or other
essential oil, and from this solution the new product is precipitated by

page_text: evaporating in an open vessel of more or less thickness, and in this manner it
may be applied to the articles to which it is designed to be attached by
moulding, dipping, and by other modes. A more rapid way of producing this
change is to dissolve the gum in one of the well-known solvents, such as bi-
sulphuret of carbon, benzole, chloroform, or naphtha, and to bring the solution
into contact with a stream of gaseous chlorine. The solution, which is of a
dark color when first prepared, turns lighter and lighter as the effect of the
chlorine is continued, and after a time it becomes yellow. At this period of
the operation the material is flexible and limp, like leather; if, however, it is
required to be made hard, like what is known in commerce as "vulcanite,"
the action of the chlorine is continued until such effect is produced, which will
be well understood by workmen accustomed to work it. The solvent is
removed by evaporation, or it may be done by treating the mixture with
alcohol, which combines with the solvent, and causes the gum combined
with the chlorine to precipitate. By adding water. to the alcohol, the
solvent may be separated from the same, so that it can be used over and
over again. After removing the liquid by filtering or evaporation of the gum
and chlorine, it is well washed with alcohol, and then pressed and dried, when
it forms a white and hard mass.
This composition of the above-mentioned gums is soluble in all the usual
solvents of the said gums; but water or acids have no influence on the same,
and on account of its white color, and also by reason of its hardness, it can be
applied to a great variety of uses in the arts.
A part of this Invention relates to a new mode of dissolving india-rubber,
gutta percha, or other allied gums, applicable to the manufacture of the new
product in combination with the foregoing, and also to other purposes.
The india-rubber, gutta percha, or other gums, having been cleaned and cut
into small pieces, is to be placed in chloride of carbon contained in a suitable
vessel of glass or metal. The perfect solution takes place in the space of from
one to two days, and may be facilitated by warming.