IMPROVEMENTS IN THE MANUFACTURE OF CANDLES AND OPERATING UPON OILS AND FATS
Year: 1840

page_text: TO ALL TO WHOM THESE PRESENTS SHALL COME, I, GEORGE
GWYNNE, of 3, Portland Terrace, Regent's Park, in the County of Middlesex,
Gentleman, send greeting.
Her
WHEREAS Her present most Excellent Majesty Queen Victoria,
Letters Patent under the Great Seal of Great Britain, beåring date at
Westminster, the Tenth day of March, in the third year of Her reign, did,
for Herself, Her heirs and successors, give and grant unto me, the said George
Gwynne, Her especial licence, full power, sole privilege and authority, that I,
the said George Gwynne, my exors, adññors, and assigns, or such others as I,
the said George Gwynne, my exors, admors, or assigns, should at any time.
agree with, and no others, from time to time and at all times during the term
of years therein expressed, should and lawfully might make, use, exercise,
and vend, within England, Wales, and the Town of Berwick-upon-Tweed, my
Invention of "IMPROVEMENTS IN THE MANUFACTURE OF CANDLES AND OPERATING
UPON OILS AND FATS;" in which said Letters Patent is contained a proviso that
I, the said George Gwynne, shall cause a particular description of the nature
my said Invention, and in what manner the same is to be performed, to
be inrolled in Her said Majesty's High Court of Chancery within six
calendar months next and immediately after the date of the said in part
recited Letters Patent, as in and by the same, reference being thereunto had,
will more fully and at large appear.
of
NOW KNOW YE, that in compliance with the said proviso, I, the said
George Gwynne, do hereby declare the nature of my said Invention, and the

page_text: manner in which the same is to be performed, are fully described and
ascertained in and by the following statement thereof, reference being had
to the Drawings hereunto annexed, and to the figures and letters marked
thereon, that is to say:-
The first part of my Invention relates to a mode or modes of treating fats
and oils by carbonated alkalies, whereby common candles of a better quality
than are now made from tallow, mutton fat, &c. can be manufactured, and
oils better fitted for all the purposes to which they can be applied.
Secondly, my Invention relates to a mode or modes of treating by distilla-
tion in vacuo fatty and oily matters and their products, in order to the
production of materials better suitable for the manufacture of candles, and
the other various purposes for which such bodies are applicable.
Thirdly, my Invention relates to a mode or modes of treating by distillation,
and where necessary by repeated distillations, under atmospheric pressure,
certain bodies obtainable from fats and oils, whereby beneficial results can be
obtained; and,
Fourthly, my Invention relates to a mode or modes of separating the
fluid from the solid parts of fats and oils by taking advantage of the
different degrees of solubility which such matters offer when converted into
salts.
Having thus stated the objects of my Invention, I will proceed to describe
the processes pursued by me in carrying out my Invention in treating the
fats and oils with carbonated alkalies. Into a vessel of a suitable size I
put, say, two hundred and twenty imperial gallons of cold water and two
hundred and eighty pounds of carbonate of potassa (potash); carbonate of
soda may be substituted for potassa, but in this case I employ five hundred
and sixty pounds. I now turn on the steam, which is applied by a perforated
pipe, and bring the solution to the boiling point, when I add twenty cwt
of tallow or other fat, and continue the ebullition for eight hours; and
it should be remarked, that when the mixture comes to the boiling point,
a very considerable frothy head is formed. In such case the steam should
be checked to prevent boiling over, and in a few minutes the froth goes down,
and ebullition proceeds steadily. After boiling eight hours I shut off the
steam, and allow the mixture to repose until next day. At this time the
greater part of the water and carb. potassa will have settled into the lower
part of the vessel, from which they are drawn off by a cock at the bottom.
For distinction's sake I call this solution "lye." A small quantity of oily
matter will be found dissolved in it, which I extract by a method which I
shall describe presently, as also the mode I adopt for using the "lye" over

