AN IMPROVE- MENT IN THE MANUFACTURE AND PURIFICATION OF SPIRITUOUS SUBSTANCES AND OILS APPLICABLE TO THE PURPOSES OF ARTIFICIAL LIGHT AND VARIOUS USEFUL ARTS, AND IN THE APPLICATION THEREOF TO SUCH PURPOSES; AND IN THE CONSTRUCTION OF LAMPS AND BURNERS APPLICABLE TO THE COMBUSTION OF SUCH SUBSTANCES
Year: 1847

page_text: TO ALL TO WHOM THESE PRESENTS SHALL COME, I, CHARLES
BLACHFORD MANSFIELD, of Clare Hall, in the University of Cambridge, Esquire,
send greeting.
WHEREAS Her present most Excellent Majesty Queen Victoria, by Her
Royal Letters Patent under the Great Seal of the United Kingdom of Great
Britain and Ireland, bearing date at Westminster, the Eleventh day of
November, One thousand eight hundred and forty-seven, in the eleventh year
of Her reign, did, for Herself, Her heirs and successors, give and grant unto
me, the said Charles Blachford Mansfield, my exors, admors, and assigns, Her
especial licence, full power, sole privilege and authority, that I, the said Charles
Blachford Mansfield, my exors, adññiors, and assigns, or such others as I, the
said Charles Blachford Mansfield, my exors, adñññors, or assigns, should at any
time agree with, and no others, from time to time and at all times during the
terni of years therein expressed, should and lawfully might make, use, exercise,
and vend, within England, Wales, and the Town of Berwick-upon-Tweed, in
the Islands of Jersey, Guernsey, Alderney, Sark, and Man, and in all Her
said Majesty's Colonies and Plantations abroad, my Invention of "AN IMPROVE-
MENT IN THE MANUFACTURE AND PURIFICATION OF SPIRITUOUS SUBSTANCES AND OILS
APPLICABLE TO THE PURPOSES OF ARTIFICIAL LIGHT AND VARIOUS USEFUL ARTS, AND
IN THE APPLICATION THEREOF TO SUCH PURPOSES; AND IN THE CONSTRUCTION OF
LAMPS AND BURNERS APPLICABLE TO THE COMBUSTION OF SUCH SUBSTANCES;" in
which said Letters Patent is contained a proviso, that I, the said Charles
Blachford Mansfield, shall cause a particular description of the nature of my
said Invention, and in what manner the same is to be performed, by an instru-
ment in writing under my hand and seal, to be inrolled in Her said Majesty's

page_text: 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
Charles Blachford Mansfield, do hereby declare that the nature of my said
Invention, and the, 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 the manufacture of certain
spirituous substances and oils, and consists in treating tars and bituminous
substances, or the oils obtained from them; so that the most volatile, oily, or
spirituous substances which are contained in them are separated, videlicet, such
as are so volatile that a 'current' of air passed through them at ordinary atmo-
spheric temperatures will take up so much of their vapour as to burn with a
white flame. And this part of the Invention also relates to separating from
each other certain oils and spirituous substances which are contained in the
tar or oily matter distilled from any of the different varieties of mineral coal,
when coal is distilled either alone or mixed with other substances, either in the
process for making illuminating gas, or in any processes in which coal is sub-
mitted to destructive. distillation, which oils and spirituous substances have not
hitherto been obtained separate from coal tar and from each other. This part
of the Invention also relates to the conversion of some of the oils and
spirituous substances separated from coal tar into fragrant oil by the action of
nitric acid.
Since that part of my Invention which is applicable to bituminous oils and
tars generally is applicable particularly to coal tar, I will first describe its
application to coal tar, and will then shew its general application to other tars
and bituminous oils.
་་ ་
In order that my Invention may be most fully understood, I will first state
briefly the nature of the substances usually prepared from coal tar by distilla-
tion, and then I will explain what are the peculiar properties of the substances
which I obtain, and then I will describe the means pursued by me in order to
obtain substances possessing such properties.
It must be understood that coal tar is not a substance of invariably similar
constitution, but that, though its constituents are generally the same, their
proportions vary in different samples, and the causes of the variations therein
are not yet understood.
In the distillation of coal tar, the products which are generally recognized as

page_text: distinct and are separated from each other are ammoniacal water, oil heavier
than water, which is usually called dead oil, and oil lighter than water. The
light oil (of which the first and the last portions are sometimes received
separately, in which case the first portion only is called naptha,) comes over at
first accompanied more or less with the water, and afterwards the heavy or
dead oil, which is separated from the light oil by changing the receiver when
the distillate begins to sink in water. Some samples of tar also yield a large
quantity of napthaline, an oil which is solid at ordinary temperatures.
In distilling tar which contains much napthaline, the last portions of light
oil and the first portions of heavy oil will deposit solid matter on cooling. In
some tar, the napthaline, together with paranapthaline, another solid oil, exists
in such quantity that a large proportion of the heavy oil solidifies in cooling.
Other samples of tar contain so little napthaline that no solid matter is
deposited except by the last portions of the oil, which are distilled over at the
highest temperatures to which the retorts are generally exposed. The distilla-
tion of coal tar is usually stopped when the oil has ceased to run freely fluid,
and a yellow semi-solid matter appears. The light oil or the naptha alone is
usually rectified from some heavy oil which it contains by distillation, and is
more or less purified by treatment with acid, which is usually concentrated
sulphuric acid, if the oil be required colourless, and then forms the rectified
coal naptha of commerce; the less volatile part of the light oil, if separated, and
the heavy or dead oil, is not rectified usually, but is applied to coarse purposes,
in which a pure article is not required.
It is known to chemists that the crude oils of coal tar contain a quantity of
oily matters, some of which are acid, and have received names such as carbolic
and rosolic acids, and others; and some alkaline, which have been called aniline,
picoline, pyrrol, &c.; and besides these an oil, which by exposure to the air
becomes converted into a brown resinous matter. The object of the processes
of purification of the oils has been to remove these substances. The nature
and properties of the neutral oils, some of which constitute the rectified coal
naptha, has not hitherto been known, except that they are hydrocarbons, that
is, composed of hydrogen and carbon alone, and that the naptha has been
supposed to be a mixture of several such bodies. I have thought it necessary
to state the above facts in order more readily and clearly to define the nature
of this part of my Invention, which consists of manufacturing certain hydro-
carbons and other substances from tar.
In speaking of temperatures, I at all times refer to the centigrade thermo-
metrical scale (known also as that of Celsius), in which the freezing point of
water is marked 0° and the boiling point of water 100°.

page_text: If the unrectified light oil of commerce be distilled without water it generally
commences to boil at about one hundred degrees, and continues to distil till
the temperature of the boiling fluid reaches two hundred degrees, or there-
abouts; the last portions often become solid as they cool. The rectified naptha
of commerce of the best sort generally commences to boil at about ninety
degrees, and a portion of it (which seldom exceeds one-eighth of the entire
quantity) distils over before the temperature in the retort reaches one hundred
degrees, and the temperature gradually rises as the distillation continues till
it reaches about one hundred and sixty degrees, when the retort becomes
generally dry. The rectified naptha does not solidify or deposit crystals on
being submitted to a temperature of -20° (20° below 0°), but some samples of
the crude naptha if so treated will deposit crystals or solid matters which
consist of napthaline, and if separated will be found to remain solid at about
twenty degrees, and when fused to boil at about or somewhere above two
hundred degrees. I mention these properties to distinguish rectified naptha
from the spirituous substances which I manufacture from naptha or. tar.
And here I would state that the supposition which prevails among naptha
makers that "the strength" of coal naptha is determinable by its specific
gravity in the same way as that of alcoholic or pyroxylic spirits is entirely
fallacious. In the first place, strength as applied to these spirits means relative
freedom from water, with which they will mix in all proportions, and the
specific gravity and volatility of the mixture are respectively in direct and
inverse ratio to the amount of water in the mixture, so that the specific
gravity is a true index of the strength of such spirits; but the term "strength
can have no corresponding meaning as applied to coal naptha or spirituous
In the second
hydrocarbons, which are not capable of dilution with water.
place, the specific gravity is no index of the volatility of the naptha or of the
quantity of the more volatile spirituous substances which it contains beyond
certain limits. If the rectified naptha has a specific gravity above 875, taking
water to be 1, it may be considered as a sign that it still contains napthaline
or some other oil which boils at a temperature above two hundred degrees, or
some of the impurities which are removable by acids, and so far the specific
gravity is a test of the volatility of the naptha. But the neutral oils and
spirituous substances which compose the pure naptha (that is, when consisting
only of hydrocarbons,) are all nearly of the same specific gravity, videlicet,
from 85 to 87, and in practice the specific gravity of the naptha is rarely
reduced so low as 86, and in the state of purity in which the spirituous
substances are obtained by rectification sufficient for ordinary purposes.
have found the most volatile of them have a greater specific gravity than some
I

page_text: of the less volatile, so that the specific gravity is not a true test of the
volatility of naptha, and I state this lest it should be supposed that the
spirituous substances which I produce from coal tar or coal naptha are not
different from or not more volatile than ordinary naptha, because the specific
gravity of the spirituous substances manufactured by me may be the same as
or even greater than that of ordinary naptha.
I believe the only perfect test of the relative volatility of such spirituous
substances, oils, or napthas is by comparison of their boiling points, by which
I mean the numbers marked by the index of a thermometer, when the sensi-
tive part of such thermometer is immersed in the fluids, whose volatility is
required to be known, the fluids being at the time in active ebullition. The
boiling point in such matters is never constant unless the fluids be absolutely.
pure, and such purity is not easy to be attained in practice in the separation of
fluids of different volatility when dissolved in each other, as is the case with
the oils and spirituous substances in coal naptha, and it is found that the boiling
point will continually rise as the fluid boils away into vapour. The points to
be particularly noted in so ascertaining the volatility of such fluid are, first,
the point at which ebullition commences; secondly, the points about which the
largest quantity boils off; and, thirdly, that at which the whole has volatilized;:
and this test is most conveniently applied in a small glass retort with a tubulure
closed by a cork, through which a glass mercurial thermometer passes, the
bulb of such thermometer being placed below the surface of the fluid which
is to be maintained in ebullition. The volatility of hydrocarbons may also
be roughly estimated in some cases by placing a few ounces of the fluid
in a bottle closed by a cork, through which two tubes of about one-eighth of
an inch bore pass, one terminating below and the other above the surface
of the fluid; on a stream of air being forced through these tubes, entering by
the former tube and escaping by the latter, and a lighted match being applied
to the orifice of the latter, by observing the magnitude and the proportion of
white light in the flame, if any, which appears at the mouth of the tube; and
this apparatus I shall call a "test bottle" when I subsequently refer to it;
and in some cases the non-volatility of hydrocarbons may be ascertained by
their non-inflammability at the surface on approach of a lighted match.
I will now proceed to state what are the spirituous substances and oils which
I have found in coal tar, and which I also separate more or less from each
other, or manufacture more or less mixed with each other, or with other.
substances, by the methods hereafter described.
First, I have obtained a spirituous substance which is extremely volatile,
which boils when pure at about sixty degrees or sixty-five degrees, does not

page_text: urous of amatous suren. THIS I
call alliole.,
Secondly, a spirituous substance which is less volatile than the last, which
boils when pure at about eighty degrees, and solidifies at 0°, being the only
one of the spirituous substances that can be solidified by a temperature above
-20°, having a smell resembling almonds, which I call benzole.
Thirdly, a spirituous substance which boils at about one hundred and ten
degrees, and does not solidify at -20°, which I call tolnole.
Fourthly, a less spirituous and rather oily fluid which boils at about one
hundred and forty degrees, which I call cumole.
:
Fifthly, an oil which boils at one hundred and seventy degrees, which I
call cymole..
The aforesaid spirituous substances, and oils are obtained or manufactured
chiefly from "light oil;" but the cymole is found also in "heavy oil."
And, sixthly, I have found in the heavy or dead oil an oil which when pure
boils at about two hundred and forty degrees, and is of specific gravity 900,
which I call mortuole.
I now proceed to state how these substances may be obtained, first remarking.
that I shall describe other properties of some of these spirituous substances and:
oils when treating of the preparation of each.
And, first, I will describe the manufacture of alliole. This spirituous sub-
stance may be separated either from coal or from coal tar, or from the most
volatile part of the oil distilled from coal tar. I obtain this spirituous sub-
stance by reserving the first portion of oil which passes over on distilling the'
tar, or the most volatile oil distilled from the tar in the ordinary manner; and
it is convenient to separate the first portion equal to one-eighth of the light-
oil or naptha which is expected from the retort, but the smaller the quantity
set aside at first the purer and more volatile will the spirituous substance be.
It is convenient sometimes to continue to receive the distillate so long as a
sample taken from it will yield a flame 'entirely white on 'igniting a current
of air passed through it, as above. described in respect to what I have called a
test bottle, and this applies equally to the rectification by steam or by simple
distillation with or without water. By repeating this process with' the portion
set aside at first and again reserving the first portion, a more volatile spirit
may be obtained, and this will be more volatile the oftener the process is
repeated. The residue which remains each time may be added to the common
naptha; and in so treating the oil or naptha I prefer to distil the oil or naptha
in a retort by heat, applied without admitting steam or water into the oil or
naptha, and to use a thermometer inserted in the retort, or so connected with

page_text: it as to indicate the temperature within the retort; and I prefer to set aside
separately those portions that distil over while the temperature of the naptha
is rising through successive intervals-of temperature. By this means I
separate the naptha into several oils and spirituous substances, differing in
respect to their boiling temperatures, and by repeating this process several
times on the first products I obtain a considerable quantity of a very volatile
spirituous substance, whose boiling temperature is between sixty degrees and
eighty degrees, which does not solidify by the application of cold about -20°,
(that is, twenty. degrees below 0°). This process may be considered tedious,
but it yields a very volatile spirituous substance as a result, and a similar
process is applicable to obtaining in" a more or less
pure state the other
spirituous substances and oils before mentioned. Or I apply to the coal tar
or crude naptha any of the usual processes which are well known, and which
are applied to the distillation and rectification of spirit of wine, the residue
in the case of spirit of wine being a watery fluid and in this case tar or oil:
As what relates to rectification applies equally to the benzole as to the alliole
in coal 'naptha, and the benzole is the more important and more abundant
product, I shall now pass on' to the methods of obtaining benzole, 'observing
that 'the same 'methods apply to alliole, except that when alliole is required
separately, the first and most volatile portions, videlicet, such as distil over,
below or only a little above eighty" degrees, must be reserved alone, while
for benzole the temperature is allowed to rise higher before changing the
receiver.
The same methods apply to obtaining the volatile spirituous substances from
other tarry and bituminous and hydrocarbonaceous matters, such as wood tar,
petroleum, mineral naptha, oils distilled from bituminous schist, from caout-
chouc, and other such matters; and it may always be ascertained by a single
experiment with a small retort and thermometer, as above mentioned, whether
any sample of such matters contains sufficient of spirituous substances to
render it worth distilling, it being observed whether a large or small fraction
of the substance .distils over at a temperature below one hundred degrees;
except that when the application is made to substances other than coal tar or
coal naptha, what said of alliole and benzole must be considered to apply
to spirituous substances of nearly similar volatility, but not necessarily corre-
sponding in other properties to alliole and benzole. The more perfect the
system of rectification the more free will the spirituous substance be from oils*
having less volatility; and for the preparation of benzole, such mode or modes"
of rectification are preferable as will allow as much as possible of a very
volatile spirit, which boils when pure at about eighty degrees, to pass over in

