IMPROVEMENTS IN TREATING AND PURIFYING GUTTA PERCHA
Year: 1859

page_text: LETTERS PATENT to Thomas Cattell, of 30, Euston Square, in the
County of Middlesex, M.D., for the Invention of "IMPROVEMENTS IN
TREATING AND PURIFYING GUTTA PERCHA."
Sealed the 12th August 1859, and dated the 17th February 1859.
PROVISIONAL SPECIFICATION left by the said Thomas Cattell at the
Office of the Commissioners of Patents, with his Petition; on the 17th
February 1859.
I, THOMAS CATTELL, of 30, Euston Square, in the County of Middlesex,
M.D., do hereby declare the nature of the Invention for "IMPROVEMENTS
IN TREATING AND PURIFYING. GUTTA, PERCHA," to.be as follows:-
This Invention consists in treating gutta percha by the operation follow-
ing, that is to say:-For perspicuity of description and reference the said
operation is distinguished,―
as
1st, by the stage involving the dissolution of the gutta percha. The
gutta percha to be operated upon is preferred to be cleansed
much as
possible, by kneading it or otherwise macerating and working it under
water, comminuted or divided into shreds and dried. "It is then exposed to
the action of two classes of volatile solvents; 1. That class whose solventicity
bears a ratio and relation to elevation of temperature, coal tar naptha, and
its rectified products, also other hydrocarbons, turpentine, and resin spirit ;
2. The class which determines its solubility in the cold, technically so termed;
bisulphuret of carbon and chloroform. As it is an object on my part to
extract the gutta percha as free, as possible from, the colouring as well as the
Price 8d1

page_text: feculent and insoluble matters, with which it is always more or less com-
bined, I treat either class of solvents specified; 1st, while in their free
condition, on the principle that the simultaneous solution of the colouring
matters may be prevented or modified without diminishing in any appreciable
degree the solventicity of the said agents in relation to the gutta percha.
With this view, therefore, I add a small quantity of spirit of nitric ether,
pyroxylic spirit, alcohol holding in solution a little anhydrous glycerine,
soap, and other chemical agents. 2ndly, when holding gutta percha in
solution, on the principle that the colouring matters may be set free or
destroyed without disturbing the solubility of the said substance.
In either case I employ the previously mentioned agents, or add a little
solution of chloride of calcium, bichromate of potash, sulphuric or hydro-
chloric acid, and other chemical agents, or I filter the said solutions through
moulded carbon, granulated or in any suitable form.
II. By the stage involving the reduction or revival of the gutta percha
from the state of solution effected, and treated in the manner described.
I shall here also further distinguish this stage of the operation by a
description of the three distinct processes to which I have recourse in
effecting the recovery of the gutta percha.
1. THE PROCESS OF CONGELATION.
In carrying out this process, I take a thick solution of gutta percha
prepared by the first class of solvents (preferring benzole) described under
the first stage of the operation, and expose it to a temperature of 32° of
Fahrenheit's thermometer (or a lower temperature) so that congelation,
that is to say, a solidified state of the gutta percha solution, may take place.
I now take this congelated or solidified mass, and complete the process in
the following manner:-1st, I submit the said mass to suitable pressure;
2nd, I submit the said mass to centrifugal force; 3rd, I heat the mass in
a way technically termed "filtration in vacuo."
In preparing a granulated form of gutta percha, I take the mass thus
heated, and while exposed to a warm atmosphere, occasionally stir it until
complete dessication is established.
2. THE PROCESS OF DISTILLATION.
In this process I take solutions of gutta percha prepared by either class
of volatile solvents described under the 1st stage of this operation, and
effect a separation of the solvent and gutta percha by submitting them to
distillation in direct contact with water or free steam.