page_text: again. After the "lye" is drawn off as above described, I transfer the
tallow, which has a soapy appearance, into an iron or other suitable vessel
heated by a "steam jacket" in a manner perfectly well known. To the
tallow I now add two hundred and eighty pounds of carb. potassa, and raise
the temperature to one hundred and ten degrees of Fahrenheit. I incorpo-
rate the tallow and carb. potassa thoroughly by stirring. The stirring may
be performed either by hand or machinery, but perfect incorporation is
necessary for the success of the process. I now raise the temperature to
two hundred degrees of Fahrenheit, when the steam is shut off and the
mixture is allowed to repose for about twelve hours; a small portion of scum
rises to the surface, which I remove with a perforated ladle. After having
stood about twelve hours, I draw off the tallow (which has now lost completely
its soapy appearance) into tinned pans or other vessels, and allow it to get
solid. The refining of the tallow is now completed, with the following
exception. It does not settle perfectly bright in the vessel with the "steam
jacket," and it requires to be again melted in another vessel with a steam
jacket," the temperature raised to two hundred degrees Fahrenheit; it is
then to be allowed to stand for a few hours, when it will be found perfectly
transparent and better fitted for making candles than tallow as ordinarily
prepared.
The following is the method I pursue with oils, such as rape or whale
oil, which are liquid at the ordinary temperature of the atmosphere :-
I boil the oil with water and carb. potassa precisely in the same
manner as tallow. After the "lye" is drawn off I transfer the oil,
which has the appearance of soft soap, into another vessel, where I allow it
to stand for eight days. At the end of this time some more "lye" will
have settled out of the oil. This "lye" is to be drawn off, and the
oil transferred into a vessel with a "steam jacket," and have stirred into it
the same quantity of carb. potassa as in the case of the tallow, and the tem-
After standing a
perature raised to about two hundred degrees Fahrenheit.
day, the oil is to be drawn off.
appearance, but it is still slightly turbid.
either by filtration or repose before it is fit for use; prefer allowing it to
settle bright. It takes from a month to five weeks to accomplish this. I stir
the second quantity of carb. potassa into oils and fats in the vessel with the
steam jacket for the purpose of carrying down the impurities. It performs
the same function as "finings" do in rendering fermented liquors transparent..
The active properties of the carb. of potassa are not injured by the operation,
I therefore use such carbonate of potassa again instead of fresh carbonate of
It will be found to have lost its soapy
This turbidity should be removed

page_text: potassa in treating the next quantity of raw fat or oil I operate on. 'The
mode of operating on the "lye" which I prefer to use is as follows:-I bring
the "lye" to the boiling point, and carefully add thin cream of lime until the
whole of the oily matter is removed. This is easily ascertained by adding a
few drops of diluted acid of any kind to a little of the lye; if any oily matter
is present, the acid causes a milky appearance in the lye.
the oily matter by lime, I evaporate the lye to dryness, and ignite it along
with a little sawdust, as is well understood. The carb. of potassa can now be
obtained by washing fit for using again. To the lime and oily matter I add
diluted sulphuric acid in the manner of the "stearine wax" manufacturer.
Having removed
I am aware that caustic or partially caustic alkalies have been used, or
have been attempted to be used, in purification of oleaginous bodies, I do not
therefore claim the same; and I would remark that they form a true soap
with almost all fats and oils, whereas the carbonated alkalies do not produce
saponification of natural fats and oils, and it will be found that the soapy
appearance fats and oils assume when boiled with carbonated alkalies is
deceptive, being only a mixture formed by the "lye" and the impurities of
fats and oils. Before I conclude the description of this part of my Invention
for the refining of fats and oils in their natural state, I may remark that
many of them contain a minute quantity of volatile oil of a very pungent and
disagreeable nature, which can be driven off by heat. Frequently this volatile
oil is highly coloured, and its removal, independent of being agreeable to
the smell, improves the color of the oil very much. As an instance, rape oil,
after being refined by carb. potassa, is as dark colored and smells quite as
disagreeable as in its original state. After refining I put it into an iron
vessel to the depth of six or eight inches, and raise the temperature as
rapidly as possible to about four hundred and ninety degrees Fahrenheit. I
take care never to exceed five hundred degrees. When cold the oil will be
found exceedingly pale in the color, and to have lost its disagreeable smell.
In order that the second and third parts of my Invention may be clearly
perceived, I may remark that it is known to persons acquainted with organic
chemistry that fatty acids, such as the stearic, margaric (generally known in
commerce by the name of "stearine wax"), oleic (commonly called "tallow oil")
acids really exist as acids in fats and oils, having their acid properties
neutralized by the glycerine in the same manner as soda neutralizes sulphuric
acid. It is also known that there are several modes of obtaining the fatty
acids. It is further known that the fatty acids are much more inflammable
than natural oils and fats, that they are acid to test paper, that they decompose
carbonate of soda, carbonate of potassa, &c., and are not capable of being used