page_text: vapour, and will keep back the vapours of the less volatile oils. The process
of rectification which I recommend is one in which the tar, crude light oil, or
crude naptha (but I prefer to use the crude naptha or light oil of tar) is
placed in a retort, which is heated either by the direct application of fire, or by
steam carried through it, either in closed pipes, or by a pipe opening into the
bottom of the retort; the vapors from the retort are conducted through a head;
in which a partial condensation of the less volatile vapours takes place, so that
these are returned in the liquid state either to the retort or to a separate
receiver, and the most volatile vapours are allowed to pass on to a condenser,
which is kept as cold as possible, and are then received separately; and I
recommend that the first condenser or head consists of a worm or chamber
with a lower opening, by which all condensed oil may flow back freely into the
retort or other vessel, with an upper opening or pipe to conduct the uncon-
densed vapours to the next condenser; and I recommend that on the first
distillation this upper condenser should be surrounded with water, which should
not be changed, but should be allowed to rise in temperature as the distillation
proceeds till it boils; or there may be two or more such vessels, in each of
which a partial condensation may take place, so as to rectify the spirituous
matters by one distillation, each being connected, if required, with a separate
special receiver for the less volatile part therein condensed; and the apparatus
may be so arranged that the vapors from the retort or preceding condenser
either may or may not pass through the fluid in each succeeding receiver; and
in case more than one such partial condenser is used, I recommend that the
temperature of that nearest the retort be allowed to rise till the water surround-
ing it boils, and the temperature of the last, or that farthest from the retort, be
kept at or below fifty degrees or sixty degrees if alliole be required, or eighty
degrees or eighty-five degrees if benzole be required, or that the temperature
in the last partial condenser be kept below sixty degrees till vapors have.
ceased to escape from it to the final condenser, which will be known by the
cessation of distillation at the final receiver; and then the fluid in the final
receiver being set aside as alliole, the temperature in the last partial condenser.
may be allowed to rise again till it reaches eighty degrees or eighty-five
degrees, and the distillate received as benzole so long as it continues to run.
I recommend that the size of the head or partial condenser, if only one be
used, be of or about the same proportion to the size of the retort as the
condensing apparatus of an ordinary still bears to the still itself, but the
water surrounding the head may be in much smaller quantity than is necessary
in such part of an ordinary still. If more than one partial condenser be used
they may be proportionably smaller; and when I use the term "head".

page_text: I would have it understood that I use it for brevity, to express a partial
condenser placed over a retort, in which an inner condensing chamber is súr-
rounded with water, or sometimes with oil, contained in an outer vessel. If
this proportion be observed, it will usually be found that the distillation will
proceed regularly, while the temperature of the water in the head gradually
rises, and that distillation will cease when the water in the head begins to boil.
Distillation may then be continued, either by drawing off the water from the
head, or by opening another neck attached to the retort, through which the
remaining naptha may come over, which will not differ much from ordinary
naptha in any of its usually recognized properties. I then repeat this process
any number of times, according to the degree of purity and volatility of the
spirituous substance required, or, as before stated, by means of successive
partial condensers. I obtain the requisite purity by one operation, and I
regulate the temperature of the water surrounding the head by the volatility of
the spirit required. The cooler the head be kept, the more volatile and the
less in quantity will be the spirit obtained. And I have two methods of ascer-
taining the volatility of the spirit which is distilling over at any time: first,
by a thermometer, which is either inserted in the retort through its side or
cover through a cork or stuffing box, or is kept loosely in a closed tube, which
projects from the side of the retort into the interior, which tube should be kept.
corked to prevent access of cold air to the thermometer (and in this case the
thermometer will usually' shew a temperature two or three degrees lower than
the true heat of the boiling fluid); or the bulb of the thermometer is placed in
a small chamber, connected with the upper part of the retort by a short neck,
in which is a cock, by turning which vapour may be allowed access. to the
thermometer; or the thermometer may be attached, if successive partial con-
densers and receivers be used in the same manner to the last partial receiver,
through which the vapor passes before entering the last head or partial
condenser. And here I may remark, that the more nearly the temperature
of the retort on the second or any subsequent rectification, or if the succes-
sive rectifications be conducted by one operation, the temperature of the
last chamber or receiver through which the vapor passes before passing
through the last partial condenser, approximates to eighty degrees, while
the contents of the retort are in active ebullition, the more nearly will the
fluid distilling at the same time approach to the nature of benzole, and
the more easily will such spirit be purified by refrigeration, according
to the method hereafter to be described. And I recommend that when
benzole be required for purification by freezing, such temperature be not.
allowed, to pass ninety degrees before the receiver is changed, and as the tem-

page_text: perature rises in the retort the distillate will be less and less volatile. And the
other method.in which I ascertain, the volatility of the spirit is by the flame
yielded by the "test bottle with a current of air, as above described. If a
portion of the first and therefore most volatile distillate from the naptha be
placed in such a bottle, and common, air be blown. through the tube which
reaches below the level of the fluid, as may be done conveniently from the
mouth, and if a lighted match be at the same time applied to the mouth of
the other tube, the air on escaping will have taken up so much of-the-vapor
of the spirit that it will burn with a white flame. If samples be taken as they
come from the still at intervals and placed in such a test bottle, it will be
observed that the air will still burn with a white flame after many such samples
have been tried. As the temperature in the retort rises, however, it will be
observed that the test bottle shews a diminution of the whiteness in the flame,
which becomes more and more blue from below upwards, till only the tip of
the flame will be white, next the whiteness will disappear, and the flame will
become entirely blue And if the distillation" be conducted in a still which
permits the whole of the naptha to pass over, it will be observed that when the
operation has been continued to a certain point, the test bottle will no longer
yield any flame. I find it convenient sometimes to regulate the change of
the receiver by the observation of the flame, according to the volatility of the
fluid required. It will be found that all that comes over on the second-
rectification of the spirituous matter below ninety degrees will yield a good
white flame, and about one hundred degrees about one-half or more of the
flame will be-white. And here I will further state the properties of the dis-
tillates obtained as the temperature "advances, which it is the object of my
Invention to separate from each other and to purify. The first portion of the
distillate will generally be an extremely volatile spirituous substance, which
when purified is of a peculiar alliaceous smell, somewhat resembling that of
bisulphuret of carbon. It boils when pure at about sixty-five degrees or seventy
degrees, and is changed by mixture with concentrated sulphuric acid, which
forms a compound with it. It does not solidify at twenty degrees below 0°
It will usually be obtained mixed with a certain quantity of the spirituous
substance which next follows in the scale of boiling points; to obtain it mode
rately free from which, it is convenient to receive for alliole all that comes over
before the boiling temperature in the retort is ninety degrees on the first recti
fication, and eighty degrees on the second; or, if distilled through a condensing
head, before the temperature of the head has passed sixty degrees; but by
extending the "distillation from this spirituous substance a little further its
volatility is but slightly diminished, and I obtain a mixture of it in any propor-

page_text: tion with the spirituous substances of higher boiling points. If it be required
to obtain alliole from the naptha, the naptha should not have been treated with
concentrated acids before distillation, since this substance is for the most-part
changed by such substances.:: Immediately following alliole in the scale of
boiling points is benzole, which when pure boils at eighty degrees, and
becomes solid at 0°; it exists in the naptha in far larger quantities than the
preceding oil, amounting in some cases to one-eighth of the light oil obtained
from the tar; it has a smell somewhat resembling almonds: when pure, and is
extremely volatile; it is not destroyed by agitation with sulphuric acid (by
which I mean oil of vitriol), and it is convertible into an oil resembling oil of
bitter almonds by nitric acid. To obtain this oil in a state of moderate purity
is the chief object of the rectification to 'which I subject the naptha. I obtain
it pure by a process hereafter to be described: In the state of moderate purity,
in which it is obtained by the processes of rectification above described, it is of
the same volatility as alcohol; which it resembles in some of its properties; but
it is more nearly allied to ether, as a substitute for which it is generally' appli-
cable. At common temperatures it yields so much of its vapor to a stream of
air passed in contact with it, that the air will continue to burn with a white
flame till the whole of the fluid is volatilized, and this will distinguish. it as well
as alliole from any naptha, however highly rectified; which has hitherto been
manufactured from coal tar; for though some of the naptha of commerce.is so
volatile as to yield a white flame with air passed through it, yet, before the
whole of any such naptha has volatilized, a fluid will remain, which will either
yield no vapour to the air so passed through it, or only.so:much as to yield a
blue flame. As obtained by rectification from the still, this spirituous substânce
will, however, usually be mixed with a greater or less quantity, of alliole, and
of the next spirituous substance, namely, tolnole, which generally exists in the
naptha in large quantities, and which boils when pure at about one hundred
and ten degrees; a considerable quantity of this spirituous substance: may be
obtained by setting aside separately the last portions which pass over through
the head in which the water is allowed to boil. After the temperature in the
retort has reached one hundred degrees, or if more than one partial condenser
be used, by reserving."the fluid which will be found in the intermediate:
receivers or distilling vessels in which, the temperature being between ninety.
degrees and one hundred and ten degrees, the benzole has been distilled off,
while the cumole, together with part of the tolnole has been kept back in the
retort by the first head; and a further portion may be obtained by setting aside.
the first portion of distillate which comes over on distilling. through a common
retort neck, with or without water or steam, the residue kept back in the retort

page_text: by the head on the distillation of the benzole, and it is best to set aside for
tolnole what comes over before the boiling point reaches one hundred and thirty
degrees. This spirituous substance is not destroyed by agitation with concen-
trated sulphuric acid, and by concentrated nitric acid it is convertible into an
oil somewhat similar to oil of bitter almonds; a current of air passed through
it burns with a pale blue flame, and in an open vessel it will take fire on the
application of a lighted match to its surface; it is of about the same volatility
as good rectified naptha, and is applicable to many purposes in which a volatile
solvent is required. The residue of the crude light oil, after the separation of
the aforesaid spirituous substances, consists chiefly of two oils, one of which,
videlicet, cumole, boils at one hundred and forty degrees, being therefore more
volatile than oil of turpentine, whose boiling point is about one hundred and
sixty degrees; and the other, videlicet, cymole, which boils at about one hundred
and seventy degrees, and is therefore less volatile than oil of turpentine.
Cumole is changed by treatment with concentrated sulphuric acid, so that if a
quantity of it, or of the naptha, or oil of coal tar containing it, be agitated with
a quantity of concentrated sulphuric acid, a proportion of cumole equal to about
the bulk of the sulphuric acid employed will be converted into a resinous
substance, which will become partly dissolved in the acid; and by concentrated
nitric acid it is convertible into an aromatic oil, somewhat resembling oil of
cinnamon in taste and smell, or into an acid resembling benzoic acid, according
to the strength of the acid, and to the duration and temperature of treatment
with such acid; and this oil, when the spirituous substances having lower
boiling points have been sufficiently separated from it by distillation, will not
yield to air passed in contact with it in a test bottle vapour sufficient to
afford a flame, neither will it take fire on the surface when of the ordinary
temperature of the air upon a lighted match being plunged into it in an
open vessel. If, however, all the spirituous substances be not separated from
it, but only the alliole and a large proportion of benzole, it will, with the
tolnole which is mixed with it, have most of the physical characters and
properties of the common naptha of commerce. It should be received, if
required, separately when the boiling temperature in the retort is between
about one hundred and fifty degrees and one hundred and seventy degrees
on the first distillation of the light oil, and on subsequent rectifications at
temperatures nearer to one hundred and forty degrees. It will, however,
require many rectifications before it has been so far freed from the spirituous
substances as to yield an oil boiling at one hundred and forty degrees, and not
having the property, like common naptha, of catching fire on the surface on
the approach of a lighted match. The oil next following in the scale of boiling.

page_text: points, videlicet, cymole, which boils at about one hundred and seventy degrees;
also has not the property, like common naptha, of catching fire at the surface at
the ordinary temperature of the atmosphere, but will extinguish a match or
lighted taper if plunged into it, and this oil, which is obtained chiefly from
such portions of the oil of tar as boil at temperatures higher than the
previous substance, is more easily obtained free from spirituous substances; and
when I require to obtain a volatile oil lighter than water, and characterised by
not inflaming on the application of a lighted match to its surface, I usually
manufacture an oil which is a mixture of cumole with cymole, and to this
mixture, or to the oil having such properties and prepared from coal tar or the
oil of coal tar, I apply the name of camphole.
I now proceed to describe the method which I find most convenient for
obtaining such a product. In distilling the naptha from which all the benzole
has been separated by the processes above described, or in distilling the
naptha or light oil from which benzole has not been separated, for the purpose
of obtaining camphole, the ordinary methods of applying fire or passing
steam through the naptha are applicable, unless it is intended to regulate the
distillation by the boiling point of the fluids in the retort (and in that case
the distillation by steam is not applicable), and if the thermometer be not
used for this purpose, the aforesaid property of non-inflammability at the
surface affords a convenient test for the time when the receiver should be
changed for the separation of camphole; and I apply this test, by occasionally
collecting a small quantity of the distillate as it runs from the condensing
apparatus, from which it should run perfectly cold in an open cup or saucer,
and plunging into it a lighted match or taper, when the fluid no longer catches
fire on the surface, but extinguishes the light, I change the receiver and
collect now for camphole. I now continue to receive this oil until either the
temperature in the retort reaches two hundred degrees or one hundred and
ninety degrees, or till the specific gravity of the oil reaches nearly that of
water, or till common soft solder placed on the retort melts. Either of these
indications shew that an oil, having a higher boiling point and greater density
than the product which I call camphole, is coming over. Camphole in the
crude state may have a specific gravity varying from 880 to 980; or if the dis-
tillation be continued farther to 1000, and this increase of density is owing
to the mixture of denser oils, especially of napthaline, when pure (that is, when
consisting only of hydrocarbons lighter than water), its specific gravity is not
higher than 87, though to reduce it to this purity it requires many rectifications.
It is partly destroyed by strong sulphuric acid, the cumole which it contains
being converted by that acid into a viscid resinous substance; it is violently.

