the first instance in the following manner : Tubes containing
portions of the above rectified products were introduced into a
freezing mixture at ; many of them became turbid, probably
from the presence of water; one received at 176 (by which is
meant that that was the boiling-point of the contents of the
retort when it came over) became partly solid, crystals forming
round the side, and a fluid remaining in the centre ; whilst two
other portions, one received at 186 and the other at 190,
became quite hard. A cold glass rod being introduced into
one of these tubes, the mass within was found to resist con-
siderable pressure ; but by breaking it down, a solid part was
thrust to the bottom of the tube, whilst a fluid remained above:
the fluid was poured off, and in this way the solid portion partly
purified. The contents of the tube were then allowed to fuse,
were introduced into a larger and stronger tube, furnished
with another which entered loosely within it, both being closed
of course at the lower end ; then again lowering the tempera-
ture of the whole to 0, bibulous paper was introduced, and
pressed on to the surface of the solid substance in the large
tube by the end of the smaller one. In this wav much fluid
158 On new Compounds [1825.
was removed by successive portions of paper, and a solid sub-
stance remained, which did not become fluid until raised to
28 or 29. To complete the separation of the permanently
fluid part, the substance was allowed to melt, then cast into a
cake in a tin-foil mould, and pressed between many folds of
bibulous paper in a Bramah's press, care having been taken to
cool the paper, tin-foil, flannel, boards, and other things used,
as near to as possible, to prevent solution of the solid sub-
stance in the fluid part to be removed. It was ultimately
distilled from off caustic lime, to separate any water it might
The general process, which appears to me to be the best for
the preparation of this substance only, is to distil a portion of
the fluid deposited during the condensation of oil-gas.,, to set
aside the product obtained before the temperature rises to
170, to collect that which comes over by 180, again separately
that which comes over by 190, and also the portion up to 200
or 210. That before 170 will upon re-distillation yield por-
tions to be added to those of 180 and 190; and the part
obtained from 190 upwards will also, when re-distilled, yield
quantities boiling over at 180, 190, &c. Having then these
three portions obtained at 180, 190, and 200, let them be
rectified one after the other, and the products between 175
and 195 received in three or four parts at successive tempera-
tures. Then proceed with these as before described.
It will sometimes happen, when the proportion of bicarburet
of hydrogen is small in the liquid, that the rectifications must
be many times repeated before the fluids at 185 and 190 will
deposit crystals on cooling ; that is to say, before sufficient
of the permanently fluid part at low temperatures has been
removed, to leave a solution so saturated as to crystallize at 0.
Bicarburet of hydrogen appears in common circumstances
as a colourless transparent liquid, having an odour resembling
that of oil-gas, and partaking also of that of almonds. Its
specific gravity is nearly 0*85 at 60. When cooled to about
32 it crystallizes, becoming solid ; and the portions which
are on the sides of the glass exhibit dendritical forms. By
leaving tubes containing thin solid films of it in ice-cold water,
and allowing the temperature to rise slowly, its fusing-point
was found to be very nearly 42 F. ; but when liquid, it may,
1825.] obtained by the Decomposition of Oil. 159
like water and some saline solutions, be cooled much below
that point before any part becomes solid. It contracts very
much on congealing, 9 parts in bulk becoming 8 very nearly ;
hence its specific gravity in that state is about 0*956. At
it appears as a white or transparent substance, brittle, pulveru-
lent, and of the hardness nearly of loaf-sugar.
It evaporates entirely when exposed to the air. Its boiling-
point in contact with glass is 186. The specific gravity of
its vapour, corrected to a temperature of 60, is nearly 40,
hydrogen being 1 ; for 2'3 grains became 3*52 cubic inches of
vapour at 212. Barometer 29*98. Other experiments gave
a mean approaching very closely to this result.
It does not conduct electricity.
This substance is very slightly soluble in water ; very soluble
in fixed and volatile oils, in ether, alcohol, &c. ; the alcoholic
solution being precipitated by water. It burns with a bright
flame and much smoke. When admitted to oxygen gas, so
much vapour rises as to make a powerful detonating mixture.
When passed through a red-hot tube, it gradually deposits
carbon, yielding carburetted hydrogen gas.