page_text: for machinery purposes from their acid nature.
Part of the objects of my
Invention is to obtain fatty acids in a much higher degree of purity than they
have been obtained before on a large scale, and further to obtain from fatty
and oily matters fatty bodies which are not acid to test paper, and which will
not act injuriously on machinery.
I will now proceed to describe the second part of my Invention. I obtain
the fatty acids either by the mode generally practised at present, or by any
other suitable means, and separate them into solid and liquid matters, either
by hydraulic pressure, as generally practised (hot pressing being omitted), or by
any other suitable means. I then put the solid matter (stearine wax) into a
vacuum pan, very similar to that now employed by the sugar refiners. I prefer
to substitute a coke fire instead of steam heat, and to raise or lower the fire
by means of a rack and pinion, as shewn in the Drawing, or by any other
suitable means, in order to afford the power of regulating the temperature of the
contents of the vacuum pan at will. During the operation the thermometer
should be frequently examined, and as the "stearine wax" evaporates away fresh
material should be added through the supply pipe b. The distilled product
thus obtained will be better applicable to the manufacture of candles, and is
to be used in like manner to the same materials when not subjected to dis-
tillation in vacuo. The solid matter (tallow oil), obtained as above described,
or by any other convenient method, I also submit to distillation in a vacuum
pan as above described. The distilled oleic acid on cooling will have in it a
considerable quantity of solid fatty acids, which are to be separated by means
of the filtering apparatus to be described hereafter, or by any other suitable
means. This filtered oleic acid I sometimes subject to a second distillation
along with lime, the quantity of which varies from one to six pounds for each
cwt. of the oleic acid; this variation depends on the state into which I wish to
convert the oleic acid. Six pounds per cwt. I find sufficient to change the oleic
acid completely, so that it neither turns test paper nor decomposes carbonate
of soda; I seldom, however, exceed two pounds per cwt., as I find that sufficient
for practical purposes. The following is the mode observed in treating the
distilled oleic acid with lime :-Into a vessel of a suitable size, and heated by
means of a perforated steam pipe, I put two hundred and twenty imperial
gallons of cold water, and twenty cwt. of oleic acid;. I turn on the steam and
bring them to the boiling point, when I add thin cream of lime in the proportions
before stated, and continue the ebullition for thirty minutes. The mixture I
allow to repose until next day, when the oleic acid and lime will have floated
to the top, which I transfer into the vacuum pan, and again submit to distil-
lation. I reserve about the first three fourths of the product for use, and the