page_text: 3. THE PROCESS OF PRECIPITATION.
In this process I take solutions of gutta percha prepared by the 1st class of
solvents described under the first stage of the operation, and add thereto a
suitable precipitating agent, such as pyroxylic spirit, fusel oil, or alcohol in
about equal measures, the result being an immediate separation of the gutta
percha, which agglutinates and subsides in the vessel, leaving a limpid fluid,
consisting (only) of the solvent and precipitent.
SPECIFICATION in pursuance of the conditions of the Letters Patent, filed
by the said Thomas Cattell in the Great Seal Patent Office on the
17th August 1859.
TO ALL TO WHOM THESE PRESENTS SHALL COME, I, THOMAS
CATTELL, of 30), Euston Square, in the County of Middlesex, M.1)., send
greeting.
WHEREAS Her most Excellent Majesty Queen Victoria, by Her Letters
Patent, bearing date the Seventeenth day of February, in the year of our
Lord One thousand eight hundred and fifty-nine, in the twenty-second year
of Her reign, did, for Herself, Her heirs and successors, give and grant
unto me, the said Thomas Cattell, Her special licence that I, the said Thomas
Cattell, my executors, administrators, and assigns, or such others as I, the
said Thomas Cattell, 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 Ire-
land, the Channel Islands, and the Isle of Man, an Invention for "IMPROVE-
MENTS IN TREATING AND PURIFYING GUTTA PERCHA," upon the condition (amongst
others) that I, the said Thomas Cattell, my executors or administrators, by an
instrument in writing under my, or their, or one of their hands and seals,
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 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 Thomas Cattell, 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 :-

page_text: This Invention has for its object improvements in treating and purifying
gutta percha (that is to say.):-
For perspicuity of description and reference, the said operation is dis-
,tinguisheḍ,-
First, by the stage involving the.dissolution of the gutta percha. The
gutta percha to be operated upon is preferred to be cleansed by well-known
mechanical processes, at the same time it, is not essential for the purpose of
this operation. The gutta percha is then exposed to the action of volatile
solvents of two classes, in the proportion of one part by weight to about 15
parts of solvent.
1. That class whose solventicity bears a ratio and relation to elevation of
temperature, coal tar naptha, and its rectified products; also other hydro-
-carbons, turpentine, and resin spirit.
2. The class which determines its solubility in the cold, technically so
termed, bisulphuret of carbon and chloroform.
As it is an object on my part, to extract the gutta percha.as free as possible
from the coloring as well as the feculent and insoluble matters, with which it
is always,more or less-combined, I treat either class of solvents specified,
First, while in their free. condition, on the principle that the simultaneous
solution of the colouring matters.may be prevented or modified, without
diminishing in any appreciable degree the solventicity of the said agents in
relation to the gutta percha.
Secondly, when holding gutta percha in solution, on the principle that the
coloring matters may be set free without disturbing the solubility of the said
substance.
In conducting this stage of the operation by the first class of solvents
specified, I add at the same time the gutta percha and the solvent are
brought in contact, one ounce of alcohol, holding thirty drops of glycerine
in solution to each gallon; or one ounce of alcohol, holding thirty grains of
soap in solution; or one ounce of pyroxilic spirit, holding thirty drops of
glycerine in solution; or one ounce of commercial nitrate of the oxide of
ethyl in the same proportion.
I use a close vessel fitted with an agitator, heated by hot water or steam to
a temperature of about 110° Fahrenheit, and kept in motion for about an
hour, or until the gutta percha is dissolved. I allow the whole to stand for
twenty-four hours, when if not sufficiently defecated and decolorized, I decant
off the greater bulk of the gutta percha solution into another vessel, and
further add, accompanied by agitation, either of the solutions, preferring the
first solution already mixed with the solvent.

page_text: In conducting this stage of the operation by the solvents of the second class,
that is to say, by means of bisulphuret of carbon, no heat is applied.
Second, by the stage involving the reduction or revival of the gutta percha
from the state of solution, effected and treated in the manner described.
I shall here also further distinguish this stage of the operationby a descrip-
tion of the three distinct processes, preferring the process of distillation and
the process of precipitation to which I have recourse in effecting the recovery
of the mitte nescho
In this process I take solutions of gutta percha prepared by the first class of
solvents described under the first stage of the operation, preferring benzole
solution, and mix therewith or add thereto about au equal measure of

page_text: alcohol, methylated or not, and preferred to be about 65° over proof, or
pyroxylic spirit (preferable anhydrous), of fusel oil.
The mixed fluid is then stirred for a few seconds, allowed to stand for a
short time, then drawn' off, leaving the gutta pérohä ready for use.
In witness whereof, I, the said Thomas Cattell, have hereunto set my
hand and seal, this Seventeenth day of August, in the year of our Lord
One thousand eight hundred and fifty-nine.