Chlorine introduced to the substance in a retort exerted but
little action until placed in sunlight, when dense fumes were
formed, without the evolution of much heat; and ultimately
much muriatic acid was produced, and two other substances,
one a solid crystalline body, the other a dense thick fluid. It
was found by further examination, that neither of these were
soluble in water ; that both were soluble in alcohol the liquid
readily, the solid with more difficulty. Both of them appeared
to be triple compounds of chlorine, carbon, and hydrogen ;
but I reserve the consideration of these, and of other similar
compounds, to another opportunity.
Iodine appears to exert no action upon the substance in
several days in sunlight; it dissolves in the liquid in small
quantity, forming a crimson solution.
Potassium heated in the liquid did not lose its brilliancy, or
exert any action upon it, at a temperature of 186.
Solution of alkalies, or their carbonates, had no action
Nitric acid acted slowly upon the substance and became
red, the fluid remaining colourless. When cooled to 3% 9 the
160 On some new Products [1825.
substance became solid and of a fine red colour, which dis-
appeared upon fusion. The odour of the substance with the
acid was exceedingly like that of almonds, and it is probable
that hydrocyanic acid was formed. When washed with water,
it appeared to have undergone little or no change.
Sulphuric acid added to it over mercury exerted a moderate
action upon it, little or no heat was evolved, no blackening
took place, no sulphurous acid was formed ; but the acid
became of a light yellow colour, and a portion of a clear
colourless fluid floated, which appeared to be a product of the
action. When separated, it was found to be bright and clear,
not affected by water or more sulphuric acid, solidifying at
about 34, and being then white, crystalline, and dendritical.
The substance was lighter than water, soluble in alcohol, the
solution being precipitated by a small quantity of water, but
becoming clear by great excess*.
With regard to the composition of this substance^ my ex-
periments tend to prove it a binary compound of carbon and
hydrogen, two proportionals of the former element being united
to one of the latter. The absence of oxygen is proved by the
inaction of potassium, and the results obtained when passed
through a red-hot tube.
The following is a result obtained when it was passed in
* The action of sulphuric acid on this and the other compounds to be
described is very remarkable. It is frequently accompanied with heat ; and
large quantities of those bodies which have elasticity enough to exist as
vapours when alone at common pressures, are absorbed. No sulphurous acid
is produced ; nor when the acid is diluted does any separation of the gas,
vapour, or substance take place, except of a small portion of a peculiar pro-
duct resulting from the action of the acid on the substances, and dissolved by
it. The acid combines directly with carbon and hydrogen ; and I find when
united with bases forms a peculiar class of salts, somewhat resembling the
sulphovinates, but still different from them. I find also that sulphuric acid
will condense and combine with olefiant gas, no carbon being separated, or
sulphurous or carbonic acid being formed ; and this absorption has in the course
of eighteen days amounted to 847 volumes of olefiant gas to one volume of
sulphuric acid. The acid produced combines with bases, &c., forming peculiar
salts, which I have not yet had time, but which it is my intention to examine,
as well as the products formed by the action of sulphuric acid on naphtha,
essential oils, &c., and even upon starch and lignine, in the production of
sugar, guin, &c., where no carbonization takes place, but where similar result*
seem to occur.
1825.] obtained by the Decomposition of Oil. 161
vapour over heated oxide of copper: 0*776 grain of the sub-
stance produced 5*6 cubic inches of carbonic acid gas, at a
temperature of 60, and pressure 29*98 inches; and 0*58 grain
of water was collected. The 5*6 cubic inches of gas are
equivalent to 0*711704 grain of carbon by calculation, and the
0*58 grain of water to 0*064444 of hydrogen.
Carbon 0*711704 or 11*44
Hydrogen 0*064444 or !
These quantities nearly equal in weight the weight of the sub-
stance used ; and making the hydrogen 1, the carbon is not
far removed from 12, or two proportionals.
Four other experiments gave results all approximating to
the above. The mean result was 1 hydrogen, 1 I '576 carbon.
Now considering that the substance must, according to the
manner in which it was prepared, still retain a portion of the
body boiling at 186, but remaining fluid at 0, and which
substance I find, as will be seen hereafter, to contain less car-
bon than the crystalline compound (only about 8*25 to 1 of
hydrogen), it may be admitted, I think, that the constant
though small deficit of carbon found in the experiments is due
to the portion so retained ; and that the crystalline compound
would, if pure, yield 12 of carbon for each 1 of hydrogen, or
two proportionals of the former element and one of the latter.
