contain oxalate and malate of potash. Some leaves were tied together
and hung up in a warm and slightly-humid place, where there was but
little light, to dry. Being examined at the end of several months,
they were found penetrated with, and covered by, an immense number
of minute crystals of nitre. The oxalic and malic acids had been
replaced by nitric acid; but whether from animalized matter naturally
in the leaves of the plant, or from the action of the air, or in what
manner, is not known.—M. HENRI BRACONNOT, _Ann. de Chimie_, xxxv. 260.
13. _Experiments on Fluoric Acid and Fluates, by_ M. Kuhlman.—These
experiments were made with dry sulphuric acid and fluor spar, with
the intention of proving that fluor spar is truly a compound of
fluorine and calcium, and not of fluoric acid and oxide of calcium.
A quantity of anhydrous sulphuric acid was prepared with great care,
and collected in a glass tube; the latter was then connected with
a platina tube charged with fluor spar, which had previously been
calcined in a platina crucible, and a glass tube was connected with
the other end of the platina tube for the purpose of conducting and
facilitating the collection of the gas evolved over mercury. The
fluor spar was heated to redness, and then the temperature of the
sulphuric acid raised so as to cause a stream of it in vapour to
pass over the fluor spar; but there was not the slightest reaction,
the sulphuric acid recondensed in part in the farthest tube, and no
trace of fluoric acid was produced. Dry sulphuric acid was then put,
in the liquid state, in contact with dry fluor spar, but there was
no decomposition, and no portion of the spar was converted [p206]
into sulphate of lime. The first experiment was then repeated, with
the difference of using hydrated sulphuric acid of specific gravity
1.842, and there was instantly much fluoric acid produced, which
acted upon the glass.
As Berzelius found 100 parts of fluor spar, when acted upon by
sulphuric acid, to yield 175 parts of sulphate of lime, equal to
73.553 parts of lime, or 52.819 of calcium, it follows that 100
parts of fluoride of calcium should contain 47.181 of fluorine and
52.819 of calcium. By the assistance of this result, and further
experiments, M. Kuhlman proceeded to ascertain the composition of
hydro-fluoric acid. Dry muriatic acid gas was passed over calcined
fluor spar heated to redness in a tube of platina; the fluoride of
calcium was decomposed, free hydro-fluoric acid was evolved, and
chloride of lime remained in the tube. The hydro-fluoric acid acted
upon the glass tubes, but being received in water was entirely
dissolved, with the exception of the silica it had separated from
the glass: no trace of hydrogen appeared. One hundred parts of
fluoride of calcium thus treated became 143.417 parts of chloride of
calcium, the 52.819 parts of calcium having united to 90.598 parts of
chlorine. But this latter quantity must have liberated 2.511 parts of
hydrogen, which must, therefore, have combined with the 47.181 parts
of fluorine in the spar, to form 49.692 parts of hydro-fluoric acid.
This latter body, therefore, consists of 94.941 fluorine, and 5.059
of hydrogen per cent. A small quantity of chlorine was set at liberty
during the experiment, the author thinks, from a little manganese in
the fluor spar.
M. Kuhlman found that all the chlorides, when subjected to the action
of anhydrous sulphuric acid in vapour, resisted decomposition, except
the chloride of sodium, which gave a small quantity of sulphate of
soda, and a double salt of soda and platina, crystallizing in fine
needles of a yellow colour. No doubt is entertained that, in the
latter case, the common salt and sulphuric acid were not perfectly
dry.—_Bull. Univ._
14. _Crystallization of Phosphorous_.—By the fusion and careful
refrigeration of a large quantity of phosphorus, M. Frantween has
obtained very fine crystals of an octoedral form, and as large in
size as a cherry-stone.
15. _Solutions of Phosphorus in Oils_.—The solutions of phosphorus
in fixed oils are so luminous as often to be resorted to for the
exhibition of this peculiar property of phosphorus; but M. Walcker
has remarked, that the power which they ordinarily possess is
instantaneously destroyed by the addition of small quantities only of
certain other substances, as the essential oils. The rectified oils
of turpentine and amber, the oils of rosemary, bergamotte, lemon,
camomile, angelica root, juniper berries, and parsley seed, [p207]
the oil obtained by the distillation of the nutmeg, all produce this
effect when their quantity is not more than one-fiftieth part of the
luminous oily solution of phosphorus. The same effect is produced by
adding about a fifth of the oils of anniseed, cajeput, lavender, rue,
sassafras, fern, cascarilla, mint, orange flowers, fennel, valerian,
cherry laurel, or bitter almonds, or balsam of copaiba; but the oil
of cinnamon, rectified petroleum, balsam of Peru, and camphor, have
no such effect.—_Annal. der Phys._ 1826, p. 125.
