be to form a common green chamelion, to convert it into red chamelion
by sulphuric acid, and to evaporate the solution, which will give
a residue consisting of sulphate and manganesate of potash. This
mixture, acted upon by concentrated sulphuric acid, produces the
solution of manganesic acid, into which the common salt is to be
thrown in small pieces, until the vapours which rise are colourless;
the latter effect is a sign that all the manganesic acid is
decomposed, and that muriatic acid only is produced.
An analogous compound is formed when a fluoride is used in place of
the common salt. But all attempts as yet made to collect a sufficient
quantity for examination have failed; the chloride, on the contrary,
is easily formed and examined, although it is not so easy to preserve
it.—_Annales de Chimie_, xxxvi. 81. [p476]
FOOTNOTE:
[132] Query, what is a permanent gas?—ED.
20. _Preparation of pure Oxide of Zinc, by_ M. Hermann.—It is by no
means easy to obtain this substance perfectly pure; the following
is M. Hermann’s process: Oxide of zinc, or metallic zinc, is to
be dissolved in excess of sulphuric acid, and the solution being
filtered, sulphuretted hydrogen is to be passed through, so long
as a brown or yellow precipitate is formed. Cadmium, lead, or
copper, being thus separated, and the solution filtered, it is to be
treated with solution of the chloride of lime, (bleaching powder,)
by which the iron and manganese will be separated. The solution,
again filtered, is then to be crystallized in porcelain vessels, by
which sulphate of lime is rejected, and a mother liquor separated,
which usually contains cobalt and nickel. The crystals of sulphate
of zinc are to be dissolved in as small a quantity of cold water as
possible, and the sulphate of lime filtered out; then the solution,
being rendered more dilute, is to be decomposed by carbonate of
soda in slight excess, and the precipitate well washed, dried, and
heated to redness: it is then a perfectly pure and beautifully white
oxide.—_Bull. Univ._ A. viii. 263.
21. _Deuto-Sulphuret of Cobalt_.—Mix finely divided oxide of
cobalt with three times its weight of sulphur, and heat to very
dull redness, until no more sulphur sublimes. The deuto-sulphuret
consists of 100 cobalt + 109 sulphur; it is black; is reduced to gray
proto-sulphuret by a strong heat.—_Sitterberg_.
22. _Separation of Bismuth from Mercury by Potassium_.—M. Serullas
has pointed a striking instance of the separation of bismuth from
mercury. He says a twelve hundred thousandth, and even less of
bismuth, when dissolved in mercury, may be separated and rendered
visible by the addition of a certain quantity of the amalgam of
potassium and a little water. A black powder is observed to rise from
the substance of the metal, and is a mixture of bismuth and mercury
in a very divided state; it rises to the surface or adheres to the
vessels.
Copper, lead, tin, and silver, are equally separated, but not so
promptly, or so evidently to the eye as bismuth; for they are not
associated with divided mercury, at the time of their separation,
like the latter: with bismuth a mere atom is rendered visible, and M.
Serullas thinks that chemistry does not present a more delicate test
than the amalgam of potassium for bismuth in mercury.—_Annales de
Chimie_, xxxiv. 195.
23. _Sulphuret of Arsenic proportionate in Composition to Arsenic
Acid_.—M. Pfaff acted upon arsenious acid by nitro-muriatic acid,
and obtained a pure arsenic acid soluble in water, and deliquescent
in the air. This, dissolved in 40 parts of water, had a current of
sulphuretted hydrogen passed through it, which instantly produced a
yellow orange precipitate of a pulverulent form, continuing identical
in composition, until no further precipitate was [p477] occasioned.
The fluid was then perfectly free from arsenic. The precipitate was
pure sulphuret of arsenic, soluble in ammonia when slightly heated,
and composed of equal parts of sulphur and the metal.
M. Pfaff further says that arsenic acid may be separated from its
combinations with bases, by dissolving the arseniates in nitric acid,
and passing sulphuretted hydrogen through the solution; an abundant
precipitate of sulphuret of arsenic is formed, containing no trace of
the base of the arseniate decomposed.—_Bull. Univ._ A. viii. 256.
24. _New Double Chromates_.—Mr. Stokes has obtained several new
salts, by mixing chromate of potash with metallic sulphates. Chromate
of potash, mixed with sulphate of zinc, gave a precipitate of
chromate of zinc; and the mother liquor, by concentration, yielded
certain yellow crystals in the form of a flat rhombic prism, which
Dr. Thomson had mistaken for impure sulphate of zinc, but which Mr.