page_text: other fourth I again distill with fresh materials. I would remark that it is
not absolutely necessary to saponify fats and oils before distilling them in
vacuo, as distilling them in vacuo, without undergoing previous saponification
will be found advantageous, nor is lime absolutely necessary in distilling the
oleic acid a second time in vacuo, although I prefer to use it.
The third part of my Invention consists chiefly of a mode or modes of
distilling, and sometimes when necessary repeatedly distilling, under atmo-
spheric pressure the fatty acids (no matter how or by what means obtained),
whereby I am enabled the better to get rid of impurities contained therein
than by processes at present practised.
I now proceed to state three modes of obtaining the fatty acids (to none of
which do I make any claim), as also the plan of distilling under atmospheric
pressure, which I find useful. The fatty acids are to be procured in the
manner now practised by the "stearine wax" manufacturer, and they are to be
separated into "stearine wax" and tallow oil in the manner now employed;
"hot pressing," however, is not requisite. The "stearine wax" is put into an
iron still or retort, to which a pipe with a jet of cold water is attached in the
manner stated in the description hereafter given of the vacuum pan. This
pipe and jet of water is intended to supply the place of a worm or refrige-
rator. It will be advisable to have a thermometer inserted into the still or
retort in order to examine the temperature, which should be kept as low as
possible. I find that the "stearine wax" begins to rise in vapour at the
temperature of about three hundred and fifty degrees, and it boils quite violent
at five hundred degrees of Fah. This latter temperature should not be
exceeded as long as the "stearine wax " rises in vapour; a higher heat will be
required to drive over the last portions. I find it desirable that only about
the first three fourths of the "stearine wax" should be reserved for use and
the other fourth kept separate and again distilled along with fresh material.
The product thus obtained will be found beautifully white, but it has an
offensive smell, owing to the presence of a volatile oil, which can be driven off
by being boiled for a considerable time with water and steam, or by being
kept at the heat of about one hundred and fifty degrees of Faht for some days.
The olele acid (tallow oil) separated from the stearine wax as above described,
I also submit to distillation in a similar still or retort. I observe the same
care as to temperature as in the stearine wax distillation, but I do not separate
it into two products, but distill it a second time with lime, precisely in the
manner as before described for distilling tallow oil in vacuo. The distilled
oleic acid has an offensive smell similar to the distilled "stearine wax," which
is to be got rid of in the manner before described.

page_text: Another method is to take tallow or any other fat or oil, and treat it with
about one-fifth of its weight of concentrated sulphuric acid ("oil of vitriol ").
If it be a fat such as tallow which is to be operated on, it must be melted,
and, when the temperature bas sunk to about one hundred and five degrees
Fahrenheit, the sulphuric acid is to be very slowly added (if it be an oil as
whale oil, no heat need be applied), constant agitation being kept up. In
fact no matter what fat or oil is operated on, the acid must be added very
slowly, as otherwise it will heat so rapidly as to destroy the fat or oil. An
hour should be consumed in adding the acid, and the agitation kept up for
half an hour afterwards. At the end of this time a quantity of water, about
equal in bulk to the fat or oil heated to about one hundred and twenty degrees
of Fah, if for tallow (for oils liquid at the ordinary temperature of the atmo-
sphere cold water will do) is to be added and well mixed by stirring, and the
whole allowed to repose until next day. The fatty or oily matter is now to be
removed into a vessel heated by a perforated steam pipe, where it is to be
repeatedly boiled in a quantity of water in order to remove the sulphuric acid.
For such boiling I use about the same bulk of water as there is fatty or oily
matter. The solid and liquid fatty matters (if tallow) are to be separated by
pressure, as in the manufacture of "stearine wax, (if oil by the filtering appa-
ratus hereafter described, or by other suitable means, and the products are
then to be distilled and treated as in the manner before described for "stearine
wax" and "tallow oil" distilled under atmospheric pressure. I may here
remark that oils and fats treated by concentrated sulphuric acid are very trou-
blesome to distil, as they rise in a very frothy state in the retort. I find that
lime is the best agent for keeping down the frothy head.
A third mode is to distil fats or oils as they are found in their natural state,
to wash the distilled products by water and steam, to separate the liquid and
solid fatty acids by pressure, as in the manufacture of stearine wax, or by other
suitable means, and then treat the products by distillation and also get rid of the
offensive smell as before described for "stearine wax," and tallow oil distilled
under atmospheric pressure. The remainder of the third part of my Invention
consists as follows:-I saponify fats or oils with lime, potassa, soda, or bodies
of like nature in the manner well understood, and I distil the soaps formed
as above described in a retort or other suitable vessel under atmospheric
pressure, and by so doing obtain fatty or oily bodies as the case may be. To
no part of the last-described operations for obtaining the fatty or oily matters
do I lay any claim. The fatty or oily matters obtained as above I distil in a
retort or still under atmospheric pressure as herein-before described when
distilling the fatty acids, without, however, using any lime in the manner.

