IMPROVE- MENTS IN PRODUCING COMPOSITIONS OR COMBINATIONS OF BITUMINOUS, RESINOUS, AND GUMMY MATTERS, AND THEREBY OBTAINING PRODUCTS USEFUL IN THE ARTS AND MANUFACTURES
Year: 1853

page_text: LETTERS PATENT to Admiral the Earl of Dundonald, of Belgrave
Road, in the County of Middlesex, for the Invention of "IMPROVE-
MENTS IN PRODUCING COMPOSITIONS OR COMBINATIONS OF BITUMINOUS,
RESINOUS, AND GUMMY MATTERS, AND THEREBY OBTAINING PRODUCTS
USEFUL IN THE ARTS AND MANUFACTURES."
Sealed the 31st May 1858, and dated the 26th February 1858.
PROVISIONAL SPECIFICATION left by the said Earl of Dundonald
at the Office of the Commissioners of Patents, with his Petition,
on the 26th February 1853.
I, ADMIRAL the EARL OF DUNDONALD, of Belgrave Road, in the
County of Middlesex, do hereby declare the nature of the said Invention
for "IMPROVEMENTS IN PRODUCING COMPOSITIONS OR COMBINATIONS OF BITU-
MINOUS, RESINOUS, AND GUMMY MATTERS, AND THEREBY OBTAINING PRODUCTS
USEFUL IN THE ARTS AND MANUFACTURES," to be as follows:-
My improvements consist in increasing the durability of gutta
percha, caoutchouc, and other gums deposited in humid places, by
means of their admixture or coating with the unctuous oil of petroleum
or tar, well known as a preservative of wood; and also the forming of

page_text: SPECIFICATION in pursuance of the conditions of the Letters Patent,
filed by the said Earl of Dundonald, in the Great Seal Patent
Office, on the 24th August 1853.
.
TO ALL TO WHOM THESE PRESENTS SHALL COME, I,
ADMIRAL the EARL OF DUNDONALD, of Belgrave Road,' in the County of
Middlesex, send greeting.
WHEREAS Her most Excellent Majesty Queen Victoria, by Her
Letters Patent, bearing date the Twenty-sixth day of February, in the
year of our Lord One thousand eight hundred and fifty-three, in the
sixteenth year of Her reign, did, for Herself, Her heirs and successors,
give and grant unto me, the said Earl of Dundonald, Her special
licence that I, the said Earl. of Dundonald, my executors, administra-
tors, and assigns, or such others as I, the said Earl of Dundonald, my
executors, administrators, and assigns, should at any time agree with,
and no others, from time to time and at all times thereafter during the
term therein expressed, should and lawfully might make, use, exercise,
and vend, within the United Kingdom of Great Britain and Ireland, the
Channel Islands, and Isle of Man, an Invention.for "IMPROVEMENTS
IN PRODUCING COMPOSITIONS OR COMBINATIONS OF BITUMINOUS, RESINOUS,
AND GUMMY MATTERS, AND THEREBY OBTAINING PRODUCTS USEFUL IN THE
ARTS AND MANUFACTURES," upon the condition (amongst others) that
I, the said Earl of Dundonald, by an instrument in writing under my
hand and seal, should particularly describe and ascertain the nature of
the said Invention, and in what manner the same was to be performed,
and cause the same to be filed in the Great Scal Patent Office within
six calendar months next and immediately after the date of the said
Letters Patent.
NOW KNOW YE, that I, the said Earl of Dundonald, do hereby
declare the nature of the said Invention, and in what manner the same
is to be performed, to be particularly described and ascertained in and
by the following statement thereof (that is to say):
My improvements in producing combinations of bituminous, resinous,
and gummy matters, and thereby obtaining products useful in the arts

page_text: and manufactures, consist in changing these substances from an indu-
rated and brittle to a plastic, cohesive, flexible, or elastic state; and,-
First, I proceed to describe the means of converting rosin (which I
prefer to be common brown or black rosin) to a consistence per-
manently approaching that of gum caoutchouc. For this purpose I
pound or bruise the rosin, in order to its more speedy and effectual
admixture with a solvent (say of a tenth or twentieth of its weight),
which solvent I prefer to be viscid or unctuous oil of petroleum, or
mineral tar, commonly called dead oil, from its remaining fluid in the
pot or still after the expulsion of the volatile oil (or naptha) and the
inspissation of the pitch.
To this combination, when dissolved (by time or heat), I add one-
fourth, or thereabout, of gum shellac, or gum kanni, or any other
indurated gum, stirring the mixture at a temperature of boiling water
until the whole is thoroughly blended.
If still farther tenacity and flexibility are requisite, I saturate the
viscid oil aforesaid with caoutchouc previous to admixture with the
rosin, shellac, or other gum, which amalgam imparts great additional
cohesion and flexibility, even although the caoutchouc dissolved in the
oil may not exceed one-fortieth of the whole solution.
If a dark colour is not objectionable, pounded bitumen may be
dissolved with the brittle indurated rosin and gum or gums; in this
case mastication is conducive to thorough admixture, especially if a
portion of dry caoutchouc (say one-tenth) is added, to enable the mix-
ture to be used for purposes of a high order, for which gutta percha or
caoutchouc, singly or combined, have hitherto been employed.
In witness whereof, I, the said Earl of Dundonald, have hereunto
set my hand and seal, this Twenty-fourth day of August, in the
vour of our Lord One thousand eight hundred and fife than
DUNDONALD. (L.S.)
Witness, S. CARPMAEL.