2 proportionals Carbon 12\ 10 , . , , ,
1 Hydrogen j |> 3 b.carburet of hydrogen.
This result is confirmed by such data as I have been able to
obtain by detonating the vapour of the substance with oxygen.
Thus in one experiment 8092 mercury grain measures of oxy-
gen at 62 had such quantity of the substance introduced
into it as would entirely rise in vapour ; the volume increased
to 8505: hence the vapour amounted to 413 parts, or ^^of
the mixture nearly. Seven volumes of this mixture were
detonated in a eudiometer tube by an electric spark, and
diminished in consequence nearly to 6'1 : these, acted upon by
potash, were further diminished to 4, which were pure oxygen.
Hence 3 volumes of mixture had been detonated, of which
nearly 0*34 was vapour of the substance, and 2*65 oxygen.
The carbonic acid amounted to 2'1 volumes, and must have
consumed an equal bulk of oxygen gas ; so that 0*55 remain
162 On some new Products [1825.
as the quantity of oxygen which has combined with the hydro-
gen to form water, and which with the 0*34- of vapour nearly
make the diminution of 0*9.
It will be seen at once that the oxygen required for the car-
bon is four times that for the hydrogen ; and that the whole
statement is but little different from the following theoretical
one, deduced partly from the former experiments : 1 volume
of vapour requires 7*5 volumes of oxygen for its combustion ;
6 of the latter combine with carbon to form 6 of carbonic acid,
and the 1*5 remaining combine with hydrogen to form water.
The hydrogen present therefore in this compound is equivalent
to 3 volumes, though condensed into one volume in union with
the carbon ; and of the latter elements there are present six
proportionals, or 36 by weight. A volume therefore of the
substance in vapour contains
Carbon .... 6x6=36
Hydrogen . . . . 1 x3= 3
and its weight or specific gravity will be 39, hydrogen being 1.
Other experiments of the same kind gave results according
Among the liquid products obtained from the original fluid
was one which, procured as before mentioned, by submitting
to the portion distilling over at 180 or 190, Corresponded
with the substance already described, as to boiling-points, but
differed from it in remaining fluid at low temperatures ; and I
was desirous of comparing the two together. I had no means
of separating this body from the bicarburet of hydrogen, of
which it would of course be a saturated solution at 0. Its
boiling-point was very constantly 186. In its general cha-
racters of solubility, combustibility, action of potassium, &c.,
it agreed with the substance already described. Its specific
gravity was 0*86 at 60. When raised in vapour, 1*11 grain of
it gave 1*573 cubic inch of vapour at 212, equal to 1*212 cubic
inch at 60. Hence 100 cubic inches would weigh about 91*6
grains, and its specific gravity would be 43*25 nearly. In
another experiment, 1*72 grain gave 2*4 cubic inches at 212,
equal to 1*849 cubic inch at 60; from which the weight of 100
1825.] obtained by the Decomposition of Oil. 163
cubic inches would be deduced as 93 grains ; and its specific
gravity to hydrogen as 44- to 1. Hence probably the reason
why, experimentally, the specific gravity of bicarburet of hy-
drogen in vapour was found higher than by theory it would
appear to be when pure.
Sulphuric acid acted much more powerfully upon this sub-
stance than upon the bicarburet ; great heat was evolved,
much discoloration occasioned, and a separation took place
into a thick black acid, and a yellow lighter liquid, resisting
any further action at common temperatures.
0*64 grain of this substance was passed over heated oxide
of copper: 4*51 cubic inches of carbonic acid gas were ob-
tained, and 0*6 grain of water. The carbonic acid and water
are equivalent to
Carbon v/. - '-. '-,, : , . : . 0-573176, or 8-764
Hydrogen .... 0*066666, or 1-
but as the substance must have contained much bicarburet
of hydrogen, it is evident that, if in a pure state, the carbon
would fall far short of the above quantity, and the compound
would approximate of course to a simple carburet of hydrogen
containing single proportionals.
New Carburet of Hydrogen. Of the various other products
from the condensed liquor, the next most definite to the bi-
carburet of hydrogen appears to be that which is most volatile.
