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at any time convey a very definite idea, and the analogous name
of iodic aether would evidently be very improper for a solid cry-
stalline body heavier than sulphuric acid. Mr. Brande has
suggested the names of hydriodide of carbon and hydrochlo-
ride of carbon for these two bodies. Perhaps, as their ge-
neral properties range with those of the combustibles, while the
specific nature of the compound is decided by the supporter of



1821.] On a new Compound of Chlorine and Carbon. 53

combustion which is in combination, the terms of hydrocar-
buret of chlorine and hydrocarburet of iodine may be con-
sidered as appropriate for them.

As yet, I have not succeeded in procuring an iodide of carbon,
but I intend to pursue these experiments in a brighter season
of the year, and expect to obtain this compound.



On a new Compound of Chlorine and Carbon.
By PHILLIPS and FARADAY*.

[Read July 12, 1821.]

M. JULIN, of Abo in Finland, is proprietor of a manufactory,
in which nitric acid is prepared by distilling calcined sulphate
of iron with crude nitre in iron retorts, and collecting the pro-
ducts in receivers connected by glass tubes, in the manner of
Woulfe's apparatus. In this process he observed, that when a
peculiar kind of calcined vitriol, obtained from the waters of
the mine of Fahlun, and containing a small portion of pyrites,
known in Sweden by the name of calcined aquafortis vitriol
No. 3, was used, the first tube was lined with sulphur, and the
second with fine white feathery crystals. These were in very
small quantity, amounting only to a few grains from each distil-
lation ; but M. Julin, by degrees, collected a portion of it, and,
having brought it to this country, inserted a short account of
its properties in the 'Annals of Philosophy,' vol. i. p. 216, to
which a few observations were added by ourselves.

The following are the properties of this substance, as de-
scribed by M. Julin. It is white ; consists of small soft ad-
hesive fibres ; sinks slowly in water ; is insoluble in it whether
hot or cold ; is tasteless ; has a peculiar smell, somewhat
resembling spermaceti ; is not acted on by sulphuric, muriatic,
or nitric acid, except that the latter by boiling on it gives traces
of sulphuric acid ; boiled with caustic potash, has a small por-
tion of sulphur dissolved from it ; dissolves in hot oil of turpen-
tine, but most of it crystallizes in needles from the solution on
cooling; dissolves in boiling alcohol of *816, but by far the
greater part crystallizes on cooling ; burns in the flame of a
lamp with a greenish-blue flame, giving a slight smell of chlorine

* Phil. Trans. 1821, p. 392, and Phil. Mag. lix. p. 33.



54 On a new Compound of Chlorine and Carbon. [1821.

gas ; 'when heated, melting, boiling, and subliming at a tempe-
rature between 350 and 400, and subliming slowly without
melting at a heat of about 250, forming long needles. Potas-
sium burned with a vivid flame in its vapour in an open tube,
and carbon was deposited ; a solution made of the residuum,
and saturated with nitric acid, gave a copious precipitate with
nitrate of silver. M. Julin then remarks, that the small quan-
tity he possessed, with want of leisure, prevented him from
making any further experiments on it, and concludes by com-
paring it with the chlorides of carbon that have lately been
formed.

The small quantity of the substance which, by the kindness
of M. Julin, we had at our disposal at that time, was insufficient
to enable us satisfactorily to ascertain its nature. We found it
mixed with free sulphur, and sulphate and muriate of ammonia.
When purified, our first object, in consequence of M. Julin's
suggestion, was to compare it with the perchloride of carbon,
but it was found entirely distinct from it in its properties.

Since M. Julin's return from the continent, he has very
kindly placed some further portions of this substance at our
disposal. We have therefore been enabled to continue our
experiments, and have come to the very unexpected conclusion
of its being another chloride of carbon, in addition to the two,
an account of which has been published in the Transactions of
the Royal Society for this year.

The substance, after being boiled in solution of potash,
washed in water, dried and sublimed, formed beautiful acicular
crystals, which appeared to Mr. W. Phillips to be four-sided
prisms. They contained no sulphur, and, when dissolved in
alcohol or aether, gave no traces of chlorine or muriates by
nitrate of silver. They burned in the air with a strong bright
flame at a heat below redness, and agreed with the description
given by M. Julin of the properties of the substance.