page_text: acted, on by..strong. nitric acid, which converts it into heavy oil or into acid
substances, in a manner analogous to the action of that acid on the oil boiling
at about one hundred and forty degrees. This oil is generally accompanied by
creosote, whose boiling point is about two hundred degrees. I rectify this oil
by repeated distillation, either setting aside the first portions which come over
on re-distillation, and which will be more volatile than the rest of the oil, and
will take fire on the surface, or allowing these first portions to be mixed with
the subsequent portions; and on each such distillation I prefer to cease
receiving when the temperature in the retort reaches one hundred and ninety
degrees or two hundred degrees; or, in place of the above, I rectify the oil by
one operation, in a manner analogous to the method recommended for distilling
the more volatile substances from naptha, except that it is necessary in this
case to surround the still head with a fluid having a higher boiling point
than that of water; and for this purpose I prefer oil, either volatile or fixed;
if fixed oil be used, I maintain the temperature of the oil surrounding the
head at a température which shall allow all the vapours of the camphole to
pass over, but as little as possible of any substance having a higher boiling
point, and for this purpose I prefer to keep the temperature of the head at or
below one hundred and seventy degrees, by an occasional supply of cold oil
replacing oil which has been heated by the vapour which it condenses; and if
volatile oils be used for the partial condensation, I prefer to take some of the oil
of coal tar which has been distilled from till the temperature of the boiling fluid
has reached one hundred and seventy degrees, so that on heat being applied
again to the oil it shall commence to boil at one hundred and seventy degrees,
and I place this oil in the outer vessel which surrounds the condensing chamber
in the head of the retort, which outer vessel is not in this case open above, but
is fitted with an ascending tube or neck, by which its own vapours are conducted
up to a similar head, immediately above which second head is surrounded with
water, kept as cold as possible, so that all vapour that is evolved from the oil
of the lower condenser is condensed and returned to the lower condenser, so that
the oil in the lower or proper condenser will remain constantly at one hundred
and seventy degrees, or at any temperature at which its previous ebullition
may have been arrested. In the rectification of the spirituous substance the
residue will sometimes contain a quantity of camphole, which may be sepa-
rated if required in the same manner. Further, the product so obtained as
camphole by the method above described may frequently be mixed with ä
certain quantity of the volatile spirituous part of the naptha or of common
coal naptha without becoming inflammable at the surface; and it is convenient
sometimes to make such mixture, as the mobility and lightness of the oil is

page_text: thereby increased, but if too much of the volatile foil be added, the mixture:
will become too inflammable: Thus far of the crude oil of coal tar, which, is.
lighter than water... I further apply my improvement to the treatment of the.
heavy oil of tar, commonly called "dead oil. I submit this oil to distillation,
preferring, however, to separate it, as it is distilled from the tar into two
portions, a first and second, each of which should be about equal to the half
of the quantity of dead oil which the tar should yield, the, object of this being
to facilitate the separation from the heavy oil of a considerable quantity of the.
light oil, last described, videlicet, camphole, which will remain in the heavy oil,
and almost entirely in the first half, and which is more easily separated from
the first half than from the whole of the dead oil together. The treatment is:
the same, however, whether the heavy oil be treated: altogether, or whether the
first half be treated alone for the separation of this, light oil. I do not treat.
the second half of the heavy oil alone for, this purpose; I either submit this oil
to rectification, by means of steam passed through it, in the manner, ordinarily
practised in the rectification of the light oil, or I distil it by application of
heat to the, retort containing. the oil, either with or without the mixture of
water with the oil.., . I am aware, that the rectification of the dead oil has been
practised before for the purpose of obtaining a further quantity of fine, naptha
from the dead oil; but I must remark that I do not practice this for the
purpose of obtaining naptha from the oil, but to obtain a quantity of an oil
which differs in its properties, from naptha in not being inflammable at its
surface when, the oil is of the ordinary temperature of the air. If steam be
used, the greater part of the light oil will be carried over with the vapor of
the water, and will float on the water in the condenser, and I prefer to stop
this process when the specific gravity of the, oil so carried over reaches 940;:
or I submit the, oil to distillation in the ordinary manner, and cease receiving.
as camphole; when the specific gravity, has risen to nearly that of water, or
when the temperature reaches two hundred, degrees, or two hundred and
ten degrees, or when solder, will melt on the retort, as described when
treating of the distillation of the last portion of light oil; or I adapt a
head to the retort surrounded with condensing fluid, as described, for the
last light oil, whose limiting temperature I prefer to fix at one hundred
and eighty degrees or one hundred and ninety degrees, since the boiling
point of the same oil will be raised considerably in this dead oil by the
greater quantity of oils having higher boiling points which are present with
it, and I continue distillation so long as any vapour passes uncondensed
through this head or partial condenser. I mix this distillate, now obtained by
any of these methods, with the last distillate obtained from the light oil, as

page_text: above described, being chiefly the same oil, and characterized by being slightly
lighter than water, and so little inflammable that it will not take fire on the
surface at ordinary temperatures on the application of a match. Having
separated from the dead oil or from the first half of it as much of this oil,
which I call camphole, as can be obtained by these methods, I submit the
residue to distillation in a still suited to the distillation of a fluid having a very
high boiling point, and therefore requiring a high temperature to be main-
tained in the retort during distillation; or if the first half of the dead oil has
been treated alone for the separation of the camphole, I mix the residue of it
with the second half of the dead oil, or distil it alone; or I treat the residue
at once in the manner hereafter described for the purification of the dead oil
without previous rectification; but I prefer to distil it once or oftener before
so treating it, as by this means certain substances are separated from it which
increase its bulk unnecessarily, and which are not required to be purified;
and if so much napthaline be present in the tar as to cause any portion of the
first part of the heavy oil to solidify on cooling when kept separate, I reject
the first portions of the oil which distil over, so long as it solidifies, wlien
received in a thin film upon a cold surface, and I continue to receive the oil,
either until the distillate when received upon a cold surface again commences
to solidify, or till it begins to shew a decided yellow color, or till the tempe-
rature in the retort, as indicated by a thermometer connected therewith, in
either of the modes before described, is three hundred degrees, either of
which indications shew that the best part of the fluid oil has come over, and
that the residue contains too much paranapthaline, which is an oil solid at
ordinary temperatures, boiling at a temperature above three hundred degrees,
and which diminishes the fluidity of the oil when mixed with it, and on each
successive distillation the same précautions are to be attended to. This oil
when pure has specific gravity 900, but from the difficulty of ridding it entirely
of napthaline and paranapthaline, it is even when rectified generally rather
heavier than water; it boils when pure at about two hundred and forty degrees.
It is not easily destroyed by sulphuric acid, so that oil of vitriol may be used
in purifying it. I call this oil, when rectified and purified, mortuole.
I proceed now to that part of my improvement whereby I manufacture a
fragrant oil or oils from some of the spirituous substances and oils distilled from
coal tar. I will first state the method of treatment, which I find the most con-
venient in practice. I use a vessel capacious enough to hold about three times
the quantity of oil which is intended to be treated, and with a long narrow neck
to check any expulsion of vapour or liquid, which vessel may be of any con-
venient material that will not be injured by strong nitric acid, such as glass,

page_text: which should not be thick, lest it be cracked by the heat, which may be evolved
during the process, and glass offers the advantage of enabling the process in
the vessel to be observed.
I place in the vessel a quantity equal in measure to rather more than the
quantity of oil intended to be treated of the strongest fuming nitric acid that
can be obtained, of specific gravity at least 1.50, and I prefer to use the pure
acid free from chlorine; I place the vessel in another open vessel, which is filled
with cold water, so as to surround the first vessel and to keep it cool; I then
pour into the acid as much of one of the light oils or spirituous substances,
hereafter to be particularized, as the acid will dissolve.
The point of saturation is ascertained by observing when the liquid separates
into two layers; I then remove the vessel from the cold water, and warm it
cautiously over a gentle heat till the two layers again mix into one clear
solution; I then add a further quantity of oil, until the solution begins to
appear turbid; I then add a few drops more of the acid, till the solution is
again clear and uniform, and warm the mixture slightly for a minute or two,
not, however, allowing it to boil; I then pour the whole of the mixture into
five or six times its bulk of cold water; a heavy yellow or red oil will fall to
the bottom of the water, and should be about equal in bulk to rather more
than the light oil originally employed; I agitate this heavy oil with successive
large quantities of clean water; I allow the oil to settle to the bottom and draw
off the water after each washing, till fresh water after being thoroughly agitated
with the oil has no longer acid properties, or I wash it with a smaller quantity
of a clean filtered solution of carbonate of soda or of lime to remove the acid,
and then wash the oil after subsidence and separation with a small quantity of.
water to remove the lime or soda salt. A similar heavy oil may be obtained
from the rectified light oil of coal tar by the action of nitric acid in other ways,
as by using an acid of specific gravity a little less than 150, which will not
dissolve the oil in so large a quantity as a stronger acid, and that not without
the aid of heat; and if such acid be used it will be unnecessary to immerse the
vessel in cold water, as above described; or by agitating the oil with twice its
bulk of a mixture of the ordinary strong nitric acid of commerce with an equal
measure of oil of vitriol, but by this method the oil will not be thoroughly
converted into the required product; or by heating the oil with a mixture.of
sulphuric acid and nitrate of potash or soda; but I prefer to use the method
above described, as being simpler, and yielding a purer product.
And now I come to speak of that part of the oil of coal tar which I use for
this treatment. The ordinary rectified coal naptha of commerce, or the oil
which I have described as camphole, may be converted into a heavy oil by nitric
B

page_text: acid, and if the naptha or camphole has been previously well purified. from the
acid and basic oils of coal tar, the heavy oil so obtained will have more or less
of an aromatic or fragrant smell; but I prefer to use the volatile spirituous
substance. which I call benzole, since the oil produced from that substance has
the most pleasant odour, and for this purpose the benzole should have been
previously treated with concentrated sulphuric acid, in the manner which I
shall describe, to remove the alliole, pyrrol, and picoline, but it is not necessary
to rectify the benzole thoroughly from the tolnole, since the oil produced. from
the tolnole by this treatment is very similar in smell to that produced from the
benzole; but I prefer to use a spirituous substance which. has distilled over
while the temperature in the retort or last rectifying; vessel was between eighty
degrees and one hundred degrees, in which case the oil will be.of.a. light
yellow or orange colour, and will have an odour. similar to that of oil of bitter,
almonds, and is useful as a perfume, especially applicable to soap, or for
conferring a pleasant flavor when used in small quantities upon articles of
confectionary. When undiluted it is sweet like sugar. If cumole or a less
volatile naptha be used the colour of the heavy oil produced will usually be
red, or dark orange color, the odour of the product will be more like that of
cinnamon, and contain aromatic acids, somewhat similar to benzoic acid, will
be produced at the same time, as is also the case with cymole. Care should be.
taken, especially if the less volatile part of the light oil be used, not to allow
the action of the acid to take place suddenly, since the acid. acts with violence
on the cymole, and may expel the contents of the vessel against the person
of the operator.. .It may be convenient in this case to add the acid slowly to
the oil, instead of pouring the oil into the acid, and it is evident that the
same method may be applied to the benzole. The fragrant oil so obtained may
be rectified by distillation, if required, either by passing steam through it or
by heat applied to the exterior of the retort containing the oil, but since the
oil boils at a high temperature, videlicet, at about two hundred and ten degrees
or two hundred and twenty degrees, and is liable to decomposition if exposed
to a higher temperature, it should not be distilled over a naked fire, and it is
better to distil it by immersing the retort in a bath of sand or oil, the tempera-
ture of which is not allowed to rise above two hundred and twenty degrees. I
call the heavy fragrant oil thus produced from the light oil of coal tar
nitrobenzole.
What I claim in respect to this first part of my Invention is, the manufac-
ture from bituminous matters, by acting upon them at suitable temperatures, of
spirituous substances which are so volatile that a current of atmospheric air
(at ordinary temperatures) passed through them may, when ignited, continue

page_text: to burn with a luminous flame till all or.
r nearly all such substances are
consumed.
I also claim the manufacture from oil or tarry matters distilled from coal, by
acting on them, or on matters produced therefrom, at different temperatures of
the products herein described, which I have called alliole, benzole, tolnole,
camphole, mortuole, and nitrobenzole; and here, by alliole I mean a spirituous
substance which consists chiefly of hydrocarbonaceous matter more volatile
than benzole. By benzole I mean a spirituous substance whose boiling
temperature is chiefly between eighty and one hundred degrees, and is such
that if cooled to twenty degrees below 0%it will become in part solid. By
tolnole I mean so much of the light oil of coal tar as may remain after the
separation of the alliole, benzole, and camphole. By camphole I mean an oil
lighter than water, which, when of, the ordinary temperature of the air, will not
take fire on the surface on the approach of a lighted match, and whose boiling
temperature lies chiefly between one hundred and forty and one hundred and
eighty degrees. By mortuole I mean 'an oil whose boiling temperature lies
chiefly. between two hundred and two hundred and sixty degrees, obtained by
the method above described. By nitrobenzole I mean a fragrant oil prepared
from the oil of coal tar by the action of strong nitric acid.
And now having described the spirituous substances and oils which I manu-
facture from coal tar, or from the oils or naptha distilled from coal tar, and
the methods by which I manufacture them, I will proceed to the second part
of my Invention, videlicet, to that which relates to the purification of volatile
bituminous and empyreumatic oils, which are found in nature or produced by.
the destructive distillation of organic substances, or of mineral substances con-
taining or consisting of matters of organic (that is, of vegetable or animal)
origin, which Invention is specially applicable to the spirituous substances and
oils which are manufactured according to the first part of my Invention, and is
partly applicable to the purification of bituminous and empyreumatic oils in
general.
I will proceed to describe this part of my Invention, as specially applied to
the spirituous substances and oils particularly described in the first part of my
Invention, and as I proceed will show in what manner it is partly applicable
to empyreumatic oils in general. As applied to the purification of the afore-
said particular spirituous substances and oils, it depends partly upon their
properties, and partly upon the nature of the foreign substances which accom-
pany them, and whose presence in the different parts of the distillate depend
upon the different volatilities of these foreign substances, approaching more or
less closely to those of the oils and spirituous substances which I desire to purify.
RQ