If a portion of the original liquid be warmed by the hand or
otherwise, and the vapour which passes off be passed through
a tube at 0, very little uncondensed vapour will go on to the
mercurial trough ; but there will be found after a time a por-
tion of fluid in the tube, distinguished by the following pro-
perties. Though a liquid at 0, it upon slight elevation of
temperature begins to boil, and before it has attained 32 is all
resolved into vapour or gas, which may be received and pre-
served over mercury.
This gas is very combustible, and burns with a brilliant
flame. The specific gravity of the portion I obtained was
between 27 and 28, hydrogen being 1 ; for 39 cubic inches
introduced into an exhausted glass globe were found to increase
its weight 22-4 grains at 60 F., bar. 29'94. Hence 100 cubic
inches weigh nearly 57*44 grains.
164 On some new Products [1825.
When cooled to it condensed again ; and enclosed in this
state in a tube of known capacity, and hermetically sealed up,
the bulk of a given weight of the substance at common tem-
peratures was ascertained. This compared with water gave
the specific gravity of the liquid as 0'627 at 54. It is there-
fore among solids' or liquids the lightest body known.
This gas or vapour when agitated with water is absorbed in
small quantities. Alcohol dissolves it in large quantity ; and
a solution is obtained, which, upon the addition of water,
effervesces, and a considerable quantity of the gas is liberated.
The alcoholic solution has a peculiar taste, and is neutral to
Olive oil dissolves about six volumes of the gas.
Solution of alkali does not affect it ; nor does muriatic acid.
Sulphuric acid condenses the gas in very large quantity,
one volume of the acid condensing above 100 volumes of the
vapour. Sometimes the condensation is perfect ; at other times
a small quantity of residual gas is left, which burns with a pale
blue flame, and seems to be a product of too rapid action.
Great heat is produced during the action ; no sulphurous acid
is formed ; the acid is much blackened, has a peculiar odour,
and upon dilution generally becomes turbid, but no gas is
evolved. A permanent compound of the acid with carbon and
hydrogen is produced, and enters as before mentioned into
combination with bases.
A mixture of two volumes of this vapour with fourteen
volumes of pure oxygen was made, and a portion detonated in
a eudiometer tube. 8'8 volumes of the mixture diminished
by the spark to 5*7 volumes, and these by solution of potash
to 1*4 volume, which were oxygen. Hence 7'4 volumes had
been consumed, consisting of
Vapour of substance .... . . 1*1
Carbonic acid formed 4-3
Oxygen in carbonic acid ..... 4*3
Oxygen combining with hydrogen . . 2'0
Diminution by spark , ..... 3*1
This is nearly as if one volume of the vapour or gas had
1825.] obtained by the Decomposition of Oil. 165
required six volumes of oxygen, had consumed four of them
in producing four of carbonic acid gas, and had occupied the
other two by four of hydrogen to form water. Upon which
view, four volumes or proportionals of hydrogen = 4, are com-
bined with four proportionals of carbon =24, to form one
volume of the vapour, the specific gravity of which would
therefore be 28. Now this is but little removed from the
actual specific gravity obtained by the preceding experiments ;
and knowing that this vapour must contain small portions
of other substances in solution, there appears no reason to
doubt that, if obtained pure, it would be found thus con-
As the proportions of the elements in this vapour appear to
be the same as in olefiant gas, it became interesting to ascertain
whether chlorine had the same action upon it as on the latter
body. Chlorine and the vapour were therefore mixed in an
exhausted retort: rapid combination took place, much heat
was evolved, and a liquor produced resembling hydrochloride
of carbon, or the substance obtained by the same process from
olefiant gas. It was transparent, colourless, and heavier than
water. It had the same sweet taste, but accompanied by an
after aromatic bitterness, very persistent. Further, it was
composed of nearly equal volumes of the vapour and chlorine :
it could not therefore be the same as the hydrochloride of
carbon from olefiant gas, since it contained twice as much car-
bon and hydrogen. It was therefore treated with excess of
chlorine in sunlight: action slowly took place, more chlorine
combined with the substance, muriatic acid was formed, and
ultimately a fluid tenacious triple compound of chlorine, car-
bon, and hydrogen was obtained ; but no chloride of carbon.
