AN IMPROVED METHOD OF TREATING OR PURIFYING GUTTA PERCHA
Year: 1857

page_text: LETTERS PATENT to Horace Hollister Day, of New York, in the United
States of America, India-rubber Manufacturer and Merchant, for the
Invention of "AN IMPROVED METHOD OF TREATING OR PURIFYING GUTTA
PERCHA."-A communication.
Sealed the 18th December 1857, and dated the 19th June 1857.
PROVISIONAL SPECIFICATION left by the said Horace Hollister Day
at the Office of the Commissioners of Patents, with his Petition, on
the 19th June 1857.
I, HORACE HOLLISTER DAY, of New York, in the United States of America,
India-rubber Manufacturer and Merchant, do hereby declare the nature of
the said Invention for "AN IMPROVED METHOD OF TREATING OR PURIFYING
GUTTA PERCHA," to be as follows:--
In the treatment of gutta percha preparatory to being fitted for the process
of vulcanization, there has been found a great difficulty hitherto in extracting
from it its peculiar etheric oil. This has chiefly been effected by pre-heating
the gutta percha, either alone or in combination with other matters, and thus
driving off the said oil by vaporization. The subsequent working of the gutta
percha is thus rendered more difficult, for the reason that the woody matter
and other foreign substances are held far more closely after having been once
heated than before. From this difficulty it has heretofore occurred that
although this gum is chemically almost identical with india-rubber, and is

page_text: applicable to similar purposes, still, from the difficulty of preparing it as
compared with caoutchouc, a preference is given to the latter in many manu-
factures.
The present improvement in purifying the gutta percha consists in sub-
mitting it to the action of a liquor which dissolves out the etheric oil, and also
at the same time by acting upon the woody matter disengages the sand held
with that.
To effect this object, one pound of caustic potash (hydrate of potassa) is
dissolved in two gallons of water, and to this is added an ether formed from a
solution of chloride of lime in alcohol. Into this mixture the crude gutta
percha which had previously been finely cut is placed, and the whole is then
to be heated' to the boiling point, and so kept for from eight to ten hours, after
which the gutta percha is removed from the liquor and treated between rollers
under water in a purifying machine, in the ordinary manner. When taken
out the gum will be a pure and solid mass, resembling india-rubber very
much, and fully equal to it in fineness and in the readiness with which it
may be worked. As thus treated the gutta percha may now be perfectly
vulcanized in the usual manner with sulphur, at a single heating.
The liquor may be used for several parcels of gutta percha by merely adding
for each a fresh supply of the ether, as the alkaline quality diminishes but
little.
SPECIFICATION in pursuance of the conditions of the Letters Patent, filed
by the said Horace Hollister Day in the Great Seal Patent Office on
the 18th December 1857.
TO ALL TO WHOM THESE PRESENTS SHALL COME, I, HORACE
HOLLISTER DAY, of New York, in the United States of America, India-
rubber Manufacturer and Merchant, send greeting.
WHEREAS Her most Excellent Majesty Queen Victoria, by Her Letters
Patent, bearing date the Nineteenth day of June, in the year of our Lord
One thousand eight hundred and fifty-seven, in the twentieth year of Her
reign, did, for Herself, Her heirs and successors, give and grant unto me, the.
said Horace Hollister Day, Her special license, that I, the said Horace
Hollister Day, my executors, administrators, and assigns, or such others as
I, the said Horace Hollister Day, 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

page_text: make, use, exercise, and vend, within the United Kingdom of Great Britain
and Ireland, the Channel Islands, and Isle of Man, an Invention for "AN
IMPROVED METHOD OF TREATING OR PURIFYING GUTTA PERCHA," being a com-
munication from abroad, upon the condition (amongst others) that I, the said
Horace Hollister Day, by an instrument in writing under my hand and
seal, should particularly describe and ascertain the nature of the said Inven-
tion, and in what manner the same was to be performed, and cause the
same to be filed in the Great Seal Patent Office within six calendar months
next and immediately after the date of the said Letters Patent. .
NOW KNOW YE, that I, the said Horace Hollister Day, 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 (that is to say) :-
the
In the treatment of gutta percha, preparatory to its being submitted to
process of vulcanization, there has been found a great difficulty hitherto
in extracting from it a peculiar etheric oil which it contains. This object has
usually been effected to some extent by pre-heating the gutta percha, either
alone or in combination with other matters, and thus driving off a considerable
portion, if not all, of the said oil by vaporization. The subsequent working
of the gutta percha is by this operation rendered more difficult, because the
woody matter and other foreign substances mixed with the gum are held far
more closely, or with greater tenacity, after the substance has been once heated
than before. From this difficulty it has heretofore occurred, that although
this gum is chemically almost identical with india-rubber, and is applicable to
many similar purposes in the arts, still, from the difficulty of properly pre-
paring it (as compared with caoutchouc), a preference is given to the latter in
many manufactures.
The present.improvement in purifying the gutta percha consists in sub-
mitting it to the action of a liquor which dissolves out the etheric oil, and also
at the same time, by acting upon the woody matter, disengages the sand and
other foreign matters held therewith.
To effect this object one pound of caustic potash (hydrate of potassa) is
dissolved in two gallons of water, and to this is added an ether formed from
a solution of chloride of lime in alcohol. The most convenient proportions
for these materials I have found to be about four ounces of chloride of lime
in eight ounces of alcohol, marking eighty degrees on the hydrometer, but I
do not confine myself to these proportions. Into this mixture about fifteen
pounds of crude gutta percha, which had previously been finely cut, is placed.
The whole mass is then to be heated to the boiling point, and so kept for from

page_text: eight to ten hours, after which the gutta percha is removed from the liquor
and treated between rollers under water in a purifying machine in the ordinary
manner.
When taken out, the gum will be found to consist of a pure and solid mass,
resembling india-rubber very much, and fully equal to it in fineness and in the
readiness with which it may be worked. After having been treated in this
manner, the gutta percha may be perfectly vulcanized in the usual way,
with sulphur, at a single heating of from four to seven hours, and at a tem-
perature of from two hundred and thirty to two hundred and ninety degrees
of Fahrenheit..
The liquor may be used for several parcels of gutta percha by merely adding
for each lot a fresh supply of the ether alone, as the alkaline quality diminishes
but little.
Having now described the Invention of "An Improved Method of Treating
or Purifying Gutta Percha that has been communicated to me by my foreign
correspondent, and having explained the manner of carrying the same into
effect, I would observe in conclusion that the Invention. or discovery which I
consider to be new, and therefore desire to claim and secure by Letters
Patent, as aforesaid, is the mode herein described and set forth of treating
or purifying gutta percha, or any mere modification thereof, whereby the
objected is effected by means of the ether or alkali, above mentioned, or
their equivalents, used in the manner herein set forth.
In witness whereof, I, the said Horace Hollister Day, have hereunto"
set my hand and seal, the Second day of November, in the year of
our Lord One thousand eight hundred and fifty-seven.
HORACE H. DAY. (L.S.)