16. _On the Inflammation of Powder when struck by Brass, &c._—Iron
has been excluded from powder-works as subject to cause sparks by a
blow, and brass and copper have been recommended in its place. M. le
Col. Aubert has remarked, that brass on brass can inflame powder, and
has made experiments on the subject before a committee, the result of
which is as follows:—Inflammation of the powder takes place when the
blow is given by iron against iron; iron against brass; brass against
brass; iron against marble; lead against lead, or against wood,
when the blow is produced by a leaden ball shot from a fire-arm. As
yet the powder has not been inflamed by the blow of an iron hammer
against lead or wood.—_Bull. de la Soc. d’Encouragement;_ _Bull.
Univ._
17. _Cementation of Iron by Cast Iron_.—Pure iron, when surrounded
by, and in contact with, cast iron turnings, and heated, is
carbonised very rapidly, so as to harden, to temper, and, in fact,
to exhibit all the properties of steel. M. Gautier finds this a very
advantageous process in numerous cases, especially where the articles
to be case-hardened, or converted into steel, are small, as iron
wire, or wire gauze. The temperature required is not so high as that
necessary in the ordinary process of cementation, and the pieces to
be carbonised are not injured in form. The kind of cast iron used
should be the gray metal, and the more minutely it is divided the
more rapid and complete is the operation. By covering the mass of
cast metal, in which the iron to be carbonised is enveloped, with
sand, oxidation, from contact of the air, is prevented, and the cast
metal may be used many times. Plumbago experimented with in the same
manner does not produce the effect.—_Jour. de Pharmacie_, 1827, p. 18.
18. _On the Preparation of Ferro-prussiate of Potash, by_ M.
Gautier.—Numerous investigations induced M. Gautier to conclude,
that, i. When animal matter is calcined alone it yields but little
cyanogen. ii. That when mixed with potash it gives more, but the
cyanuret is not ferruretted. iii. That ammonia is then produced in
large quantity. iv. That the substitution of nitre for potash, and
the addition of iron or scales of iron, augmented the production of
cyanogen, and gave a ferro-prussiate. The following is the process
of manufacture to which M. Gautier has ultimately arrived, [p208]
and which he has practised for some years. The proportions of the
materials are—
Blood, considered as in the dry state, 3 parts
Nitre 1 part
Iron scales 1/50 of the blood employed.
The blood is first to be coagulated in a large copper cauldron, and
the serum being separated by means of a press, the coagulum is to be
returned to the cauldron with the nitre and iron. The quantity of
water contained in the blood is sufficient to liquify the salt, so as
to allow of an uniform mixture being effected. The mixture is then
removed, and exposed in an airy situation to dry, the putrefaction
of the blood being prevented by the nitre. When the desiccation is
complete, the mixture is charged into cast iron cylinders, which are
fixed in a reverberatory furnace, and in all things resemble those
used in the preparation of animal charcoal. These are to be raised to
a brown red heat, until no more vapour is disengaged, and then left
until nearly cold, after which the contents are to be withdrawn and
put into a wooden vat, with twelve or fifteen times their weight of
water, for an hour. The fluid is then to be filtered through a cloth,
and evaporated until of 32° of Beaué (specific gravity 1.284.) Being
then left to cool, a large quantity of well-crystallized bi-carbonate
of potash is obtained. M. Gautier says he has not, as yet, been
able to explain how it is that this bi-carbonate has been formed
at so high a temperature; a portion also appears to be decomposed
during the evaporation of the solution, which, at first but slightly
alkaline, becomes sensibly so by a prolonged evaporation.
As the same product is not obtained when potash is used in place of
nitre, it is probable that the elements of the nitric acid perform a
particular part in the operation.
The solution which has given the crystals of carbonate of potash
contains a little carbonate of potash, and much ferro-prussiate of
potash. It is to be concentrated to 34° (specific gravity 1.306), and
placed in wooden vessels lined with lead. In the course of some days
a greenish crystalline mass is obtained, which being redissolved in a
fresh quantity of pure water, and evaporated to 32° or 33° (specific
gravity 1.295), is to be recrystallized.