page_text: And for the more perfect understanding of this part of my Invention, I will
state what these impurities are, of which I propose to free the hydrocarbons.
It is well known that ammonia in large quantities is present in the crude tar
oil, besides which there are several oily alkaloids, known to chemists as aniline,
picoline, pyrrol, &c., which have different boiling points, and some one or more
of these are found in all the crude oil of tar, at whatever temperature it may
have been distilled, as some are very volatile, and some are less so. All these
bodies are removable from the neutral oils by acids, which for this purpose
need not be highly concentrated. There are also certain acid oils, such as
creosote, carbolic, and rosolic acid, which are found principally in the less
volatile portions of the oil; these acids are removable from the oil by treating
it with caustic alkalies. Farther, there are some substances in the crude oil
which gradually absorb oxygen from the air, and become brown, thus giving
the well-known property of becoming dark coloured by being kept. There is
very little of this substance with the most volatile spirituous substances, and
the largest portion of it is found in the oil which boils between one hundred
and forty degrees and two hundred degrees. These substances are removed
by being at once converted by treatment with strong acids, or caustic alkalies,
or other oxidizing agents, into their brown state, in which they are no longer
volatile, and are therefore left behind on distilling the oil. There are other
substances which may be considered as impurities, videlicet, napthaline, a solid
hydrocarbon, which when pure boils at two hundred and twelve degrees, and
is therefore found chiefly in the camphole and in the first half of the dead oil;
paranapthaline, a solid hydrocarbon, which boils at a temperature above three
hundred degrees, and is therefore chiefly in the last portions of dead oil.
Besides these, the most volatile of the spirituous substances, videlicet, alliole,
since it has an ill smell, may be considered as an impurity when present in
such benzole as is required to be pure; all these, videlicet, napthaline, para-.
napthaline, and alliole are removed by a sufficient quantity of concentrated
sulphuric acid, which forms peculiar compounds with them, which it dissolves
and carries with it to the bottom of the other hydrocarbonaceous spirituous
substances, on which, with the exception of camphole, it acts much less.
powerfully.
of
I proceed now to the application of these facts to the purification of the
different oils and spirituous substances manufactured according to the first part
my Invention. If a very volatile spirit be required which is not required to
be entirely free from a slightly disagreeable smell, I take any portion of the
most volatile part of the naptha, separated according to the principles which I
haye set down; but I prefer to take for this purpose such as may have been

page_text: distilled over before the temperature in the retort in the second or third distil-
lation, or in the last distilling vessel, if a complex rectifying apparatus be
used, has risen above eighty degrees. This spirituous substance, which I call
alliole, will not be absolutely pure, being mixed with a certain portion of the
benzole, but will usually be found to be characterized by the peculiar smell of
the
pure
alliole. I add to this alliole about one-fourth its bulk of a cold
moderately dilute acid; for which purpose I prefer hydrochloric acid of specific
gravity 1:16, mixed with five times its bulk of water, but a much stronger
hydrochloric acid may be used, or oil of vitriol mixed with nine times its bulk
of water. I do not state that these proportions are absolutely necessary, but
they are convenient, the requisite condition being that the acids be not con-
centrated nitric or sulphuric acid, since these acids when concentrated destroy
the alliole in proportion to the quantity in which they are used. I agitate the
alliole with the acid in a suitable vessel, which should be nearly closed, or so
constructed as to prevent evaporation of the spirituous substance for a length of
time, which will vary with the quantity of spirituous substance which is under
treatment, all that is necessary being to keep the acid and spirituous sub-
stance in a state of intimate mixture for a sufficient time to enable the acid
to form salts with the ammonia and oily alkaloids which accompany the
crude alliole; I then allow the vessel to stand undisturbed till the two fluids
have separated; I then draw off the acid liquor, and wash the alliole by agi-
tating it with about its bulk of clean water, in the same manner as with the
acid; the alliole, if then allowed to separate from the water, and drawn off, is
fit for use. But it is convenient sometimes to rectify it again, and to allow it
to stand for some time, after careful separation from any water that may
accompany it, upon fresh burnt lime, which will remove any acid and water
that may still adhere to it.
The spirituous substance so obtained will be found to have a slightly alliacious
odour, somewhat resembling that of bisulphuret of carbon, to be extremely
volatile, and if placed in a retort and distilled should begin to boil about sixty-
five or seventy. degrees, and the greatest portion of its bulk should distil over
before the temperature from the retort arrives at eighty degrees, and the tem-
perature should then rise very fast, and the retort should be dry at about ninety
degrees, or a little above. This spirituous substance will be found to be an
excellent solvent of caoutchouc, gutta percha, and many of the resins; it will
mix with pyroxylic spirit in equal proportions, if the spirit be not too much
diluted with water, and may be used when so mixed for dissolving shellac, or
shellac and gutta percha or caoutchouc mixed, though it will not dissolve lac
in sufficiently large quantities when alone; or it may be mixed with a solution

page_text: of lac in pyroxylic spirit in similar proportions, and the proportions in which
it may be mixed with any sample of pyroxylic, spirit may be readily ascer
tained by putting a known quantity of the alliole into a graduated glass, and
pouring into it the pyroxylic spirit, at the same time shaking the mixture until
the whole of the álliole, is dissolved, and a clear transparent mixture results,
which shews no streaks of milkiness when the surface in an open glass is
slightly blown upon. The proportion or quantity of spirit which, has been
added to the alliole which was in the glass shew the proportions in which they
be mixed. Alliole so prepared also yields a brilliant light when burned by
the aid of a current of air, as described in the subsequent part of my
Invention, which relates to artificial light.
Next, of the purification of benzole, prepared from coal tar or the products
of coal tar. If this be not required perfectly free from the odour of alliole,
and if moderate purity be only required, I treat this spirit in the same manner
which I have described for the treatment of the alliole; and if it be required
for burning, with the aid of a current of air, as hereafter described, I prefer to
treat it in this manner, by which all the spirituous part is preserved intact,
while the picoline and other basic or alkaline substances, which chiefly cause
the disagreeable smell of the naptha, are removed, and I consider it sufficiently
pure for this purpose when a piece of white deal, dipped first. into the benzole:
and then into hydrochloric acid, does not acquire a red or pink colour. If,
however, a volatile substance be required as a solvent, or for any other purpose
where freedom from unpleasant odour is necessary, the treatment is different.
Instead of agitating the benzole with dilute acid, I agitate it with concentrated
sulphuric acid, in the proportion of about half a pound of acid to a gallon of
the benzole, which destroys the alliole; at the same time that it removes the
basic oils, and oxidises any of the brown forming substance which may be
present; and I prefer to add with the sulphuric acid a small quantity of nitrate
of potash or nitrate of soda, about one ounce to half a pound of sulphuric
acid, or nitric acid, or nitrous acid, or aquafortis, of specific gravity about 1.30,
in the proportion of one fluid ounce to half a pound of sulphuric acid. The
addition of the nitric acid.tends greatly to bring out the pleasant smell of the
benzole from the more perfect oxidation of oxidable substances which are.
present, and from the formation of, a small quantity of the sweet-smelling.
compound of which I have already spoken, which, when the benzole is recti-.
fied, is separated in the residue; or, instead of sulphuric acid mixed with nitric
acid or its salts, I use nitric acid, nitrous acid, or aquafortis. alone, of specific
gravity about 1.30 or 1.40, or nitric acid mixed with hydrochloric acid or nitro-
muriatic acid, in the proportion of half a pound of the acid to a gallon of the

page_text: benzole; or, instead of the nitrate of potash or soda, I use a similar proportion
of bichromate of potash; I then, after 'agitation, allow the mixture to settle,
and then draw off the benzole from the thickened acid; I then sometimes'add
to the benzole a small quantity of chloride of lime, and some moderately strong
acid, and stir the mixture; but this further deodonizing process is seldom
necessary, and whether this last process be used or not, I now agitate the ben-
zole with water, and complete its purification in the same manner as the alliole
is purified. The spirituous substance so obtained will be found to be very
volatile. If placed in a retort it should commence to boil at eighty degrees,
and the largest portion of it should come over. before the temperature in the'
retort reaches eighty-five degrees, and the retort should be dry at one hundred
degrees without leaving any residue. If subjected to a temperature of twenty
degrees below 0° (-20°), it should deposit so large a quantity of crystalline
matter as to become almost entirely solid; it should have a smell somewhat
like that of almonds. It will be found to be an excellent solvent for the same
purposes as 'alliole; being very useful for making many kinds of varnishes. If
a solution of gutta percha be made in benzole, and the solution be spread as a
varnish on a smooth surface, such as glass or porcelain, the spirituous parts
will rapidly evaporate, and will leave the gutta percha in a tough film on the
surface, which may be peeled off; and in this way, by properly adjusting the
surface, and carefully peeling off the varnish, artificial membranes applicable
to many useful purposes may be made; or by spreading the solution' on the
surface of the human body, an excellent plaister or artificial skin may be
obtained in cases in which such protection is desirable. This benzole is an
excellent solvent for camphor, essential oils, fats, wax, and many other sub-
stances; it may be used as a substitute for spirits of wine in some of the
arts, and for oil of turpentine in most of the purposes to which that hydro-
carbon is applied, having the property of far grater volatility than the
latter substance, which in many instances would be an advantage. Ben-
zole admits, however, of yet further purification, which for some purposes
it is desirable to effect, and this is accomplished by freezing. But since
for those purposes for which it would be required to be so highly
rectified it would probably be required to be as free as possible from all
foreign' oily matters, I recommend that it be again treated with sulphuric
or nitric acid, or with nitric.
acid, with or without the addition of saltpetre
acid alone, or with nitromuriatic acid, as above described; or that it be
distilled with about one quarter its bulk of a mixture of two parts concentrated
sulphuric acid, and one part of a concentrated aqueous solution of bichromate
of potash, or with a small quantity of chromic acid; 'änd I recommend that if

page_text: such treatment be repeated until the benzole, on being agitated with cold oil of
vitriol, no longer confers a dark color upon the acid, but strong nitric or nitro-
muriatic acids must not be used in so large proportion as sulphuric acid may
be used, since the benzole may be decomposed by the former acids, though not
by the sulphuric acid. When this further treatment with acid has been used,
I wash the benzole well with water or lime water to remove the acid, and distil
it either with or without the addition of some lime, and I prefer to insert a
thermometer in the retort, and to receive for refrigeration what comes over
while the temperature in the retort is between seventy-nine and eighty-eight
degrees; what comes over beyond may be mixed with some of the crude
spirituous substance reserved as purified tolnole, of which it will partly consist.
The benzole may be further rectified by distillation any number of times, and
that portion of the distillate should always in that case be reserved separately
for purification which comes over between eighty and eighty-five degrees. The
reduction of benzole to a state of further purity depends upon the property
which it possesses, and which distinguishes it from coal naptha and from all the
other hydrocarbons contained in the naptha, viz, that of becoming solid when
exposed to a low temperature, and of melting again when pure at a tempera-
ture a little above that at which ice melts. The degree of cold requisite to
solidify the fluid will vary inversely with the degree of purity which it has
previously attained by distillation. If nearly pure it will solidify at 0°; if
about half of the fluid be benzole, and the rest the other hydrocarbons of
the naptha which distilled over with it, the benzole will crystallize out of the
solution when exposed to a temperature of -20°; and I may state that,
generally, if the crude benzole obtained by once distilling the first runnings
of the coal naptha, or the whole light oil, or the rectified naptha, as
described in the first part of my Invention, (viz, from a boiler surmounted
by a head surrounded with water, which is allowed to become heated to
ebullition,) be again rectified in a similar apparatus, and the first portion of
the distillate equal to one-third the quantity placed in the retort, (especially
if the very first one-sixteenth portion be set aside separately as alliole, which
does not solidify at 0°,) or, if that portion which comes over while the
temperature in the retort is rising from eighty degrees to ninety degrees be
reserved as benzole, that portion so received on the second distillation will,
if submitted to a temperature of -20°, become in great part solid, deposit-
ing crystalline matter equal to at least half its bulk. By further rectification
both of the mother liquor of the solid portion (that is, of that portion of
the spirituous substance which is separated as fluid from the solid benzole
after refrigeration), and also of the rest of the distillate on this second rectifi-

page_text: cation, a further portion of spirituous substance may be obtained which will
solidify at -20°. I now expose the benzole which has been prepared for
refrigeration to a low temperature in a suitable vessel, and for the production
of this low temperature I use, if it be necessary, a freezing mixture. When
the benzole has been so congealed, I expose it to powerful pressure, and the
more powerful the pressure by which this separation is effected the purer will
be the result, and the lower the temperature at which the operation of pressure
is conducted the larger will be the produce. The fluid pressed out is set aside,
and after further rectification, if required, will yield another portion of solid
matter by refrigeration. The purification may be carried still further either by
again pressing at a temperature of 0° the mass obtained by a first pressure,
or by placing the mass in a funnel and allowing it to melt slowly in the air
with the bulb of a thermometer immersed in the mass, reserving as pure that
which remains solid when the temperature of the mass has risen to 0°. I call
the substance so produced absolute benzole; it will be found to boil constantly
at eighty or eighty-one degrees; it will produce a state of intoxication if
inhaled in the manner in which ether is used. It is an excellent substitute for
ether in many uses to which ether is applied, as for the solution of iodine,
quinine, wax, and fatty and volatile oils. The next spirituous substance or
tolnole, which when pure boils at about one hundred and ten degrees, and
which may be obtained in a state of partial purity by reserving the last portions
which come over in the rectification of benzole and the first which come over
in the rectification of camphole, is purified by treatment with acids in the
same manner as the benzole, but not by refrigeration. And I wish it to be
understood that by purified tolnole I do not mean a chemically pure hydrocarbon
having a fixed boiling point, but I mean an oily or spirituous substance obtained
from the coal naptha which will boil chiefly between one hundred and one
hundred and thirty degrees, being so much of the naptha as remains after
separating, on the one hand, as much as possible of the spirituous substances
that will yield a white flame with a current of air passed through them; and,
on the other hand, as much as possible of the oily substances which will not
take fire on the surface on the application of a lighted match, both being
understood of the fluids at the ordinary temperature of the air, since all that
applies to tolnole as regards its purification is also applicable to common
naptha and to other bituminous and empyreumatic oils, such as petroleum, or
native naptha, the oil distilled from bituminous schist, &c.
I will here state my method of purification as applied to coal naptha,
generally observing, however, that in the application of concentrated sulphuric
acid to common coal naptha a certain proportion of oil is lost by the