When heated moderately, it sublimed unaltered ; but on
passing a portion over rock-crystal, heated to bright redness,
in a green glass tube, it^ was decomposed, charcoal was depo-
sited, and the gas, passed into solution of nitrate of silver, pre-
cipitated it, and proved to be chlorine.

A portion was repeatedly sublimed in a small retort filled
with chlorine, which was made red-hot in several places ; it



On a new Compound of Chlorine and Carbon. 55

however underwent no change, but on cooling crystallized as
at first. It was also exposed in the same gas to sunlight for
many days, but no change took place.

When raised in vapour over hot mercury, and detonated with
excess of oxygen, a quantity of carbonic acid gas and chloride
of mercury were produced. There was no change in the
volume of gas used ; and lime-water being passed into it ab-
sorbed the carbonic gas, became turbid, and left a residuum of
pure oxygen. Acetic acid being then added, to dissolve the
carbonate of lime, the solution was tested for chlorine, which
was readily found in it. When detonated with oxygen, the
substance being in excess, there was expansion of volume, car-
bonic oxide, carbonic acid and chloride of mercury being formed.

When phosphorus, iron, tin, &c. were heated to redness in
its vapour over mercury, it was decomposed, chlorides of those
substances being formed, and charcoal deposited ; and M. Julin
has shown that the same effect is produced by potassium.

Three grains of this substance were passed in vapour over
pure peroxide of copper, heated to redness in a green glass
tube : a very small portion passed undecomposed. The gas
received over mercury equalled 5*7 cubic inches ; it was car-
bonic acid gas. A small part of the oxiHe of copper was re-
duced, and portions of a crystalline body appeared within the
tube, which, on examination, proved to be chloride of copper.
Some of this was used in making experiments on its nature ;
but when that was ascertained, the remaining contents of the
tube were dissolved in nitric acid, and precipitated by nitrate
of silver: 6'1 grains of chloride of silver were obtained.

Two grains were passed over pure quick-lime, raised to a
red heat in a green glass tube. The moment the vapour came
in contact with the hot lime, ignition took place, and the earth
burned as long as the vapour passed over it. When cold, the
tube was examined, and much charcoal found deposited at the
spot where the ignition occurred. The contents of the tube
were dissolved in nitric acid, and the filtered solution precipi-
tated by nitrate of silver: 5*9 grains of chloride of silver were
obtained.

These results afford us sufficient data from which to deduce
the nature and composition of this body. All the experiments
of decomposition indicate it to contain chlorine and carbon, and



56 On a new Compound of Chlorine and Carbon. [1821.

those with oxygen and the metals sufficiently prove the absence
of hydrogen and oxygen. With regard to the proportions of
the elements, three grains of the substance gave 5*7 cubic
inches of carbonic acid gas, therefore two grains will give S'S
cubic inches. One hundred cubic inches of carbonic acid gas
weigh 46*47 grains, and contain 12*72 grains of carbon; and
3*8 cubic inches will therefore contain 0*483 grain of carbon.
The two grains of the substance decomposed by heated lime
gave 5*9 grains of chloride of silver, which, according to
Dr. Wollaston's scale, equal 1*45 of chlorine; hence the two
grains gave

Chlorine . ... . ... . 1*45

Carbon ....... '483



The loss here is 0*067, which is by no means important, when
the small quantity of the substance and the nature of the ex-
periments are considered.

As to the proportion of these two bodies to each other, if we
consider chlorine as represented by 33*5 and carbon by 5*7, or
with Dr. Wollaston by 44*1 and 7*5, then the 1*45 of chlorine
would be equivalent.to 0*2466 of carbon. This is the constitu-
tion of the fluid or protochloride of carbon ; and if we double
the 0*2466, the product 0*4932 approaches so near to the ex-
perimental result 0*483, that we do not hesitate to regard this
compound as consisting of one portion of chlorine and two por-
tions of carbon, or

Chlorine .... V' V 44-1 33-5
Carbon ..... . . 15 11-4

It is remarkable that another of these compounds should be
found so soon after the discovery of the two former chlorides of
carbon. Its physical properties and its chemical energies are
in every respect analogous to those of the former compounds ;
and its constitution increases the probability that another
chloride of carbon may be found, consisting of two portions of
chlorine and one of carbon.

