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

page_text: TO ALL TO WHOM THESE PRESENTS SHALL COME, I, GEORGE
GWYNNE, of No. 3, Portland Terrace, Regent's Park, in the County of
Middlesex, Gentleman, send greeting.
WHEREAS Her present most Excellent Majesty Queen Victoria, by Her
Letters Patent under the Great Seal of Great Britain, bearing date at West-
minster, the Fifth day of November, in the fourth 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, adiñors, and assigns, or such others as I,
the said George Gwynne, my exors, adññiors, 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 the Isles of Jersey, Guernsey, Alderney, Sark, and Man, and also
in all Her said Majesty's Colonies and Plantations abroad, my Invention of
"IMPROVEMENTS IN THE MANUFACTURE OF CANDLES, AND IN 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 of my
said Invention, and an 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.
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 ascer-
tained 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
hetter 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 pro-
duction 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, when 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 hundredweight 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 con-
siderable 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 ebulli-
tion 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
settled into the lower part of the
the water and carbonate of potassa will have
vessel, from which they are drawn off' by a cock at the bottom. For distinc-
tion'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 pre-
sently, as also the mode I adopt for using the "Iye" over again. After the
lye is drawn off, as above described, I transfer the tallow, which has a soapy

page_text: 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 carbonate potassa, and raise the temperature to 110°)
Fahrenheit. I incorporate 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 200° of Fahrenheit, when the steam is shut off, and the mix-
ture 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 excep-
tion: 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 200° of 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 temperature raised to 200° Fahrenheit. After
standing a day, the oil is to be drawn off. It will be found to have lost its
soapy appearance; but it is still slightly turbid. This turbidity should be
removed, either by filtration or repose, before it is fit for use. I prefer allow-
ing 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 the
fresh carbonate of 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 usc, is as
follows:-I bring the "lye" to the boiling point, and carefully add thin cream

page_text: "
of lime until the whole of the oily matter is removed. This is easily ascer-
tained 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 "Iye." Having removed 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." 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 car-
bonated 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 colour of the oil very much. As an
instance, rape oil, after being refined by carbonate potassa, is as dark coloured,
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 tempe-
rature as readily as possible to about 490 degrees of Fahrenheit. I take care
never to exceed 500 degrees. When cold, the oil will be found exceedingly
pale in the colour, 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 exists, as acids in fats and oils having their acid properties neutral-
ized by the glycerine, in the same manner as soda neutralizes sulphuric acid.
It is also known that there are several methods of obtaining the fatty acids;
it is farther 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
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

page_text: havo 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 tempe-
rature 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 materials should be added through the supply pipe b.
The distilled product thus obtained will be better applicable to the manufac
ture of candles, and is to be used in like manner to the same material when
not subjected to distillation in vacuo. The fluid matter (tallow oil) obtained
as above described, or by any other convenient method, I also submit to distil-
lation in a vacuum pan, as above described. The distilled oleic acid, on cool-
ing, 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 hundred weight of the oleic acid. This variation
depends on the state into which I wish to convert the oleic acid. Six pounds
per hundredweight I find sufficient to change. the oleic acid completely, so that
it neither turns test-paper nor decomposes carbonate of soda. I seldom, how-
ever, exceed two pounds per hundredweight, as I find that sufficient for
practical purposes.
The following is the mode pursued 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 hundredweight 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 it to distillation.
I reserve about the first three fourths of the product for use, and the other

page_text: 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 linie absolutely necessary in distilling 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 atino-
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 I do 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 coid 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 refrigerator. It will be advisable to have a thermo-
nieter 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 350°, and it boils quite
violent at 500° of Fahrenheit. 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 150° of Fahrenheit for some days. The oleic 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 distil
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 "E stearine wax," which is to be got rid off in the
manner before described.
Another method is, to take tallow, or any other fat or oil, and treat it with

page_text: about one fifth of its weight of concentrated sulphuric acid (" oil of vitriol ").
It it be a fat such as tallow which is to be operated on, it should be melted,
and when the temperature has sank to about 105° Fahrenheit the sulphuric
acid is to be very slowly added. It 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 á quantity of water, about equal in bulk to the fat or oil, heated to about
120° of Fahrenheit if for tallow, (for oils, liquid at the ordinary temperature
of the atmosphere, 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 apparatus 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 atmo-
spheric pressure. I may here remark, that oils and fats, treated by concen-
trated sulphuric acid, are very troublesome 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 a 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 bodies do I lay any claim. The fatty
or oily bodies, 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 described for oleic acid. I also

page_text: 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 Inven-
tion, 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 under-
gone 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 carb. potassa, three hundred and fifty impérial
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 84° or 85° 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 incor-
poration, and pass the whole through a seive 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, containing oleic acid in combination
with potassa, together with the glycerine and the impurities of the fat, pass
through the filtor, leaving the stearic and margaric acid, combined with
potassa, behind. The fluid I boil with lime, as 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 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 a mixture of lime, baryta, or oxyde
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: DESCRIPTION OF THE FILTERING APPARATUS..
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, the plan of the filtering
apparatus. In each of the Figures the same letters of reference indicate
similar parts.
B, B, B, B,.
A represents a cistern to put the material to be filtered into.
pipes communicating from the cistern A to the pipes C, C, C, C. D, D, D, D,
short pipes, cast 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 6 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 twelled cotton, the other very strong linen fabric.
The twelled 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 sinaller, say ono 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.
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, passing down
the pipes B, B, (which I prefer to be about six feet in length, so as to obtain
the desired pressure). into the presses 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. The operation is continued until
the bags are filled with the solid matter produced from the filtered 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 sqeezed 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 this, 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. 6 is a pipe commu-
nicating with the vessel a to the vacuum pan. c represents the vacuum pan.
c is a barometer for ascertaining the vacuum. c, a thermometer for ascer-.

page_text: 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. 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 g, 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, 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 ³ 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. l, a furnace,
which is raised or lowered by means of a rack and pinion, or other suitable
means. ',, are upright bars, against which rollers 2 run, in order to guide
the furnice 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 heated by means of the coil of
pipe, as high as the steam employed will admit. I now open the valve k com-
municating 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 matter 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 evapo-
rate 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, how-
ever, depend in a great measure on the quantity of impurities 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, with a cock at the
bottom; 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 2.
Having thus described the nature of my Invention, I would have it under-
stood that what I claim is,―
_ First, the mode of refining fats and oils by means of carbonated, alkalies, as

page_text: 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 distilla-
tions, 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
pressure.
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 29th day of April, in the year of our Lord One
thousand eight hundred and forty-one.