page_text: destruction of much of the cumole by the acid. I add to the naptha or tolnole,
separated as above described, concentrated sulphuric acid, in the proportion
of about three quarters of a pound and nitric acid or aquafortis in the
proportion of about a quarter of a pound to a gallon of the naptha or tolnole,
which has been previously carefully separated from water; I then agitate
them well together in a suitable leaden or other vessel. The nitric acid need
not be the strongest, that of specific gravity between 1.30 and 1.40 is suitable,
and it need not be pure; the crude acid, known as nitrous acid, for the acid
called single aquafortis, may be used. I do not confine myself exactly to the
proportions here given; or I use a mixture of nitric and hydrochloric acids,
or nitromuriatic acid, or nitrate of potash or of soda, instead of nitric acid,
in about the same proportions, with or without the addition of an equal
proportion of bichromate of potash, on bichromate of potash without the
nitrates; but if I use these salts instead of nitric acid I prefer to use a rather
larger proportion of sulphuric acid. Since the object is not to form definite
chemical compounds exact proportions are unnecessary; all that is requisite
is to have sufficient free sulphuric acid to dissolve the napthaline or a part
of the napthaline in the naptha, and not sufficient to dissolve. much of the
other hydrocarbons; to have sufficient free acid of any sort to dissolve all
the alkaline oils (aniline; picoline, &c.); and to have enough of the oxidising
agents; sulphuric, nitric, or chromic acids; to convert at once all the coloring
matter into new volatile products, and to have enough nitric acid to convert a
small quantity of the naptha into an aromatic oil, which leaves a slight
fragrance in the naptha when separated from it by subsequent distillation.
After thorough agitation and subsidence, I withdraw the naptha, and wash it
thoroughly with a large quantity of water till 'all the acid is removed. It is
advisable to separate the naptha carefully from the acid before adding the
water, otherwise certain compounds may be precipitated by the water from the
sulphuric acid liquor, which may impair the purity of the oils. I then either
agitate the naptha with a solution of caustic lime, caustic soda, or caustic
potash (preferring lime or soda to potash, as being cheaper, and then either
distil the oil with the alkaline fluid; or after removing it from the alkaline fluid,
in a still, to which fire is directly applied; or I rectify it by passing steam
through it, in the manner already known and in use; and when so distilling I
sometimes pass the vapour through a dry lime purifier, as hereafter described
when speaking of the purification of camphole; I then carefully separate the
naptha from water, and it is fit for use; or I sometimes allow it to stand after
agitation with chloride of calcium or chloride of linie in vessels in which a
small quantity of those substances have been placed, which removes the

page_text: remainder of the water. The tolnole or naptha so purified is applicable to
the making of varnishes, and to combustion in lamps, in which oil of turpentine
or coal naptha are usually burned; and also to burning in lamps when mixed
with alcoholic or pyroxylic spirit, as described in the third part of my Inven-
tion; or to napthalozing a current of heated air, so as to confer on it illu-
minating properties on being ignited. The camphole which is obtained by
the rectification of the last portions of the light oil and the first portions of the
heavy oil of coal tar is purified in: a different manner, since, firstly, it contains
a large quantity of creosote and other acid substances, and; secondly, a
considerable portion of the hydrocarbon which is required to be purified is
destroyed by, treatment with concentrated nitric or sulphuric acids; and the
method which I adopt to purify this oil is to digest it with a caustic alkaline
lye, and to distil it so that its vapour may pass over lime, and to agitate
it with hydrocholone acid; or with dilute nitric or sulphuric acids; and I
prefer to treat it first with alkali for this purpose. In a boiler or retort
with. two; apertures or necks, one of which is directly connected with the
upper condenser, herein-after mentioned, and the other with the condenser of
an ordinary still (which boiler I prefer to be of cast iron), I place the crude
camphole with about a quarter its bulk of a solution in water of caustic potash
or caustic soda; of specific gravity about 1.150, or with a similar quantity.of; a
solution of hydrate of lime in water, with an excess of fresh slaked lime, or
with dry caustic potash, or caustic soda, in the proportion of a quarter of a
pound of the alkali to a gallon of the oil, or with caustic lime in rather larger
proportions. (The carbonates of soda and potash may be used, but they do
not act so perfectly as the caustic alkalies or lime in the removal of the
acid substances and in the oxidation of the other impurities.) The boiler or
retort is surmounted with a vapour chamber or head, similar to that
recommended for the rectification of benzole, it being so.connected with one of
the necks of the retort that all the vapours condensed in it shall flow. freely
back into the retort. This head is kept surrounded with water as cold as possible.
As the object of it is to condense all the vapours and return them to the retort;
it may be connected by its other or upper opening with a still worm to
condense any vapours that may escape, or its other opening may be closed with
a loaded safety valve....
The oil.and caustic lye being placed in' the retort, the neck of the retort
which is directly connected with the still worm is closed, and that connected
with the upper chamber is opened; fire is applied, and. the aqueous solution.is
to be allowed to boil; the ebullition will continue for any length of time if the
condenser in the upper condenser be perfect, and even if a small quantity of

page_text: vapour be allowed to escape condensation the digestion will continue for a
sufficient length of time. I allow this digestion to continue for five or six
hours after ebullition has commenced ;. I then either lower the fire to stop
ebullition, and draw off the watery solution through a pipe at the bottom of the
boiler, and then close the neck connected with the upper condenser, and open
the other neck of the retort, which is directly connected with the still worm,
and then distil the oil over, or I change the outlet in the same way, and distil
without first drawing off the ley; in the latter case oil and water will come
over together at first, and the temperature in the retort will not rise far above
one hundred or one hundred and ten degrees, till nearly all the water and a
large quantity of the oil has come over; but if the water be drawn off, the tem-
perature in the retort will soon rise rapidly to one hundred and forty or one
hundred and fifty degrees before any fluid distils. I then sometimes set aside
the first portion that distils over, so long as samples taken in a small open
vessel catch fire on the surface on the application of a lighted match, and I
prefer to receive as camphole that which comes over subsequently, till the tem-
perature in the retort reaches one hundred and ninety degrees. The residue is
distilled over, distillation being stopped when the temperature in the retort
reaches about three hundred degrees, if it should rise so high before distillation
ceases, and is mixed with the dead oil in the same stage of purification, unless
this residual distillate contain much napthaline, in which case it will solidify
partially or entirely, and the solid part is rejected, and the fluid part only of
this residual distillate is added to the dead oil. The camphole after this distil-
lation is now agitated either with common hydrochloric acid or with dilute
sulphuric or nitric acid, formed by mixing the strong acids of commerce with
about six times their bulk of water; this agitation is continued for a conve-
nient length of time, and may be done in an open vessel with a stirrer; having
allowed the fluids to separate, I draw off the acid, and then I sometimes repeat
the agitation with a further quantity of dilute acid, with the addition of some
chloride of lime, in the proportion of a quarter of a pound of chloride of lime
to a gallon of the acid, but this may be omitted. The oil is drawn off and well
washed with water, from which it is separated and then rectified. It may be
rectified by passing steam through it, or by distilling from a retort to which
fire is directly applied, but in either case it is convenient to place between the
retort and the condenser a vessel, similar to the dry lime purifiers used for
purifying coal gas, in which lime is placed on plates or gratings in a chamber
having only two openings, so that the vapours pass over the lime; and I prefer
to have this lime purifier of such size that it may contain lime conveniently
spread, in the quantity of about half a pound of lime, more or less, to a gallon

page_text: of the oil placed in the retort, but a smaller vessel may be used. This vessel
is so arranged, that the vapour of the oil or water and oil as it leaves the
retort passes over the lime, which deprives it of any acid remaining in it, and
then, passing into the condenser, is reduced to the fluid form. But I prefer to
rectify it in a retort over fire directly applied, without the presence of water or
steam, and to use a thermometer inserted in the retort, and to cease receiving
as camphole when the temperature in the retort reaches one hundred and.
ninety degrees; by this means I obtain the oil colorless, and it should be of
specific gravity 890 or 900, or, if the distillation be not continued so far,
the specific gravity may be as low as 870. Concentrated sulphuric and nitric
acids, separately or mixed, may be used in the purification of camphole, but I
prefer not to use such acids, as a considerable loss of hydrocarbon is thereby
sustained, and the use of concentrated nitric acid sometimes confers a yellow
color on the oil, which it does not lose on rectification. I sometimes repeat.
this treatment with alkali and acid once or oftener. Camphole so purified is
applicable either alone, or mixed with the common naptha of commerce, or
mixed with some of the oils having lower boiling points separated in my pro-
cesses, or with the pyroxylic spirit for burning in lamps. It is also useful as
a substitute for oil of turpentine in making varnishes.
For the purification of the dead oil I adopt the same method of digesting
with an alkali as that which I have described for camphole, but I prefer to use.
a stronger ley and in larger proportion, and to continue the digestion for a longer
time before I change the outlet and commence distillation, since the dead oil.
contains a larger quantity of acid substances. The same description of appa-
ratus and the same sorts of alkali are applicable to the dead oil as to the
camphole; but caustic alkalies are much to be preferred to carbonates, and in
rectifying the dead oil from which the camphole has been previously separated
by distillation, which is that which I prefer to treat in this manner, though the
method is equally applicable to dead oil from which the camphole has not been
removed after digestion with the alkali; if the ley be not drawn off, very little
oil will be carried over with the water which distils off first, and whether the
ley be or be not drawn off, I prefer to receive separately all the oil which
comes over before the temperature in the retort reaches two hundred degrees,
and if there be little napthaline present I add this oil to the camphole of the
corresponding degree of purity. If there be much napthaline present I reject.
so much of that part of the distillate from the dead oil as solidifies in the cold,
which will be the case in some instances while the temperature is rising from
two hundred and ten degrees to two hundred and twenty degrees or even
higher, and the quantity which it will be convenient to reject may be ascer-

page_text: tained by observing whether a thin film of the distillate received on a cold
surface solidifies when the temperature in the retort is above two hundred and
ten degrees; when it ceases. to solidify on being so examined I commence to
receive the mortuole for purification. If none solidify on cooling I receive all
the distillate above two hundred degrees together, till the temperature in the
retort reaches two 'hundred and: eighty degrees or two hundred and ninety.
degrees; I reject what comes over above, as containing too much para-
napthaline, and instead of treating the oil with dilute acid, I treat the dead oil,
after distilling from the caustic ley. with oil of vitriol, in the proportion of one
pound of oil of vitriol. to one gallon of oil, and with or without the addition of
a small quantity of nitric acid; I agitate the acid with the oil in a suitable
vessel for one or two hours, and I prefer to allow the oil to stand with the acid
for two or three days;..and to repeat the agitation occasionally; I. then draw.
off the oil from the acid after having allowed it to settle; finally, I distil it
through a dry lime purifier, as described, for the purification of camphole. The
oil should be collected in this rectification between the temperatures of two.
hundred and twenty degrees and two hundred and eighty degrees. This oil
will be of a pale yellow, or almost colorless. I sometimes repeat this treatment-
of the mortuole with acids and alkali once or oftener.
:
It is convenient sometimes further to purify the mortuole, camphole, and other
oils and spirituous substances by filtering them through finely divided carbon,
for which purpose I prefer animal charcoal or lamp black which has been
digested for a short time in oil of vitriol; or boiled in a solution of carbonate of
potash, and then dried and heated to redness in a closed vessel recently before
use; and the filtration may be conveniently conducted by placing the oil in the
filtering apparatus over a vessel or receiver, into which the oil will be forced
through the filter by the pressure of the air when the air is exhausted from
the receiver. By further treatment with caustic, alkali, or lime, and with
sulphuric acid, and by subsequent rectification, the mortuole may be obtained
quite colorless. The oil so obtained is applicable to many of the purposes to
which oil of turpentine is applied, and also to many of the purposes to which
fixed oils are applicable; and it is applicable either alone or mixed with the
more-volatile hydrocarbons to burning in naptha vapour pressure lamps, and
when mixed with pyroxylic spirit in suitable proportions to burning in lamps
in which oil of turpentine or the fixed oils are burned.
What I here claim in respect to this second part of my Invention, is the
purification of the spirituous substances and oils which I manufacture from
coal tar by treatment with chemical agents according to principles laid down,
depending on the nature of the spirituous substance and oils aforesaid, and of

page_text: the impurities desired to be removed. I also claim the use of nitric or nitrous
acid, of nitromuriatic acid, and of chromic acid, and the salts of those acids,. in
the purification of empyreumatic and bituminous volatile oils, and the purifica-
tion of certain of the oils manufactured from coal tar by digestion with alkalies,
in the manner above described, and by distilling them, so that their vapor is
passed over. lime in the manner above, described, and the purification of. a
spirituous substance obtained from coal tar by congelation and pressure, which
substance so purified I call absolute.benzole.
. I now.come. to the third part of my Invention, videlicet, an improvement' in
the application of spirituous substances and oils to the purposes of artificial
light, which improvement consists in diminishing the proportion of carbon .in
the flame produced when such diminution is necessary: It is well known that
the volatile hydrocarbons, of coal tar and other similar substances when.burned
in the ordinary manner evolve so much smoke as to render them unfit for
general illumination owing to the large quantity of carbon in their composition,
and that to obtain a pure white flame from these substances.it is necessary to
lessen the proportion of carbon to oxygen which exists in the flame; this. I
accomplish by mixing the vapor of the spirituous substance' or oil which contains
much carbon with some other gas containing less or no carbon, such gas being
either a permanent gas, which being passed through the spirituous substances
takes up a quantity of their vapor, or such gas being the vapor of volatile:fluids
mixed with that of the oils or spirituous. substances. I am aware that this
method of reducing the proportion of carbon in the flame arising from volatile
hydrocarbons has been applied before, but with these differences; firstly, that
such spirituous substances as those which I apply, by means of mixing their
vapor with permanent gases, have not been hitherto applied in the manner in
which I apply them to the purposes of artificial light, videlicet, liquid substance's,
which are so volatile as to yield so much of their vapor to a current of common
atmospheric air as to enable the air to carry it through pipes to a distance from
the reservoir of liquid without the application of a high temperature to the liquid;
and, secondly, with this difference, that such spirituous substances as I apply,
by means of mixing their vapor with the vapor of spirits containing little carbon,
have not been hitherto mixed with such spirits in the manner in which I mix
them, videlicet, by simply mixing the hydrocarbons and spirits. without the
necessity of subsequently distilling the mixture, and, first, of. the: volatile.
spirituous substances and oils, which I burn by mixing their vapor with per-
manent gases. I will first repeat my statement, that sufficiently. volatile
hydrocarbons may be prepared from a variety of tars and bituminous matters,
both natural and artificial;, such as wood tar, turf tar, animal tar, bituminous.