All the endeavours we have yet made to form the chloride of
carbon now described, or to convert it into either of the other
chlorides, have been unsuccessful. We expected that when
decomposed by heat, it would produce the protochloride with



On the Vapour of Mercury at common Temperatures. 57

the liberation of carbon, as the perchloride does with the libera-
tion of chlorine, but we have not yet been able to ascertain that
point. We have only to offer as an apology for this and other
imperfections in the present paper, the smallness of the quan-
tity of this substance that we possessed.



On the Vapour of Mercury at common Temperatures*.

IT has long been admitted, that in the upper part of the baro-
meter and thermometer an atmosphere of mercury exists, even
at common temperatures, but having a very small degree of
tension. The following experiment renders it easy to show
this atmosphere even when the air has not, as in the instruments
above mentioned, been removed. A small portion of mercury
was put through a funnel into a clean dry bottle, capable of
holding about six ounces, and formed a stratum at the bottom
not one-eighth of an inch in thickness : particular care was taken
that none of the mercury should adhere to the upper part of
the inside of the bottle. A small piece of leaf-gold was then
attached to the under part of the stopper of the bottle, so
that when the stopper was put into its place, the leaf-gold was
enclosed in the bottle. It was then set aside in a safe place,
which happened to be both dark and cool, and left for between
six weeks and two months. At the end of that time it was ex-
amined, and the leaf-gold was found whitened by a quantity of
mercury, though every part of the bottle and mercury remained
apparently just as before.

This experiment has been repeated several times, and always
with success. The utmost care was taken that mercury should
not get to the gold, except by passing through the atmosphere
of the bottle. I think therefore it proves, that at common
temperatures, and even when the air is present, mercury is
always surrounded by an atmosphere of the same substance.



Experiments on the Alloys of Steel, made with a View to its

Improvement. By STODART and FARADAY f
IN proposing a series of experiments on the alloys of iron and
steel with various other metals, the object in view was twofold:

* Quarterly Journal of Science, x. 354. f Ibid. ix. 319.



58 On the Alloys of Steel. [1820.

first, to ascertain whether any alloy could be artificially
formed, better, for the purpose of making cutting-instruments,
than steel in its purest state ; and secondly, whether any
such alloys would, under similar circumstances, prove less sus-
ceptible of oxidation ; new metallic combinations for reflecting
mirrors were also a collateral object of research.

Such a series of experiments were not commenced without
anticipating considerable difficulties, but the facilities afforded
us in the laboratory of the Royal Institution, where they were
made, have obviated many of them. The subject was new, arid
opened into a large and interesting field. Almost an infinity
of different metallic combinations may be made, according to
the nature and relative proportions of the metals capable of
being alloyed. It never has been shown by experiment, whe-
ther pure iron, when combined with a minute portion of carbon,
constitutes the very best material for making edged tools ; or
whether any additional ingredient, such as the earths, or their
bases, or any other metallic matter, may not be advantageously
combined with the steel ; and, if so, what the materials are, and
what the proportion required to form the best alloy for this much
desired and most important purpose. This is confessedly a
subject of difficulty, requiring both time and patient investiga-
tion, and it will perhaps be admitted as some apology for the
very limited progress as yet made.

By referring to the analysis of wootz, or Indian steel*, it will
be observed that only a minute portion of the earths alumina
and silex could be detected, these earths (or their bases) giving
to the wootz its peculiar character. Being satisfied as to the
constituent parts of this excellent steel, it was proposed to
attempt making such a combination, and with this view various
experiments were made. Many of them were fruitless : the
successful method was the following. Pure steel in small
pieces, and in some instances good iron mixed with charcoal
powder, were heated intensely for a long time ; in this way they
formed carburets, which possessed a very dark metallic grey
colour, something in appearance like the black ore of tellurium,
and highly crystalline. When broken, the facets of small but-
tons, not weighing more than 500 grains, were frequently above

* Quarterly Journal of Science, vii. 288.