Sometimes, when using potash, M. Gautier has mixed nitre with it, and
has always obtained a richer product than when potash alone had been
employed.—_Jour. de Phar._ 1827, p. 11.
19. _Sulphocyanide of Potassium in Saliva_.—MM. Tiedemann and Gmelin
have observed the existence of this peculiar compound in saliva, in
two cases; the one when the fluid was secreted during smoking, and
the other when no such stimulus was applied.—_Ann. de Chimie_, xxxv.
266.
20. _Decomposition of Sulphate of Copper by Tartaric Acid_.—M. [p209]
Planche has observed, that when sulphate of copper is dissolved in
wine vinegar, for the purpose of preparing a corrosive liquid to be
applied to corns on the feet, that the tartaric acid present in the
vinegar displaces the sulphuric acid from a part of the salt, and an
insoluble acid tartrate of copper is produced.
21. _Separation of Arsenic from Nickel or Cobalt_.—The following
process by M. Woehler seems among the best of those intended for
freeing nickel or cobalt from arsenic in the dry way. It is founded
upon the circumstances that many alloys, when heated with sulphuret
of potash, become changed into a mixture of sulphurets, and that
sulphuret of arsenic is very soluble in sulphuret of potash. One
part of kupfernickle, fused and reduced to fine powder, is to be
mixed with 3 parts of carbonate of potash, and 3 parts of sulphur,
in a covered Hessian crucible. The heat is to be gradually raised to
redness, and until the mass is just entering into fusion, and by no
means so highly as to fuse the sulphuret of nickel which is formed.
When cold, water is to be added, which will dissolve the sulphuret
of potash, and leave a yellow crystalline powder, which is sulphuret
of nickel, retaining, perhaps, a little copper or cobalt, but no
arsenic, if the operation has been well performed. When, however, the
object is to have the nickel perfectly pure, it should be fused a
second time with sulphur and potash.
The method of freeing cobalt from arsenic, is the same as for
nickel; but it is then necessary to perform the operation a second
time. The cobalt (that of Tunaberg) has never been perfectly freed
from arsenic by one operation, but has never retained any after the
second.—_Archiv für Bergbau_, 1826, p. 186.
22. _Compounds of Gold_.—According to late experiments of Dr.
Thomson, peroxide of gold consists of
1 atom gold 25
3 " oxygen 3
---
28
and is consequently a teroxide. Muriate of gold consists of
2 atoms muriatic acid 9.25
1 " per oxide of gold 28.
5 " water 5.625
------
42.875
_Edin. Journal_, p. 182.
23. _Chemical Researches relative to certain Ancient Substances_.—M.
Vauquelin has analyzed, i. A poignard blade formed of copper only;
ii. A mirror, which was found to consist of 85 parts of copper, 14
of tin, and 1 of iron per cent.; iii. A blue colour found in a tomb:
[p210] it was composed of silica 70 parts; lime 9; oxide of copper
15; oxide of iron 1; soda mixed with potash 4. A blue identical with
this, both in colour and composition, was found in the bottom of a
furnace in which copper had been fused at Romilly.
M. D’Arcet has examined a bone from the fore part of an ox, which had
been placed as an offering to the divinity in an Egyptian tomb, and
found that it contained as much gelatine as recent bone, although
rather less is obtained by muriatic acid, (20 per cent. instead of
27) because of a deterioration of the bone. When burnt, it gave an
animal black as deep in colour as that from recent bone.
M. Le Baillif has examined some grains of corn, which were so well
preserved, that when put into boiling water iodine produced the
blue colour dependent upon starch. He also made some experiments on
a gummy substance, and on two cords from a musical instrument; the
latter were of animal substance.
M. Raspail examined some grain which was supposed to be wheat, but
found it to be torrified barley; it was covered with a substance
communicated probably by the oil and incense with which the grains
were bathed when consecrated. Similar grains were obtained by
roasting common barley.
The account of most of these researches is given in the Catalogue
raisonné et historique des Antiquités découvertes en Egypte, by M.
Passalacqua.—_Bull. Univ._ A. vii. 264.
24. _On the Bitter Substance produced by the action of Nitric Acid on
Indigo, Silk, and Aloes_, _by_ M. Just Liebeg.—The process by which
M. Liebeg obtains a pure and uniform substance from the action of
nitric acid on indigo, is as follows:—A portion of the best indigo
is to be broken into small fragments, and moderately heated with
eight or ten times its weight of nitric acid of moderate strength.