page_text: schist, native naptha of Persia, Amiano, Rangoon, and other places, india-
rubber resin, and generally from the tar obtained by the destructive distillation
of organic matters, and that such volatile hydrocarbons may be prepared by
rectifying the most volatile oily part of such tarry and bituminous matters,
especially by rectifying. the volatile oils in the manner which I have described
in treating of the rectification of coal tar benzole, and reserving such portions
as pass over at the lowest temperatures, that is to say, such as boil below and
a little above one hundred degrees; and such spirituous substances are appli-
cable in the same manner as the spirituous oils of coal tar to the method which
I have invented; but I prefer to use the spirituous substances' which I manu-
facture from coal tar, because they usually contain: the largest amount of carbon,
and therefore yield the whitest light when burned in the manner which I am
about to describe, and because coal tar is the most abundant bituminous
substance in this country, and yields a large proportion of these spirituous
substances; and I prefer to use the crude benzole which has been treated
with dilute acid in the manner described in the second part of my Invention,'
but which has not been treated with concentrated sulphuric acid, and I prefer
wlien preparing the benzole for this purpose to set aside the first' fraction of
distillate, equal to about one-eighth of the benzole expected, videlicet, the crude
alliole, which being so extremely volatile would cause the first portion of air
passed; through the receiver to be far more luminiferous than the subsequent
portions; and because the crude benzole will not be of uniform volatility, but
will contain a certain portion of less volatile oil, part of which will remain
behind, so that the last portions of air will be less luminous. I prefer to add
the 'alliole so separated in the distillation to the fluid subjected to the air current
when its luminiferous properties shall appear to have fallen off, that is to say,'
when there shall be a perceptible diminution of the intensity of the light yielded
at the burners, or an increase in the quantity of blue color in the flame, such
addition of the very volatile spirituous substances to the less volatile residue
forming a mixture of the required volatility; or I mix some of the volatile
hydrocarbons above described and indicated, as suitable for this purpose," with
such alcoholic or pyroxylic spirit or other volatile spirits or others as will mix
with them, with or without distilling such spirits or ethers with the hydro-
carbons, and I apply these mixed spirituous substances to the purposes of light,
in the same manner as the volatile hydrocarbons alone, videlicet, by passing
through or over the mixture à current of air, according to the method liereafter
described. It is not in all cases necessary to use hydrocarbons in this manner
when such of the other ingredients herein mentioned, videlicet, spirits and
others, are used as contain sufficient carbon to yield a luminous flame when

page_text: applied in this manner, such as sulphuric ether and acetone, otherwise called
pyroacetic spirit. But I prefer the use of the volatile hydrocarbons in all cases,
because all such mixtures or spirits alone will yield to the current of air a less
luminiferous vapour than that of the hydrocarbons.
And next, of the manner in which I mix the vapour of such hydrocarbons
or spirituous substances with permanent gases or airs for the purposes above
mentioned. I supply a convenient quantity of such spirituous substances to
a vessel with two or more apertures, through one of which apertures a current
of air or gas may enter the vessel, and through the other may leave it, charged
with the vapour. And the said vessel may be either a simple vessel with only
two apertures, such as a two-necked bottle, or it may be a vessel with a third
aperture, by which it is connected with a second closed vessel, by means of
which a constant fluid level is maintained in the first vessel; or the vessel may
have one or more additional apertures, through which the fluid is allowed to
trickle slowly or fall in a constant shower into the said vessel from a reservoir
above, and the said vessel, videlicet, that through which the air passes may or
may not be supplied with pieces of sponge, or cotton, or other absorbent
material, which may receive the fluid either as it trickles from above or by
absorption from below; and if the vessel be supplied constantly by fluid
trickling or falling into it, there should be another aperture for the escape of
the fluid into a third vessel, when the fluid arrives at a certain convenient
level in the first or evaporating vessel. And of the two apertures for the
passage of the gas or air, one opens only into a tube, which does not extend
into the said vessel, though the other aperture, videlicet, that through which
the air enters a tube, passes; and it may be made to pass through an air-tight
stuffing, so that the distance to which it descends in the vessel may be adjusted
at pleasure by sliding it up or down, and it may be made to terminate
within the vessel at its lower extremity either in a simple aperture of the
same size as the bore of the tube, or it may be made to terminate in a rose,
with a number of small apertures, and such its lower extremity may be made
to dip below the surface of the fluid in the reservoir; or it may be so adjusted
that the air flowing from it may play upon the surface of the fluid; or it may
be above the surface of the fluid, and surrounded with sponges, cotton, or other
absorbent materials, as above mentioned, so that the air passing over the
sponges may become charged with the vapour of the fluid contained in them.
The tube attached to the other aperture leads to the burner, at which the gas
or air charged with vapour, which I shall call vaporized air, is burned; and
I supply the gas or air to the reservoir by any of the known methods of
obtaining a continuous pressure or current of air.

page_text: I claim nothing, original in the mode of, supplying the air; all that I here
claim is, the passing of a current of gas or air, however produced, into a vessel
in, which it shall become charged with the vapour of a spirituous substance,
such as may confer on it the property, of burning with. a luminous, flame, 'at a
burner which may be distant from the reservoir in which the spirituous sub-
stance is contained, without the application of a, high temperature' to the
reservoir. And I do not confine myself; to, the use of any particular gas or
air, since almost any permanent air which is not of a poisonous or corrosive
nature will answer equally well, except pure or nearly pure oxygen, which
forms a violently explosive..mixture with. the vapour, which it takes, upI
may mention' as applicable the following, videlicet, hydrogen, carbonic acid;
carbonic oxide, or the common inflammable gases, or a mixture of these with
common air, but I prefer to use such mixtures, as are not explosive; themselves,
and will not become explosive when. charged with the vapour of, the hydro-
carbon and the mixed! gases obtained by passing steam over heated carbon;
and I may remark, that I am aware that it has before. been proposed to pass
illuminating gases over volatile hydrocarbons. for the purpose of increasing
their illuminating power, and also to pass combustible gases which do not
burn with a luminous flame over similar matters for the purpose of confering
illuminating power upon them; but I shall state below to what this part. of
my Invention is limited, so that I do not claim any such application as may
have been already known and in use. And I apply this method of illumination
either on a small scale, in which the whole apparatus, that is, the source of the
current of gas or air, the reservoir of the fluid, the tubes attached to the
reservoir, and the burner or burners, are included in one system, which may
be compact and portable; or I apply it on a larger scale, in which pipes are
laid down in a manner similarly to that already in use for the distribution of
illuminating gas.
I will now state the most favourable conditions for insuring a supply of air
charged with the vapour on a scale suited to the illumination of buildings.
I will suppose the air or gas to be supplied from a central source, as above:
suggested, in a sufficient quantity to supply all the pipes which are distributed:
to the burners in different parts of the buildings, such supply of air, if atmo-
spheric air be supplied through the system, being generally larger than the
ordinary supply of coal gas necessary for producing the same amount of light.
In a convenient part of the building, which should not be cold, .or: subject to
great variations in temperature, I place the reservoir or reservoirs, as above
recommended, where the air so supplied is charged with the vapours of the
volatile substance by the means above. described...From the reservoir .or

page_text: reservoirs I lead pipes over the building to the burners, in like manner to that
which is practised with coal gas, the pipes being. of size suitable to supply the
burners attached to them. It is evident, that the fluid in the reservoir must
be very volatile, for if not the air will not take up sufficient vapour, or will
deposit it in the pipes. And here I may state that the ordinary coal naptha
of commerce is not sufficiently volatile for the purpose. The most volatile
that is sold will yield a partially white flame when so treated, especially when
first submitted to the current of air; but as evaporation proceeds, the flame,
will become too blue to be very useful, so that the flame will only. remain
luminous during the consumption of a fraction of the quantity.in the reservoir,
after which it will cease to be luminous; because all the' volatile substance or
benzole will have been removed; and this will be the case with common coal
naptha, however often it may have been distilled, unless the volatile parts be
reserved separately, according to the principles which I have' described, because:
repeated distillation alone does not at all increase the volatility of the naptha,
unless on distillation the less volatile part be rejected. If spirituous sub-
stances, such as I have above described (especially the hydrocarbons, manufac-
tured from coal tar), and which boil at a temperature below or but little above
one hundred degrees, be used, and the reservoir be kept in a moderately warm.
place, that is, where the temperature is not much below the average tempera-
ture of our climate, the air will take up sufficient vapour to burn in the'
manner required. But because when the air continues to take up vapour,
from the spirituous substance the fluid will become gradually cooled by its own
evaporation, so as to become colder than the ordinary temperature of the air,
and will therefore gradually give off less and less vapour, unless the vapour.be
prevented from absorbing from the fluid more caloric than is supplied to the
fluid; it is therefore necessary, for the maintenance of a uniformly lumini-
ferous gas or air, to prevent the fluid from being so cooled, and this may be
done in various ways, either by using so large a quantity of fluid in the
reservoir that it will not be much, cooled during any one period that it is in
use, or by passing the air current alternately through or two or more reservoirs
as they become cooled in succession, or by slightly warming the reservoir or
the air tube as it enters the reservoir, which may conveniently be done by
a small burner near the reservoir, or by continually changing the fluid by a
stream of fluid trickling through the reservoir, so as to remove the cooled
fluid, and to supply fresh spirituous substance not cooler than the temperature
of the air.
**
And here it may be remarked, that it is better that the pipes which conduct
the air, especially those through which it passes after being vaporized, should

page_text: be exposed as little as possible to cold, and I prefer, where it is possible, to lay
the air pipes along the course of flues or pipes through which warm air or
water is passing, and always to select the warmest places where that can be
conveniently done; and it is convenient sometimes in very cold weather
to pass the pipe which conveys the air to the evaporating vessel or reservoir
through a water boiler, or other place suitable for warming or slightly heating
the air in its passage, but this is not absolutely necessary; and if the air be
too much heated, it will take up too much of the vapour of the spirituous
substance if a very volatile fluid be used, which will be partially deposited
again as fluid in the pipes, or will cause the flame in the burner to smoke.
It is evident that there may be any number of reservoirs, and that each
reservoir may supply any number of burners, or each burner may have its
own reservoir, which may be close to or distant from the burner. In the same
manner streets and other out-door places may be lighted; but in these cases,
since the pipes are more exposed to cold, it is convenient to place the reservoir
of fluid within the lantern in such position that without being heated it may
be kept slightly warm by the heat of the flame, or in some other neighbouring
place where it may be protected from the cold. A less volatile substance than
benzole may be applied, such as the tolnole, which I obtain from coal naptha,
which may be received on distillation between one hundred degrees and one
hundred and twenty degrees; but this substance at ordinary temperatures will
only yield sufficient vapour to atmospheric air passed through it to yield a blue
flame, so that if this substance be used be with a current of atmospheric air, it
is necessary to keep the reservoir hotter than the ordinary temperature of the
air, and the hotter it is the more vapour will the air take up; and it is in this
case convenient to heat the air before passing to the reservoir, and to keep the
pipe, after leaving it as warm as possible, as well as to have the burners as
near as possible to the reservoir, but it is not necessary that flame should
be applied to the reservoir to maintain evaporation. In cases where this
adaptation is necessary I claim no originality.
What I claim, in respect to the third part of my Invention, is, the appli-
cation of hydrocarbons and of volatile spirituous substances to the purposes.
of artificial light, by appropriate mixture with their vapour of other gases or
vapours, videlicet, firstly, by mixture, in the manner above described, of a
current of atmospheric air or of other non-inflammable gases with the vapour
of spirituous substances which are so volatile and of such nature, that a
current of such air or gases, of the ordinary temperature or slightly heated,
having been passed through a reservoir containing the spirituous substances,
may burn with a luminous flame at a distance from the reservoir without the

page_text: .
application of heat directly to the reservoir, or by mixture, in the manner herein
described, of a current of inflammable gas or gases with the vapour of such
spirituous substances as have not before been so applied, videlicet, such volatile
hydrocarbons as are manufactured according to the principles of the first part
of my Invention, so that I may be understood as not claiming any Invention
in which luminiferous gases are passed through such volatile hydrocarbons as
are already in use for the purpose of increasing their illuminating power, or
in which the non-luminiferous inflammable gases, such as carbonic oxide,
hydrogen, or the gases produced by passing steam over highly heated carbon.
are rendered luminiferous, by charging them with the vapor of any such
volatile coal naptha as may have been already known and in use, or in which
gas or atmospheric air is passed through or over such volatile hydrocarbons
for the purpose of producing a luminous flame, wherein such hydrocarbons
are used as require either that a high temperature should be applied to the
reservoir to promote evaporation, or that the burner should be close to. the
reservoir containing the hydrocarbons. And, secondly, by mixture of the vapour
of spirits with the vapour of hydrocarbons, in the manner which I shall
describe below. If the apparatus for illumination be required on a small
scale, so that. the reservoir, the pipes, the burner, and the source of air are
comprised in one system, which may be portable, and adapted in form, to a
table lamp or other lamp, the method is applicable in the same manner as
on the large scale, a stream of air being supplied through the pipes by any
convenient means. But a method of producing the current of vaporized
atmospheric air is applicable on a small scale which is not so easy of appli-
cation in a larger apparatus, where the length of the pipes opposes greater
friction to the passage of the air, and since, so far as I am aware, this method
of leading a current of air to a flame through pipes and a reservoir, and so as
to be the means of taking up volatile matters, videlicet, by the draught
caused by the flame itself is not already in use, and requires particular adjust-
ment, I will explain the method and what is necessary to be attended to in
its application, and will illustrate the application by a Drawing. The apparatus
consists of a reservoir or evaporating vessel, supplied, as above described, with
two pipes, one of which leads from the top of the vessel up to the burner or
burners, and the other descends into the vessel, and terminates in a wide
opening a little distance above the surface of the fluid in the vessel; this tube
should be of larger calibre than is necessary to supply air when forced through
it by pressure, so as to offer as little resistance as possible to the passage of
the air, and should terminate in a wide opening on the exterior of the
reservoir. The upper part of the vessel above the fluid level should be