page_text: described for oleic acid. I also separate them before distillation, if they are
moderately solid, by hydraulic pressure or by other suitable means in the
manner herein-before described. Before I conclude the description of the
second and third parts of my Invention, I would remark that the fluid oily
matters, obtained according to the before-described modes of distillation,
whether in vacuo or under atmospheric pressure, require for some purposes
to be mixed with an oil which has undergone no change; the oil which I
prefer for this purpose is common whale oil, refined by the use of carbonate
of potassa;
other oils, however, may be used instead of whale oil, and they
may be used also in their original state.
The fourth part of my Invention is performed as follows:-I take five
hundred and sixty pounds of carbonate of potassa. Three hundred and fifty
imperial gallons of cold water, and two hundred and eighty pounds of lime,
and boil them together in the manner well understood for the making of
caustic potash. I then take twenty hundredweight of tallow and the above
solution, and boil them together for one hour, and allow the soap thus formed
to get thoroughly cold. When this has taken place I pour on the soap as
much cold water (the nearer 34° or 35° of Fahrenheit the better), as will
make it into a moderately thin paste, and stir the water in thoroughly in order
to effect a perfect incorporation, and pass the whole through a sieve to break
any clots or lumps which may escape the stirring. I now run the mixture
into the filtering apparatus to be hereafter described. The fluid part contain-
ing oleic acid in combination with potassa, together with the glycerine and
the impurities of the fat, pass through the filter, leaving the stearic and
The fluid I boil with lime as
margaric acid combined with potassa behind.
herein-before described for purifying tallow by carbonated alkalies, and the
compound of oily matter and lime I decompose by weak sulphuric acid in the
manner of the "stearine wax" manufacturer. The solid matter obtained by
the filter may now be decomposed directly by diluted sulphuric acid, but I
prefer boiling it with lime, which by its superior affinity seizes on the solid
fatty acids, leaving the potassa free. I now boil the lime compound with weak
sulphuric acid, and at once obtain a stearine wax" adapted for making candles
without the employment of hydraulic pressure. The solution of potassa
obtained in this mode of preparing the fatty acids I evaporate to dryness, and
heat to redness as herein-before described, and so obtain potassa, which, by
being again made caustic, is fitted for use. Soda may be used instead of
potassa, or mixture of lime or baryta, or oxide of lead, &c., with potassa or
with soda, may be substituted for the pure alkalies, but I prefer the mode as
above stated.

page_text: Figure 1 represents a plan, Figure 2 a section taken through the line a, b,
and Figure 3 a section taken through the line c, d, of the plan of the filtering
apparatus. In each of the Figures the same letters of reference indicate
similar parts. A represents a cistern to put the material to be filtered into.
B, B, B, B, pipes communicating from the cistern A to the pipes C, C, C, C.
D, D, D, D, short pipes, with the pipes C, C, C, C, to which the filtering
bags E, E, E, are tied. These bags E, E, E, E, I prefer making and using
as follows: Each bag I usually make six and a half feet long, and when
distended in the manner shewn in the Drawing, six inches in diameter. I
employ two materials for the bags, one very close twilled cotton, the other
very strong linen fabric. The twilled cotton, which is a very good filtering
material, I find not strong enough to resist the pressure I employ, I therefore
enclose the cotton bags in linen bags, and in order the better to sustain the
pressure I make the linen bags a little smaller (say one inch in diameter)
than the cotton bags. The bags I employ are open cylinders, one end of
which is tied permanently to the short pipes D, D, D. The other end is tied
by a string or other means during the process of filtration, as shewn in the
Drawing.
The operation is continued
produced from the filtered
I will now proceed to describe the process of filtration. Into the vessel A
I put the material to be filtered. I remove the plugs a, a, a, a.
It passes
down the pipes B, B, (which I prefer to be about six feet in length, so as to
obtain the desired pressure) into the pipes c, c, and from thence through the
short pipes D, D, into the bags. The fluid part filters through the bags, and
from thence it falls into the troughs F, F, F, F.
until the bags are filled with the solid matter
material, when the plugs a, a, are put in and the bags allowed to drain.
After they have ceased to drip the strings by which they are tied at their
lower ends are removed, and the solid matter is squeezed out. When this is
done the lower ends of the bags are again tied, the plugs a, a, a, a, are
removed, and the filtration goes on as before.
I will now describe the process of distillation in vacuo, as referred to by me.
Figure 4 represents a section of an apparatus constructed according to this
part of my Invention. The operation of distillation in vacuo is now so well
understood by being employed for many years in sugar refining, as to require
only a very brief description from me. a represents a vessel heated by steam
passing through a coil of pipes or other suitable means. b is a pipe commu-
nicating from the vessel a to the vacuum pan. c represents the vacuum pan.