It will dissolve, evolving an abundance of nitrous vapours and
swelling up in the vessel. After the scum has fallen, the liquid is
to be boiled, and nitric acid added, whilst any disengagement of red
vapours is occasioned by it. When the liquid has become cold, a large
quantity of semi-transparent yellow crystals will be formed, and if
the operation has been well conducted, no artificial tannin or resin
will be obtained. The crystals are to be washed with cold water, and
then boiled in water sufficient to dissolve them. If any oily drops
of tannin form on the surface of the solution, they must be carefully
removed by touching them with filtering paper. Then filtering the
fluid, and allowing it to cool, yellow brilliant crystalline plates
will be obtained, which will not lose their lustre by washing.
To obtain the substance perfectly pure, the crystals must be
re-dissolved in boiling water, and neutralized by carbonate of
potash. Upon cooling, a salt of potash will crystallize, which should
be purified by repeated crystallizations.
On mixing the first mother liquor with water, a considerable brown
precipitate will be obtained, which being dissolved in boiling
[p211] water, and neutralized by carbonate of potash, will furnish
a large quantity of the potash salt. All the potash salt obtained
in these operations is to be re-dissolved in boiling water, and
nitric, muriatic, or sulphuric acid added; as the solution cools, the
peculiar substance will be observed to form very brilliant plates of
a clear yellow colour, generally in equilateral triangular forms.
Sometimes crystals are not formed after the action of the nitric acid
on the indigo, in which case the liquor must be evaporated, and water
added, when the substance will precipitate, and must be purified
as already described. Four parts of indigo yield one of the pure
substance.
When the substance is heated, it fuses, and is volatilized without
decomposition; when subjected to a sudden strong heat, it inflames
without explosion, its vapours burning with a yellow flame, and a
carbonaceous residue remaining. It is but little soluble in cold
water, but much more in boiling water; the solution has a bright
yellow colour, reddens litmus, has an extremely bitter taste, and
acts like a strong acid on metallic oxides, dissolving them, and
forming peculiar crystallizable salts.—Ether and alcohol dissolve the
substance readily.
When fused in chlorine or with iodine, it is not decomposed, nor does
solution of chlorine affect it. Cold sulphuric acid has no action
on it; when hot, it dissolves it, but water separates the substance
without alteration. Boiling muriatic acid does not affect it, and
nitro-muriatic acid only with great difficulty.
These results show that no nitric acid is present in the substance,
and other experiments prove that no oxide of nitrogen exists in it;
it contains no oxalic or other organic acid, for when its salt is
boiled with chloride of gold, the latter is not reduced.
When heated to redness with oxide of copper, it gave a mixture of
nitrogen and carbonic acid, in the exact proportion of 1 volume of
the former, to 5 of the latter. This was a constant result, and in no
case was any sulphuric or muriatic acid left in the copper. 0.0625
grammes of the substance thus decomposed, gave 45 cubic centimeters
of the mixed gases, estimated at 0° C. (32° F.) and the pressure of
28 inches of mercury, according to which the acid would be composed
of carbon 32.392; nitrogen 15.2144; oxygen 52.3936 per cent. From the
mean of several experiments, it appeared that the following might
represent the composition correctly.—
12-1/2 atoms of carbon 93.75 or 31.5128
2-1/2 " azote 43.75 " 14.7060
16 " oxygen 160.00 " 53.7812
------- --------
297.5 100.
100 parts of the acid neutralize a quantity of base equivalent to
3.26 of oxygen, which is to the oxygen of the acid, as 1:16; the
equivalent number of the acid derived from the analysis of the [p212]
barytic salt was 306.3; by adding only 1/4 per cent. to the quantity
of baryta obtained in the experiment, 297.5, or the number expressed
by the above formula, would be obtained.
When a salt of potash or baryta was decomposed by oxide of copper and
heat, the quantity of carbonic acid produced was a little short of
five times the quantity of nitrogen; but, upon adding that retained
by the alkali or earth, the proportion became exactly the same as in
the former cases.