page_text: 'capacious, and should contain a sufficient quantity of cotton wicks, supported
on a frame and dipping by their lower extremities into the fluid or of other
porous material, to offer a large surface for the evaporation of the volatile
spirituous substance in the vessel, yet not sufficient to obstruct the free
circulation of air through the vessel. The pipe which leads to the burner
should be capacious, and as little tortuous as may be convenient, so as to
allow free passage to the air. There should be, a third small pipe opening
into the reservoir, or into that part of the pipe through which air enters the
reservoir, which is outside the reservoir, and this third pipe may be fitted with
a mouth-piece, or a small bag or bellows, for the purpose of forcing a,current
of air through the vessel for a few seconds when it is intended to kindle the
flame. The burner must be provided with a chimney, which must be of
sufficient length to cause a good draught by the ascent of the heated air from
the flame. The opening or openings through which air is admitted to the
chimney outside the burner should be much smaller than is usual in lamps,
and it is convenient to have a moveable ventilator, so as to regulate the supply
of air to the chimney. It will be understood that if the spirituous substance
in the reservoir be very volatile, a considerable fraction, but yet not the whole
of the air necessary to support combustion, will be supplied to the burner
through the reservoir as the vehicle of the fuel, and that but little and yet a
certain quantity of additional air is necessary to be supplied outside. the
burner to complete the combustion. It will be understood also, that because
the object of the arrangement is to compel a sufficient quantity of air, by
means of the draught of the chimney, to pass through the pipes leading to
and from the evaporating vessel, and because the air will not pass through the
pipes if it can arrive at the chimney by a channel which offers less resistance
to it, therefore no more air must be allowed to pass into the chimney outside
the burner than is requisite to complete the combustion of the vapour carried
up. by the current of air from the evaporating vessel. To light a burner in
a system supplied with air by this method, it is requisite to blow. a. current
of air through the pipe attached to the reservoir for this especial purpose,
closing, if 'necessary, for the time the aperture of the larger air pipe, then
to ignite the vapour at the burner, and before the stream of forced air is
discontinued, to place the chimney in its seat, and to maintain the flame by
a gentle stream of forced air for a few seconds till the chimney has become
sufficiently warm to maintain the draught. The apertures of jets at the
burners should be sufficiently large to allow a free passage to the vaporised
air; and I prefer to use burners with adjustable apertures, constructed on
the principle described in the fifth part of my Invention. The burners

page_text: may be of any convenient number in one system, and supplied by one
reservoir, and they may either be simple jets, or constructed on the Argand
principle, with a passage for air to the middle of the flame:**
.I
5.4
I proceed to describe the Drawing annexed, which represents such a system
for mixing air with the vapour of spirituous substances with a single Argand
burner attached. Figure A represents the parts of such a system. A is the
reservoir; B, the burner, each with their accompaniments; and Figure B
shows a sectional plan of the parts surrounding the 'burner. a is the tube,
with a mouth-piece, through which air is blown on starting the flame; b, the
tube 'through which air is supplied to the evaporating vessel during the com-
bustion; c, the tube by which the vaporised air is conducted to the burner.
It is represented here as being at its lower part a segment of a double cylinder,
so as to leave one side open for the approach of the hand, and of air to g and f,
and above as an entire double cylinder; which forms part of the burner; d, the
cotton wicks, suspended on a wire frame, which may be attached to b, their
lower extremities dipping into e, the fluid, and enveloping the mouth of b;
f, the channel for the admission of additional air to the centre of the flame;
g, the adjustable ventilator, for regulating the admission of air to the centre of
the flame; h, the adjustable ventilator for i, the passage for additional air to
the exterior of the flame. These ventilators are represented as being made
of two similar plates, lying one above the other in close contact, one of them
being fixed, and the other moveable by the thumb-pieces o, o', the plates being
constructed in áltérnate segments of close metal and of wire gauze, so that,
according to the position of the moveable plate, a greater or less amount of the
perforated spaces may be available for the transmission of air; by an obvious
adjustment both the exterior and interior channels for additional air may be
connected with a single ventilator. k, the inner wall of the outer air passage,
which is represented as also forming the external moveable wall of the burner,
by which the size of the annular jet or aperture n may be adjusted. It is
obvious that p; the inner wall of the burner, may be made adjustable for
the same purpose. 1, the chimney holder, which slides upon q, the outer wall
of the outer air passage, so' that by raising the chimney its available length
for the draught of air may be increased; m, 'the chimney, which should be of
sufficient length to cause a good draught when filled with 'heated air, and
should not be of greater diameter than is sufficient to afford free passage to
the air which passes through c, f, and i. "Next, as to the application of the
hydrocarbons to illumination, by mixing with their vapour the vapour of
'spirits containing less carbon, such as various others, and alcoholic spirit,
pyroxylic spirit, called 'also wood' spirit, or wood" naptha; and pyroacetic spirit,

page_text: called also acetone. The vapours of the hydrocarbons may be mixed with the
vapour of the spirits by heating the hydrocarbons, and spirits separately and
mixing the vapours after their evolution; but I prefer to obtain the requisite
mixture of vapours or gases by previously mixing the hydrocarbons with the
spirits, and by then evolving the vapour from the mixtures by the application
of heat, as may be done conveniently at the burners of the lamps in which the
mixtures are consumed. I am aware that volatile oils and spirits have been
mixed before for the purposes of illumination, but with these differences, either
that the mixtures have been such that it has been necessary to distil them for
the production of the requisite uniform fluid, or that they have been such that
when kept they have not remained uniform, and have therefore not been
applicable to the purposes to which I apply the mixtures which I prepare,
but neither of these circumstances attends my method, which I shall describe
below; I will first state the nature of the spirits which I prefer to use.. I
mean by acetone the spirit which is produced by the dry distillation of certain
of the salts of acetic acid, in the manner well known to chemists. When pure
it has no acid properties; it mixes with water in all proportions, and burns with
a flame partly white and partly blue. If acetone burns with a perfectly white
flame, it may be considered to be already mixed with some hydrocarbon, of
which it is not necessary for my purpose that the acetone should be deprived.
Its specific gravity may be raised either by the presence of water or of hydro-
carbon. The proportions which I give below must be understood as referring
to acetone of specific gravity not greater than 825, and containing little or no
hydrocarbon. Because acetone contains a larger proportion of carbon than
alcoholic or pyroxylic spirits, the proportions in which I mix it with the hydro-
carbons will be different from the proportions required for the other spirits,
and will be stated accordingly. If alcoholic or pyroxylic spirit be used, the
specific gravity should not be greater than 840, though it may be a little
greater without materially impairing its power of mixing with the oils. And
here it is desirable to state, that though for alcohol, or spirit of wine, specific
gravity may be a test of its suitability for my purpose, yet that is not absolutely
the case with the pyroxylic spirit of commerce. It is necessary for my.
purpose that the spirits should be as free from water as they can be obtained
consistently with cheapness, because the less water the spirits contain the
more of the hydrocarbons will they dissolve. The specific gravity of alcoholic
spirit indicates generally the quantity of water in solution in the spirit,
since water is generally the only foreign body which is mixed with it, so
as to raise its specific gravity. But in wood spirit either water or the
hydrocarbons of the wood tar may be present, either of which may increase

page_text: the specific gravity of the spirit. The presence of too much water unfits the
spirit for my purposes, but the presences of the oils of tar does not, so that
specific gravity alone is not a test of the fitness of the spirit. If a larger
quantity of hydrocarbon than the greatest, which I have stated below, be.
used in making a mixture, the tendency to produce smoke will be incon-.
veniently increased; and if a smaller quantity than the lowest which I have
mentioned be used, the flame obtained from the mixture will be below its
maximum of brilliancy, and will be more or less inclined to blue, and below
this point the diminution of brilliancy will increase with the quantity of spirit
employed; but with acetone, even if no. hydrocarbon be employed, the flame.
will still be luminous, which is not the case with alcoholic or pyroxylic spirits;
and since in this country at present ethers and alcohol bear too high a price to.
allow them to become generally applicable for my purpose, I prefer to use.
either wood spirit or acetone, and the remarks which follow apply to wood.
spirit and to acetone. I prefer to use the spirits colourless, or nearly colour-.
less, and such pyroxylic spirit as is of specific gravity not greater than '840,.
and becomes milky on the addition of water from the separation of a greater
or less quantity of hydrocarbon or acetone, of specific gravity not greater than
825, which is miscible with water without becoming milky. If, on experiment,.
the spirits are found to contain too much water to permit the solution of a
sufficient quantity of hydrocarbon, they may be sufficiently freed from water
by treatment with lime, as is well known to chemists; by which means also
they may be purified from acetic acid, which sometimes accompanies more or
less pyroxylic and pyroacetic spirits, and this purification from acetic acid is
necessary to prevent the fluid from corroding the metallic parts of the burners
and lamps in which it may be consumed. Such spirits will readily dissolve a
sufficient quantity of such hydrocarbons, as I shall mention below, by simple
mixture, without the aid of distillation or of heat.. I make all the mixtures
here mentioned by pouring the two substances together into a suitable vessel
and shaking them together. All the proportions stated refer to measured bulk
of the fluids. For a mixture which will burn with a brilliant flame without
smoke, if the flame be protected from draughts of air I add one part of the
hydrocarbon to two parts of wood spirit; or to four parts of acetone, such
mixtures are well suited to burning in " vapour lamps," by which I mean
lamps in which the fluid supplied to the burner is converted into vapour by
the heat communicated from the flame to a cap which covers the wick; or for
burning in lamps in which a volatile oil or spirit is consumed, and in which
the wick is exposed to the flame without any particular adjustment, for the
admission of a large quantity of air to the flame, but in either case the flame

page_text: being protected from currents; of air,by a chimney or otherwise, and a.mix-
ture which contains a larger proportion of hydrocarbon and a less quantity. of
spirit; as, for instance, equal parts of hydrocarbon and of pyroxylic spirit, or
one part of hydrocarbon: to three parts of acetone, is a fluid suited to burning
in such lamps where smoke is not objectionable; or for burning in lamps in
which an excess of air is supplied to the flame, and a mixture which contains
a smaller proportion of hydrocarbon and a larger proportion of spirit, as, for
instance, twenty-four parts. of hydrocarbon with seventy-six parts of pyroxylic
spirit, or fifteen of hydrocarbon with eighty-five of acetone, is a fluid suited to
burning in such..lamps without the protection of a chimney, and without the
supply of an excess of air to the; flame. And for these purposes I.use .such
hydrocarbons as will dissolve in the spirit without being distilled with it, and
which, when dissolved, will, not separate from the solution when the mixture
is preserved with the precautions stated below, such as the oil of wood tar, or
the oil of coal tar, or oil of..turpentine mixed in small quantities. with oil of
coal tar; and if oil of turpentine be,used with pyroxylic spirit, the addition of
oil of coal tar is desirable; because pure oil: of turpentine. alone is not easily
soluble in alcoholic or in wood spirits, in the manner I have above indicated;
but a sufficient quantity of oil. of turpentine may be, dissolved in acetone, to
yield a good. flame without the addition, of oil of coal tar; and for combustion
in vapour 'lamps, I prefer to use the best rectified coal naptha, and especially
the most volatile spirituous, substances, which I prepare from.coal naptha; and
I may remark; that the more volatile hydrocarbons are more soluble in pyroxylic
spirit than the less volatile oils manufactured from light oil, so that a larger
proportion 'of. benzole than of common rectified naptha may. be mixed with
the-spirit, and the more volatile the hydrocarbon the more suited is it to
burning in, the vapour-lamps; firstly, because of the lower temperature required
to volatilize it; and, secondly, because the more nearly similar volatility of the
hydrocarbon with that of the spirit will cause the mixture to be less liable to
alteration by evaporation, either from the lamp or from the stock in- hand,
so that if evaporation takes place a residue will be left more nearly similar
to the original mixture than if a less volatile hydrocarbon be employed, which;
if the spirit should evaporate, will be left behind in excess in the mixture, and
might cause the flame to smoke; but it is requisite to guard against evaporation
in keeping the mixture, since the tendency of evaporation will always be to
decrease the quantity of spirit, and therefore to increase the quantity of hydro-
carbon in the mixture, because, the spirits are more volatile than the most
volatile hydrocarbon which is likely to be used in the mixture. I also mix
camphole, prepared as above described, with the spirits, and this mixture may

page_text: be burned in vapour lamps, though it is not so well suited to such lamps as the
mixture containing the more volatile hydrocarbons. I also mix with spirits
the heavy or dead oil of coal tar (preferring that it should be rectified and
mixed in the proportions above stated. This forms a good oil for burning in
common lamps of the Argand construction, or in lamps with a simple wick, as
a substitute for the fixed oils-usually burned in such lamps.. And if the heavy
oil of coal tar, or the less volatile portions of the light oil, such as the cam-
phole, be mixed with an equal measure of spirit, the mixture so produced. is
suited for burning in lamps in which a large supply of air is directed to the
flame; and care should be taken before making all such mixtures to deprive
the hydrocarbons of the small quantity of water which they may hold in
suspension by agitation with lime, or with chloride of calcium, or by, distilling
them over lime or chloride of calcium, or allowing them to stand in vessels
containing lime, or chloride of calcium, or common salt, or other substances
having like affinity for water. I have before stated that it is necessary to
deprive the spirit of water as much as possible, and care must be taken. when
making the mixture, as well as in keeping such mixture when made, to exclude
all water from the mixture; and for this purpose, as well as to prevent evapo-
ration, it is desirable to keep the mixture, in a vessel carefully closed or
stoppered, so as to prevent the absorption of moisture from the air, since the
addition of a certain quantity of water. to the mixture may separate the oil
from the spirit, with which the water will combine. I do not confine myself to
the use of the proportions which I have stated above for the mixture of hydro-
carbons. and spirits, and it must not be understood that I state such propor-
tions as being absolutely the best in all cases, since some samples of spirits
differ from others in the amount of luminiferous matter: which they, contain,
without much corresponding difference in specific gravity; but in all cases a
mixture may be made of any quality, that is, so as to yield a flame containing
any: amount of carbon that may be required, and this may be done by pouring
given small quantity of the spirit into a graduated measuring vessel, then
adding by degrees the hydrocarbon from another graduated vessel. The
mixture may be tested by moistening the wick' of a lamp of the sort which is
intended to be used with the mixture, by lighting the lamp, and observing the
flame when the proper degree of luminosity is attained; the proportions of the
mixture may be known by observing how much hydrocarbon has been mixed
with the quantity of spirit taken, allowing for the quantity of the mixture
which has been absorbed by the wicks on each trial, and it is better to use a
fresh wick for each trial of the mixture. The required quantity of the mixture
may then be made in corresponding proportions from the spirit and hydro-
a