1820.] On the Alloys of Steel. 59

the eighth of an inch in width. The results of several experi-
ments on its composition, which appeared very uniform, gave
94*36 iron + 5*64 carbon. This being broken and rubbed to
powder in a mortar, was mixed with pure alumina, and the
whole intensely heated in a close crucible for a considerable
time. On being removed from the furnace and opened, an alloy
was obtained of a white colour, a close granular texture, and
very brittle : this, when analysed, gave 6*4 per cent, alumina,
and a portion of carbon not accurately estimated. 700 grains
of good steel, with 40 of the alumine alloy, were fused together,
and formed a very good button, perfectly malleable ; this, on
being forged into a little bar and the surface polished, gave, on
the application of dilute sulphuric acid, the beautiful damask
which will presently be noticed as belonging peculiarly to wootz.
A second experiment was made with 500 grains of the same
steel and 67 of the alumine alloy, and this also proved good ; it
forged well, and gave the damask. This specimen has all the
appreciable characters of the best Bombay wootz.

We have ascertained, by direct experiment, that the wootz,
although repeatedly fused, retains the peculiar property of pre-
senting a damask surface, when forged, polished, and acted
upon by dilute acid. This appearance is apparently produced
by a dissection of the crystals by the acid ; for though by the
hammering the crystals have been bent about, yet their forms
may be readily traced through the curves which the twisting
and hammering have produced. From this uniform appearance
on the surface of wootz, it is highly probable that the much-
admired sabres of Damascus are made from this steel; and if
this be admitted, there can be little reason to doubt that the
damask itself is merely an exhibition of crystallization. That
on wootz it cannot be the effect of the mechanical mixture of
two substances, as iron and steel, unequally acted upon by acid,
is shown by the circumstance of its admitting re-fusion without
losing this property. It is certainly true that a damasked
surface may be produced by welding together wires of iron and
steel ; but if these welded specimens are fused, the damask does
not again appear. Supposing that the damasked surface is de-
pendent on the development of a crystalline structure, then the
superiority of wootz in showing the effect, may fairly be con-
sidered as dependent on its power of crystallizing, when solidi-



60 On the Alloys of Steel. [ 1 820-

fying, in a more marked manner, and in more decided forms
than the common steel. This can only be accounted for by
some difference in the composition of the two bodies, and as it
has been stated that only the earths in small quantities can be
detected, it is reasonable to infer that the bases of these earths
being combined with the iron and carbon render the mass more
crystallizable, and that the structure drawn out by the hammer,
and confused (though not destroyed), does actually occasion the
damask. It is highly probable that the wootz is steel acci-
dentally combined with the metal of the earths, and the irregu-
larity observed in different cakes, and even in the same cake,
is in accordance with this opinion. The earths may be in the
ore, or they may be derived from the crucible in which the
fusion is made.

In making the alumine alloy for the imitation of wootz, we
had occasion to observe the artificial formation of plumbago.
Some of the carburet of iron before mentioned having been
pounded and mixed with fresh charcoal, and then fused, was
found to have been converted into perfect plumbago. This
had not taken place throughout the whole mass ; the metal
had soon melted and run to the bottom ; but having been con-
tinued in the furnace for a considerable time, the surface of the
button had received an additional portion of charcoal, and had
become plumbago. It was soft, sectile, bright, stained paper,
and had every other character of that body ; it was indeed in
no way distinguishable from it. The internal part of these
plumbago buttons was a crystalline carburet : a portion of it
having been powdered and fused several times with charcoal,
at last refused to melt, and on the uncombined charcoal being
burnt away by a low heat, it was found that the whole of the
steel had been converted into plumbago : this powder we at-
tempted to fuse, but were not successful.

It will appear by the following experiment, that we had
formed artificial wootz, at a time when this certainly was not
the object of research. In an attempt to reduce titanium and
combine it with steel, a portion of menachanite was heated with
charcoal, and a fused button obtained. A part of this button
was next fused with some good steel; the proportions were
96 steel, 4 menachanite button. An alloy was formed, which
worked well under the hammer; and the little bar obtained