page_text: c¹ is a barometer for ascertaining the vacuum, a thermometer for ascer-
taining the temperature. d, a small cylinder in the top of the vacuum pan.
This cylinder has a cover d' air-tight, which serves the purpose of a man hole.
is a glass tube communicating at its upper and lower end with the vacuum
pan for the purpose of ascertaining the quantity of material in the pan.
c is the proof stick. e is the pipe through which the vapour from the
vacuum pan passes in order to be condensed by the jet of water from the
pipe f, from whence it is thrown out by means of an air pump 9, through
the open trough h, into the vessel i. I would remark that a pipe might be
employed instead of an open trough, although I prefer an open trough, as it
enables me to inspect the mixture as it comes from the pump. j is a small
cylinder attached to the pipe e to receive any of the material which might
boil over. is a glass affixed in the side of the cylinder j in order to indicate
the quantity of material in it. , a "steam jacket" for heating the cylinder
when required; and is a cock for drawing off the material from the cylinder j.
k is a valve for the purpose of opening and closing the communications with
the air pump. 1, a furnace which is raised or lowered by means of a rack
and pinion, or other suitable means. ',, are upright bars, against which
rollers run in order to guide the furnace in its ascent or descent.
I will now describe the mode of using this apparatus. Into the vessel a
I put the fatty or oily matters to be distilled, and heat it by means of the
coil of pipe as high as the steam employed will admit. I now open the
valve, communicating with the pump g, and as soon as a good vacuum
is formed, which is indicated by the barometer, I open the cock in the supply
pipe b, and draw over as much of the fatty or oily matters as will nearly
half fill the vacuum pan c, then the cock is to be closed. When this takes
place I raise the furnace by means of the rack and pinion. As the fatty or
oily matters evaporate fresh material can be added through the supply pipe b.
The distillation can be prolonged for a very considerable length of time;
the time will, however, depend in a great measure on the quantity of impuri-
ties existing in the fatty or oily matters undergoing the operation of
distillation. The "proof stick" is for the purpose of examining from time
to time the consistency of the material in the vacuum pan. The vessel i is
a mere receiver for the mixture of fatty or oily matters, and water which is
thrown out by the air pump during the operation. From time to time the
water which separates in the receiver from the fatty or oily matters may be
drawn off by means of the cock 22.
Having thus described the nature of my Invention, I would have it
understood that what I claim is,

page_text: First, the mode of refining fats and oils by means of carbonated alkalies
as herein described, in order to obtain common candles of a better quality than
is now made, and to improve oils.
Secondly, I claim distillation in vacuo of all fatty and oily matters, and all
the bodies derived from them directly or indirectly, by means of any agent or
agents, or by any process or processes.
Thirdly, I claim the distillation and, when requisite, the repeated distil-
lations under atmospheric pressure of fatty acids and their products. And also
of certain fatty or oily bodies obtained from those bodies commonly called soaps,
when such soaps have been submitted to distillation under atmospheric pres-
sure. And,
Fourthly, I claim the mode of separating the fluid from the solid parts of
fats and oils by taking advantage of the different degrees of solubility which
such bodies offer when converted into salts as herein described.
In witness whereof, I, the said George Gwynne, have hereunto set my
hand and seal, this Tenth day of September, in the year of our Lord
One thousand eight hundred and forty.