page_text: carbon. If at any time the quality of the mixture has deteriorated by the
evaporation of the spirit, it may always be restored by the addition of a proper
I have
quantity of spirit, which may be ascertained in the same manner.
found that the proportion of air directed upon the burner being the same, the
smaller the apertures from which the vapour escapes at the burner, or
the smaller the surfaces of wick exposed to the flame, the larger may be the
proportion of hydrocarbon in the mixture, and that the apertures for vapour or
the exposed surface of wick being the same, the greater the quantity of air
directed to the flame in the manner most favorable to perfect combustion, the
larger may be the proportion of hydrocarbon in the mixture.
What I here claim is, the mixture of hydrocarbons or volatile oils and
spirituous substances with such spirits as will dissolve them or mix with
them (without being distilled with them), and when mixed will retain them
in solution in proportions suitable to burning in lamps for the purpose of
artificial light.
I now come to the fourth part of my Invention, videlicet, to the improvement
in lamps, which consists in an improved construction of lamps applicable to the
combustion of volatile oils and spirits, mixed as above described in the third
part of my Invention; the improvement being the formation and adaptation
to lamps of a burner which yields a film of flame, the thickness of which may
or may not be made adjustable by the movement of one more parts of the
burner, which parts may or may not be made to be moveable, such burner
being so constructed as to convey heat to the fluid applied to it so as to
convert it into vapour, which is burned as it escapes from the jet or slit in the
burner.
And for the better understanding of this part of my Invention, I annex
Drawings, to which reference is made by the letters in the description given
below; and here I will state that I do not confine myself to the exact form
of the burners, since they may be made of other forms in horizontal section,
such as oval, square, or triangular, in which case the moveable part of the
burner is to slide vertically on the immoveable part. And their form in
vertical section may be modified in various ways, either in the proportions
of breadth to height, or in the outline of the various parts; and the edges
of the cones, cylinders, or pieces which form the slit may be notched or
serrated, so as to form a series of single jets or ribs in the flame;
I prefer that the burner should be circular in horizontal section,, both for
appearance, and because, if a part be moveable, it will admit of being adjusted
by a screwing motion, which, whether a screw be cut on the surface or not,
admits more easily of precision in the adjustment; and I prefer that the edges
but

page_text: of the cones or cylinders be linear and not serrated, and either the inner or the
outer wall of the vapour chamber may be made moveable in the same manner,
but I prefer to make the outer wall moveable, as being the most convenient for
adjustment in practice.
What I claim is, the formation of a burner with a slit jet, the breadth of
which may or may not be adjustable by a moveable part, such burner being so
connected with a lamp that a part of the mixed volatile oils and spirits
supplied as fuel in the lamp may be converted into vapour by the heat evolved
by the combustion of a previous part of the same fuel, and that the vapour
may be conveyed to the burner and then consumed, according to the principles
exhibited in the annexed Drawings. The fluid may be supplied to that part
of each burner at which it is volatilized, either by a wick suited to the form of
each burner, which wick may be of cotton or other suitable material; or the
fluid may be supplied by pressure at a constant level in the same part of the
burner, in which case the part to which the fluid so rises in the burner should
be a tube, with a narrow bore or chamber, of small thickness, so as to expose
only a small quantity of fluid to heat at once, and the size of this tube or
chamber will vary, according to the size of the burner, and should be about half
the breadth of the thickness of wick suitable to the same size of burner; and
if a wick be used to conduct the fluid up to the burner from a level below, I
attach to the lower part of the wick holder a hollow cone or tube, which
envelopes the wick and dips below into the fluid, so that the wick is in a closed
chamber, from which the only escape is the burner jet. The object of this
part of my Invention is to prevent evaporation from that part of the surface of
the wick which is above the fluid in the reservoir and below the burner. This
cone may be of glass, and if made of metal it is better that it should be of a
metal of low heat-conducting power, or that a ring of non-conducting material
should be inserted between it and the wick holder, to prevent the communica-
tion of heat direct to the fluid in the reservoir; and this tube or cone may have
one or more holes in it, so as to give a communication with the upper part of
the reservoir without allowing much vapour to escape from the wick; and. I
may remark, that the thinner the metal of which the burner be made the more
easily will the flame be lighted, and the more liable will it be to be extinguished
by contact of cold substances with the metal of the burner, and the more liable
will it be to variation from the effect of currents of cool air; and if the metal
be thick, it will be less easily lighted, and less liable to be extinguished or
rendered unsteady by currents of cold air, though it will be more likely to
evolve smell when extinguished; and if the metal be thick, it sometimes will
be convenient to attach to the lower part of the burner a small cup, in which

page_text: some spirit may be ignited, which will heat the burner and cause the evolution
of vapour; or the burner may be sufficiently heated to enable it to maintain
the evolution of vapour by removing the moveable cone or cap and igniting
the wick, and by then holding the cone or cap in the flame till it is become hot,
then replacing it and again applying a light, if necessary, to the orifice of the
burner; or the burner may be heated by means of a small lamp, or by any of
the other methods already in use for lighting lamps, in which combustion is
maintained in the same manner.
I do not confine myself to the use of any particular metal in the con-
struction of these lamps, or parts of lamps, but I particularly recommend
silver or brass; and it is especially convenient to form those parts of the
burner which are the most exposed to the heat, of silver and sometimes of
platinum; and these lamps may be constructed with or without chimneys
and appliances for directing an increased supply of air to the flame; and
it should be remembered, that in proportion as such appliances are used, a
greater proportion of hydrocarbon may be used in the fluid supplied to the
lamp. Figures 11' and 16 shew lamps for burning such volatile oils and spirits
or mixed oils and spirits as are suitable for burning in lamps in which they
are volatilized by the heat produced in the burner; Figure 11 is one in which
a twisted wick is used; Figure 16 is one in which a hollow cylindrical wick
is used; both Figures are in section. In Figure 11, a is the cone or inverted
vessel which covers the lower part of the wick, so as to prevent evaporation
from that part of the wick which is above the level of the fluid in the reser-
voir. Figures 12, 13, 14, and 15 are burners for consuming the same volatile
oils or spirits, and suitable for such a lamp as that in Figure 11. The same
letters show corresponding parts in each of these; and in Figure 11, b is the
wick, which may be of twisted cotton or other absorbent material; c, a
moveable cone or cylinder, by moving which the size of the slit or orifice d
may be adjusted; e, passage or passages by which air is admitted to the centre
of the flame; f, part which being heated by the flame conveys heat to the
wick, and causes the evolution of vapour; which in Figure 11 is a hollow
button or cap surrounding the top of the wick; in Figure 13 a solid button,
through which and through a tight collar in the top of the wick holder a rod
or wire may be made to pass so as to reach the wick g, may be raised or
depressed by means of a wire attached to it, or by a pinion and rack work,
which are not shewn in the Drawing, so as to decrease or increase the amount
of contact with the wick. In Figure 14, f is a solid button attached to a pin
which passes through a cross piece and touches the wick; and in Figure 15, f
is a cap, which with the rest of the burner is moveable upon the wick holder,

page_text: on which it slides by means of the collar' h; .k, a chamber from which, and
tubes through which; the vapour is conducted from the wick to the burner.
In Figure 15, part 2 represents the moveable cap or burner, which slides
upon the wick holder, the exterior moveable cone having been removed: In
Figure 16, a is the exterior moveable cone, which slides 'tightly-on.c; the wick
holder, which may have a series of:small hooks round its lower part, or other
convenient part:(as 'at d), to catch the hollow: cylindrical wick, which may be
split up to allow it to slip easily over; e, the inner cylinder, through which air
is admitted from below to the centre of the flame; the wick fin this lamp
also may be surrounded with an outer shollow, cone or cylinder to prevent
evaporation, as a, in Figure 11; but in this case the opening of the reservoir
must be made wider to admit the cone. b, the circular thumb-piece for moving
the cap a; g, a button, which may be omitted, or may be used for the purpose
of collecting heat from the flame, and transmitting it to the wick through the
inner cylinder; h; the slit from which the flame issues.
What I here claim; in respect to this fourth part of my Invention, is, an
improvement in the construction of lamps, in which volatile substances'are
converted' into vapour by the heat evolved in the burner of the lamp, videlicet,
by the formation of a burner, in which the vapour escapes from a slit or jet;
the size of which may be made adjustable; and the adaptation, to the wick of
such lamps of a case or cover; so as to prevent evaporation from the wick
within the reservoir, in the manner described above.
I now come to the fifth part of my Invention, videlicet, to the improvement
in the construction of burners. This part of my Invention refers to burners
adapted to the combustion of vaporized gas or air, produced by the method
explained in the third part of my Specification; and also to the combustion of
illuminating gases in general for the purposes of light.
..
And I will 'state, generally, for: the more ready: application of my vaporized
air, that if atmospheric air be the vehicle of the vapour, it' will usually require
jets or apertures of larger size than is usual in gas burners for the.production
of a flame of equal size with that of a flame from an equal or less bulk of
illuminating gas, and the same will. be the case if the vehicle of the vapour be
any other non-combustible gas, that is, a gas, which will not combine with
oxygen on ignition. And if atmospheric air be the vehicle of the vapour, the
jets may be smaller, according 'as it is more charged with vapour, which
will depend in practice partly on the temperature of..the air and. partly on the
volatility of the spirituous substance used... Any of the usual forms of gas
burners may be adapted to the combustion..of air or gases charged with
the
vapour of these spirituous substances, with...the modification of increasing

page_text: the size of the jet holes, from which it escapes for combustion, according
to the quantity of luminiferous vapour contained in the air or gas to be burned.
And with regard to the application of the principle of the burners: here
described to the combustion of gas or atmospheric air charged with the vapour
of a spirituous, substance. less volatile than the crude benzole, wliere the
whole system is comprised in one compact apparatus, I pass the tube which
conducts the air to the reservoir or evaporating vessel through a button or
cap in the burner, so as to heat or warm the current of air as it passes.
This arrangement is shewn in the Drawing, Figure 10. The principle of
the burners, which are the subject of this part of my Invention, is
that of offering for the escape of the air or gas a slit or hole, the size
of which is adjustable by a simple mechanical movement of part of the
burner, so as to admit of the escape of a greater or less quantity of air or gas
at once, which may be adjusted without extinguishing the flame, so that the
most perfect luminosity obtainable from the pressure and quality of the
vaporized air or gas passing at any time may be ensured. And as applied to
coal gas and other illuminating gas, these burners have the additional
advantage of offering the thinnest possible film of combustible gas to the, air,
yet so that the orifice, however small, admits of easily. being cleaned by
removing one of the moveable parts of the burner.
The principle is the same as that applied to, the lamps for burning the mixed
oils and spirits as above described, and admits of a variety of forms, in which,
as before, the vertical section may be varied in proportion or form, or the
horizontal section of the burner may be oval, square, &c. ; but I prefer the
circular form, and either of the vertical walls of the burner chamber may be
made moveable, or both may be made moveable, and the moveable part may
be made to move upon the fixed part either by a screw, or by the sliding
contact of two air-tight simple surfaces. The accompanying Drawings shew
various forms which I have selected to render the principle more easily
understood.
Figures 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, represent burners for the combustion of
vaporized gas or air, or of common illuminating gas, in which the sizes of the
orifices, slits, or jets from which the gas or air issues for combustion are
alterable by the movement' of a moveable part or parts of the burners.
Figures 1, 2, 3, 4, are burners in which air is not admitted to the centre of
the flame by a special channel. a is the moveable part, which, as it is raised
or depressed, modifies the size of the orifice; b, the thumb-piece, which may be
made of non-conducting material to protect the fingers from the heat; c, the
orifice or jet hole. In Figures 1, 2, 3, the moveable part is a button in the

page_text: middle of the flame, which may be of various forms. In Figure 4, the move-
able part is a cap, which forms the outer part of the burner. Figures 5, 6, 7,
8, 9, are burners in which air is admitted through the middle of the burner.
Figure 5 is a burner, in which the moveable part is a cap, consisting of two
concentric cylinders or cones, which meet and are joined at their upper edge,
which is perforated with a certain number of slits or holes, which may be of
various forms. These slits or holes should be separated from each other by a
space not perforated, which space should not be smaller than the length of the
slits or holes. The fixed part of the burner is exactly similar, and perforated
with holes similar in form and position to those of the moveable part, but just
so much smaller that the cap fits tightly over it. The adjustment of the size of
the orifices or jets for the escape of the vapour is made by turning the cap
round on the fixed part of the burner, so that a greater or less fraction of each
of the holes in the two parts of the burner shall coincide; this form of burner
requires a circular horizontal section. Figure 5, part 1, is a vertical section
of the burner. Figure 5, parts 2 and 3, are plans of two different caps for
such burners, with different forms and numbers of perforations. a is the
moveable cap; 6 is its circular thumb-piece for turning it; c are the perfora-
tions in the cap. Figures 6, 7, 8, 9, are burners arranged to produce a con-
tinuous film of flame issuing from a circular slit or orifice at c. Each Drawing
is in vertical section. Each of these burners, consists chiefly of two walls, an
In
outer and an inner one, one or both of which may be made moveable.
Figures 6 and 8 the inner cylindrical or conical wall is moveable, and is
suited in Figure 6 to produce a diverging flame, and in Figure 8 a conical
or converging flame.
In Figure 6, the moveable part is supposed to be adjustable by a screw in
7,8,9, by simple sliding contact of the curved surfaces. In Figure 7, the
outer cylindrical or conical wall is shewn as moveable; and in Figure 9, both
the inner and the outer are supposed moveable. In the respective Figures
a, a', are the moveable cones or cylinders; and b, 6, the thumb-pieces for
moving them. All the above burners, or the numerous modifications of which
they admit, should be provided with stop-cocks for extinguishing the flame, as
well as for altering the pressure of the gas or air at the burner. Figure 10
represents a burner which may be used for consuming, by the aid of a current
of air which is heated in the burner, hydrocarbons less volatile than benzole, and
not yielding sufficient vapour to a current of cold air. a, the tube, by which
the air ascends to b, the button or chamber, so placed in the middle of the
burner that the flame may heat it; c, the tube (which may be contained
during part of its descent within the tube b), by which the air descends to the
D

page_text: reservoir or evaporating vessel e; f, the tube and its branches, by which the
vaporized air ascends to the burner; g, the burner, similar in form and principle
to that shewn at Figure 7..
What I claim in respect to this fifth part of my Invention is, the construc-
tion of burners suited to the combustion of illuminating gas, or of air or gas
charged with the vapour of spirituous substances, so that the size of the slits
or jets from which such air or gas issues for combustion may be adjusted by
the movement of a moveable part or parts of the burners.
In witness whereof, I, the said Charles Blachford Mansfield, have here-
unto set my hand and seal, this Nineteenth day of April, in the year of
our Lord One thousand eight hundred and forty-eight.