1820.] On the Alloys of Steel 61

was evidently different from, and certainly superior to, steel.
This was attributed to the presence of titanium, but none
could be found in it ; nor indeed was any found even in the
menachanite button itself. The product was iron and carbon,
combined with the earths or their bases, and was in fact excel-
lent wootz. A beautiful damask was produced on this specimen
by the action of dilute acid. Since this, many attempts have
been made to reduce the oxide of titanium ; it has been heated
intensely with charcoal, oil, &c., but hitherto all have failed .
the oxide has been changed into a black powder, but not fused.
When some of the oxide was mixed with steel filings and a
little charcoal added, on being intensely heated the steel fused,
and ran into a fine globule which was covered by a dark-co-
loured transparent glass, adhering to the sides of the crucible.
The steel contained no titanium ; the glass proved to be oxide
of titanium, with a little oxide of iron. These experiments have
led us to doubt whether titanium has ever been reduced to the
metallic state. From the effects of the heat upon the crucibles,
which became soft and almost fluid, sometimes in fifteen
minutes, we had in fact no reason to suppose the degree of heat
inferior to any before obtained by a furnace : that used in
these last experiments was a blast furnace, supplied by a con-
stant and powerful stream of air ; the fuel good Staffordshire
coke, with a little charcoal ; both Hessian and Cornish crucibles
were used, one being carefully luted into another, and even
three have been united, but they could not be made to stand
the intense heat.

Meteoric iron is, by analysis, always found to contain nickel.
The proportions are various, in the specimens that have been
chemically examined. The iron from the Arctic regions was
found to contain .3 per cent, only of nickel*, while that from
Siberia gave nearly 10 per cent. With the analysis of this
last we are favoured by J. G. Children, Esq., and, having per-
mission from that gentleman, we most willingly insert the ac-
count of this very accurate process :

37 grains of Siberian meteoric iron gave 48*27 grains of per-
oxide of iron and 4'52 grains of oxide of nickel. Supposing

* Quarterly Journal of Science, vi. 369.



62 On the Alloys of Steel. [1820.

the equivalent number for nickel to be 28, these quantities are
equal to Iron .... 33*69

Nickel .... 3-56

37-25
Supposing the quantities to be correctly

Iron .... 33-5
Nickel .... 3-5

"3T 7 "
the proportions per cent, are,

Iron .... 90*54
Nickel .... 9-46

100-00

A second experiment on 47 grains gave 61 grains of per-
oxide of iron =42*57 iron. The ammoniacal solution of nickel
was lost by an accident ; reckoning from the iron, the quan-
tities per cent, are,

Iron .... 90-57
Nickel .... 9-42

99-99

A third experiment on 56 grains gave 73'06 grains peroxide
of iron = 50-99 iron, and 5-4 of oxide of nickel = 4-51 nickel;
or per cent., Iron .... 91*00
Nickel . ". 5 V 8 * 01
Loss .... 0-99

100-00

The mean of the three gives 8*96 per cent, of nickel.

The meteoric iron was dissolved in aqua regia, and the iron,
thrown down by pure ammonia, well washed, and heated red.

Jn the first experiment the ammoniacal solution was evapo-
rated to dryness, the ammonia driven off by heat, and the oxide
of nickel re-dissolved in nitric acid and precipitated by pure
potassa, the mixture being boiled a few seconds.

In the third experiment the nickel was thrown down from
the ammoniacal solution at once by pure potassa. The first
method is best, for a minute portion of oxide of nickel escaped
precipitation in the last experiment, to which the loss is pro-
bably to be attributed.

All the precipitates were heated to redness. J. G, C.



1820.] On the Alloys of Steel. 63

We attempted to make imitations of the meteoric irons with
perfect success. To some good iron (horseshoe nails) were
added 3 per cent, of pure nickel; these were enclosed in
a crucible and exposed to a high temperature in the air-
furnace for some hours. The metals were fused, and on
examining the button, the nickel was found in combination
with the iron. The alloy was taken to the forge, and proved
under the hammer to be quite as malleable and pleasant to
work as pure iron; the colour, when polished, rather whiter.
This specimen, together with a small bar of meteoric iron,
have been exposed to a moist atmosphere ; they are both a
little rusted. In this case it was omitted to expose a piece of
pure iron with them ; it is probable that> under these circum-
stances, the pure iron would have been more acted upon.

The same success attended in making the alloy to imitate
the Siberian meteoric iron agreeably to Mr. Children's analysis.
We fused some of the same good iron with 10 per cent, nickel ;
the metals were found perfectly combined, but less malleable,
being disposed to crack under the hammer. The colour when
polished had a yellow tinge. A piece of this alloy has been
exposed to moist air for a considerable time, together with a
piece of pure iron ; they are both a little rusted, not, however,
to the same extent; that with the nickel being but slightly
acted upon, comparatively to the action on the pure iron :
it thus appears that nickel, when combined with iron, has some
effect in preventing oxidation, though certainly not to the ex-
tent that has at times been attributed to it. It is a curious



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