_Welter’s bitter principle_ was prepared by acting on silk with ten
or twelve times its weight of nitric acid. The liquid, slightly
coloured at first, acquired a deep yellow upon adding water. It was
neutralized by carbonate of potash whilst hot, and left to cool, and
the salt of potash thus obtained, decomposed by muriatic, nitric, or
sulphuric acid. This acid, crystallized like that from indigo, formed
the same salts, and was composed in the same manner. Silk furnishes
much less of the substance than indigo. Dr. Liebeg has called this
substance _carbazotic acid_. The most important salts formed by it
have the following properties:—
_Carbazotate of Potash_—crystallizes in long yellow quadrilateral
needles, semi-transparent and very brilliant; it dissolves in
260 parts of water at 59° F., and in much less, boiling water: a
saturated boiling solution becomes a yellow mass of needles, from
which scarcely any fluid will run. Strong acids decompose it;
yet when an alcoholic solution of carbazotic acid is added to a
solution of nitre, crystallized carbazotate of potash, after some
time, precipitates.—Alcohol does not dissolve it. When a little
is gradually heated in a glass tube, it first fuses, and then
suddenly explodes, breaking the tube to atoms; traces of charcoal
are observed on the fragments. This salt precipitates a solution
of the protonitrate of mercury, but not salts, containing the
peroxide, or those of copper, lead, cobalt, iron, lime, baryta,
strontia, or magnesia. The slight solubility of this salt supplies
an easy method of testing and separating potash in a fluid. Even
the potash in tincture of litmus may be discovered by it; for, on
adding a few drops of carbazotic acid, dissolved in alcohol, to
infusion of litmus, crystals of the salt gradually separated. The
saturated solution of the salt at 50° F., is not troubled by muriate
of platina. The salt contains no water of crystallization. It was
analyzed by converting a portion of it into chloride of potassium by
muriatic acid: its composition is,—
Carbazotic acid 83.79
Potash 16.21
------
100.00
_Carbazotate of Soda_—crystallizes in fine silky yellow needles,
having the general properties of the salt of potash, but soluble in
from 20 to 24 parts of water, at 59° F.
_Carbazotate of Ammonia_ forms very long, flattened, brilliant,
[p213] yellow crystals, very soluble in water. Heated carefully in
a glass tube, it fuses, and is volatilized without decomposition;
heated suddenly, it inflames without explosion, and leaves much
carbonaceous residue.
_Carbazotate of Baryta_, obtained by heating carbonate of baryta, and
carbazotic acid with water. It crystallizes in quadrangular prisms of
a deep colour, and dissolves easily in water. When heated, it fuses,
and is decomposed with very powerful explosion, producing a vivid
yellow flame. The explosion is as powerful as that of fulminating
silver; a solution of chloride of potassium to which carbazotate of
baryta has been added, produces a precipitate of the potash salt,
and not more than 1-1/2 per cent. of potash remains in solution. 100
parts of the crystallized salt contain,—
Carbazotic acid 69.16 oxygen of the acid 16
Baryta 21.60 " earth 1
Water 9.24 " water 8
-------
100.00
_Carbazotate of Lime_, obtained like the salt of baryta, forms
flattened quadrangular prisms, very soluble in water, and detonating
like the salt of potash.
_Carbazotate of Magnesia_ forms very long indistinct needles, of a
clear yellow colour; is very soluble, and detonates violently.
_Carbazotate of Copper_, prepared by decomposing sulphate of
copper by carbazotate of baryta: it crystallizes with difficulty,
the crystals being of a fine green colour; it is deliquescent;
when heated, it is decomposed without explosion, and even without
inflammation.
_Carbazotate of Silver_.—Carbazotic acid readily dissolves oxide of
silver, when heated with it and water; and the solution, gradually
evaporated, yields starry groups of fine acicular crystals of the
colour and lustre of gold; the salt dissolves readily in water; when
heated to a certain degree, it does not detonate, but fuses like
gunpowder.
_Proto-Carbazotate of Mercury_, obtained in small yellow triangular
crystals, by mixing boiling solutions of the carbazotate of potash or
soda, and proto-nitrate of mercury. It requires more than 1200 parts
of water for its solution: for its perfect purification, it should
be heated with a solution of chloride of potassium, the insoluble
portion separated whilst the liquid is lost, and the peculiar salt
allowed to deposit as the temperature falls. When heated, it behaves
like the salt of silver.
All these salts detonate much more powerfully when heated in close
vessels, than when heated in the air; and it was a curious thing to
observe, that those with bases yielding oxygen most readily, were
those which exploded with least force. By heating some of the salts
previously mixed with chloride of potassium, &c., to retard the
action, it appeared that no carbonic oxide, but only carbonic [p214]
acid and azote were evolved during their decomposition by heat.