ining and purifying
Year: 1897

page_text: I, WILLIAM RAMSAY, of the University College, Gower Street, in the County of
London, Professor of Chemistry, do hereby declare the nature of this invention
to be as follows:-
This invention relates to improvements in obtaining and purifying gutta-percha
and has reference more particularly to the extraction of gutta-percha from the
leaves and twigs of the "Isonandra Gutta-percha" or from other trees or plants
containing the gums which constitute gutta-percha.
The invention further has reference to the purification of the ordinary gutta-
percha of commerce.
The essential feature of the invention consists in the substitution of rosin oil for
the volatile solvents, such as that known as toluol or toluene, which are sometimes
employed in the extraction and purification of gutta-percha, for the purpose of
dissolving the latter, for example in the process described by Eugene Serullas and
Felix Hourant in the Specification of British Letters Patent granted to them
No. 654 dated the 9th January 1896.
According to my said invention, for the purpose of extracting gutta-percha
from leaves or twigs containing the same, such leaves or twigs are first treated
with or macerated in hot or cold water and are then subjected to the action of an
alkaline solution, which is afterwards removed by washing the leaves or twigs
with water.
I then treat the said leaves or twigs with rosin oil, which dissolves out the
various gutta-percha gums contained in them. These gums are afterwards pre-
cipitated by acetone or other suitable reagent the precipitate is then separated
from the liquors preferably by the use of a filter press and it then constitutes the
gutta-percha which it is the object of this part of the invention to extract.
For the purpose of purifying gutta-percha, such as crude commercial gutta-
percha, from woody fibre or from other impurities which it may contain I dissolve
the same in rosin oil and I then precipitate the gutta-percha by means of acetone
or other suitable reagent.
After the precipitation of the gutta-percha either in the extracting or the
purifying process, the acetone may be separated and recovered from the rosin oil
by distillation.
By the employment of the solvent above referred to, that is to say rosin-oil, I
am enabled to effect the solution of the gutta-percha gums without the expense and

page_text: danger that are incurred by the employment of a highly volatile solvent such as
toluol or toluene.
Doted this 20th day of July 1897
HASELTINE, LAKE & Co.,
45 Southampton Buildings, London, W.C., Agents for the Applicant.
Improvements in Extracting and Purifying Gutta-percha.
I, WILLIAM RAMSAY, of the University College, Gower Street, in the County of
London, Professor of Chemistry, do hereby declare the nature of this invention
and in what manner the same is to be performed, to be particularly described and
ascertained in and by the following statement:-
This invention relates to improvements in obtaining and purifying gutta-percha
and has reference more particularly to the extraction of gutta-percha from the
leaves and twigs of the "Isonandra Gutta-percha or from other trees or plants
containing the gums which constitute gutta-percha.
"
The invention further has reference to the purification of the ordinary gutta-
percha of commerce.
The essential feature of the invention consists in the substitution of rosin oil for
the volatile solvents, such as that known as toluol or toluene, which are sometimes
employed in the extraction and purification of gutta-percha, for the purpose of
dissolving the latter, for example in the process described by Eugene Serullas and
Felix Hourant in the Specification of British Letters Patent granted to them
No. 654 dated the 9th of January 1896.
According to my said invention, for the purpose of extracting gutta-percha
from leaves or twigs containing the same, such leaves or twigs are first treated
or macerated in hot or cold water and are then subjected to the action of an
alkaline solution, which is afterwards removed by washing the leaves or twigs with
water. I then treat the said leaves or twigs with rosin oil, at a temperature of 80°
to 120° or 130° C. in a closed vessel which dissolves out the various gutta-percha
gums contained in them. These gums are afterwards precipitated by a sufficient
quantity of acetone or other suitable reagent. The precipitate is separated by use
of a filter press and it then constitutes the gutta-percha which it is the object of
this part of the invention to extract.
For the purpose of purifying gutta-percha, such as crude commercial gutta-
percha, from woody fibre or from other impurities which it may contain I dissolve
the same in rosin oil and I then precipitate the gutta-percha by means of acetone
or other suitable reagent.
After the precipitation of the gutta-percha either in the extracting or the
purifying process, the acetone may be separated and recovered from the rosin-oil
by distillation.
By the employment of the solvent above referred to, that is to say rosin-oil, I
am enabled to effect the solution of the gutta-percha gums without the expense and
danger that are incurred by the employment of a highly volatile solvent such as
toluol or toluene.
Having now particularly described and ascertained the nature of my said
invention and in what manner the same is to be performed, I declare that what
I claim is:-
1. The employment of rosin oil as a solvent for gutta percha in the extraction
or purification of the latter.

page_text: 2. The extraction of gutta percha from the leaves or twigs of plants containing
the same, by means of rosin oil.
3. My improvements in extracting and purifying gutta percha, substantially
as hereinbefore described.
Dates: 20th day of Tu1 1007
HASELTINE, LAKE & Co.,
45 Southampton Buildings, London, W.C., Agents for the Applicant.