This is a remarkable circumstance, and assists in showing that
though the elements are the same, and in the same proportions
as in olefiant gas, they are in a very different state of combi-
The tension of the most volatile part of the condensed oil-
gas liquid, and indeed of the substance next beneath olefiant
gas in elasticity existing in the mixture constituting oil-gas,
appears to be equal to about four atmospheres at the tempe-
rature of 60. To ascertain this a tube was prepared, like the
166 On some new Products [1825.
one* delineated in the sketch, fig. 1, containing a mercurial
gauge at a, c, and the extremities being open. It was then
cooled to from a to b, and in that state made the receiver
into which the first product from a portion of the original fluid
was distilled. The part at b was then closed by a spirit-lamp ;
and having raised enough vapour to make it issue at c, that
was also closed. The apparatus now placed as at fig. 2, had
a and d cooled to 0, whilst the fluid collected in b was warmed
by the hand or the air ; and when a portion had collected in d
sufficient for the purpose, the whole instrument was immersed
in water at 60 ; and before the vapour had returned and been
all dissolved by the liquid at b, the pressure upon the gauge
within was noted. Sometimes the fluid at d was rectified by
warming that part of the tube and cooling a only, the re-
absorption at b being prevented or rather retarded in con-
sequence of the superior levity of the fluid at d; so that the
first portions which returned to b lay upon it in a stratum, and
prevented sudden solution in the mass below. This difference
in specific gravity was easily seen upon agitation, in conse-
quence of the striaB produced during the mixture.
Proceeding in this way, it was found, as before stated, that
the highest elastic power that could be obtained from the sub-
stances in the tube was about four atmospheres at 60; and as
there seems no reason to doubt but that portions of the most
volatile substances in oil-gas beneath olefiant gas were con-
* The particular inclination of the parts of the tube one to another was
given, that the fluid, when required, might be returned from a to d without
passing on to b. .
1825.] obtained by the Decomposition of Oil. 167
tained in the fluid, inasmuch as even olefiant gas itself is dis-
solved by it in small proportions, it may be presumed that
there is no substance in oil-gas much more volatile than the
one requiring a pressure of four atmospheres at 60, except
the well-known compounds ; or, in other words, that there is
not a series of substances passing upwards from this body to
olefiant gas, and possessing every intermediate degree of elas-
ticity, as there seems to be from this body downwards, to com-
pounds requiring 250 or 300 for their ebullition.
In reference to these more volatile products, I may state
that I have frequently observed a substance come over in
small quantity, rising with the vapour which boils off at 50 or
60, and crystallizing in spiculse in the receiver at 0. A tem-
perature of 8 or 10 causes its fusion and disappearance. It
is doubtless a peculiar and definite body, but the quantity is
extremely small, or else it is very soluble in the accompanying
fluids. I have not yet been able to separate it, or examine it
I ventured some time since upon the condensation of various
gases *, to suggest the possibility of forming a vapour lamp,
which containing a brilliantly combustible substance (liquid at
a pressure of two, three, or four atmospheres at common tem-
peratures, but a vapour at less pressure), should furnish a
constant light for a length of time, without requiring high or
involving inconstant pressure. Such a lamp I have now formed,
feeding it with the substance just described; and though at
present it is only a matter of curiosity, and perhaps may con-
tinue so, yet there is a possibility that processes may be de-
vised, by which the substance may be formed in larger quantity,
and render an application of this kind practically useful.
On the remaining portions of the condensed Oil-gas Liquor.
It has been before mentioned, that by repeated distillations
various products were obtained, boiling within limits of tem-
perature which did not vary much, and which when distilled
were not resolved into other portions, differing far from each
other in volatility, as always happened in the earlier distilla-
tions. Though conscious that these were mixtures, perhaps
of unknown bodies, and certainly in unknown proportions,
yet experiments were made on their composition by passing
* Quarterly Journal of Science, xvi. 240, and page 134.
168 On some new Products [1825.
them over oxide of copper, in hopes of results which might
assist in suggesting correct views of their nature. They all
appeared to be binary compounds of carbon and hydrogen,
and the following Table exhibits the proportions obtained;
the first column expressing the boiling temperature at which
the products were distilled, as before mentioned ; the second
the hydrogen, made a constant quantity ; and the third the
140 . . 7-58
These substances generally possess the properties before
described, as belonging to the bicarburet of hydrogen. They
all resist the action of alkali, even that which requires a tem-
perature above 250 for its ebullition ; and in that point are