Stokes recognised as a new compound: 50 grains gave 18.33 sulphuric
acid; 0.18 chromic acid; 9.87 oxide of zinc; 8.91 potash; 12.6 water:
0.11 loss.
Chromate of potash and sulphate of nickel were mixed in atomic
proportions, and the solutions heated; after the chromate of nickel
was separated, they were evaporated to dryness. The residuum,
digested in water, was filtered, and the deep red solution obtained
upon cooling, yielded grass green crystals in the form of oblique
rhombic prisms; 50 grains of these, when analysed, gave 12.26
sulphuric acid; 0.978 chromic acid; 8.2 oxide of nickel; 9.862
potash; 12.7 water.
A similar salt may be obtained by mixing chromate of potash and
sulphate of copper. It is of a light green colour, and has precisely
the same form as the salts already described. In every case
crystals of bichromate of potash were produced in the second crop
crystals.—_Phil. Mag. N. S._ ii. 427.
25. _Dobereiner’s finely divided Platina_.—The following is M.
Dobereiner’s process for obtaining finely divided platina, fit
for the performance of the experiment which he first made on the
combination of oxygen and hydrogen, at common temperatures. Mix
muriate of platina with a solution of neutral tartrate of soda in
a glass tube, half or three-quarters of an inch in diameter, and
twenty or thirty inches in length, and apply heat until the fluid
becomes slightly turbid; afterwards expose it for several days to
the sun’s rays. The greater part of the platina will separate from
the solution, and be deposited in minute laminæ, of a greyish black
colour on the sides of the glass; the tube and its contents are
to be put into a glass vessel containing water, and it is to be
filled with hydrogen gas; the platina becomes almost immediately
white and shining like silver, and may then be readily detached
from the glass. During the reduction of the platina the tartaric
acid is partly converted into carbonic and formic acids. “As the
inflammation [p478] of the hydrogen,” it is said, “is caused by
abstracting a portion of the caloric from the oxygen, effected by
the platina, the smaller the laminæ of the metal are, the more
readily is the incandescence produced.” Spongy platina for the lamps
for instantaneous light, is prepared of great power, by moistening
the muriate of ammonia and platina with a concentrated solution of
ammonia; the paste formed is to be heated to redness in an earthen or
platina crucible.—_Hensman’s Repertoire—Phil. Mag. N. S._ ii. 388.
26. _New Metals_.—Professor Osann, of Dorpat, is said to have
discovered three new metals in the crude platina, obtained from the
Uralian mountains. One, which has occurred only in one specimen of
the ore, resembles osmium in some of its compounds. The second forms
white acicular crystals from a nitro-muriatic acid solution; these,
when heated, being softened and reduced. The third is insoluble in
nitro-muriatic acid, and, by a particular process yields a dark
green-coloured oxide. The account as yet given of these substances is
not precise enough to allow of any judgment respecting their claim to
the character of new metals.
27. _Analysis of Porcelain, Pottery, &c., by_ M.
Berthier.—Earthenware manufactures are divided by M. Berthier
into three kinds, those of 1. Porcelain; of 2. Pottery; and of 3.
Crucibles, Bricks, &c. The following is the composition of certain
porcelains:
PORCELAIN.
Sèvres. English. Piedmont. Tournay.
(i.) (ii.) (iii.) (iv.)
Silica 0.596 0.770 0.600 0.753
Alumina 0.350 0.086 0.090 0.082
Potash 0.018 .. .. 0.059
Soda .. .. .. 0.059
Lime 0.024 0.012 0.016 0.100
Magnesia 0.070 0.152 ..
Water 0.008 0.056 0.136 0.006
----- ----- ----- -----
0.996 0.994 0.994 1.000
(i.) Sèvres service—Paste strongly heated. It is formed from 0.63
washed kaolin of Limoges; 0.105 quartz sand; 0.052 Bougeval chalk;
0.21 of the fine sand obtained from kaolin by washing, and which is
a mixture of quartz and felspar. The glaze of this ware is made of a
rock composed of quartz and feldspar. When reduced to a fine powder,
it is found to be composed of silica .730, alumine 162, potash 84,
water 6: it fuses into a perfectly transparent and colourless glass.
(ii.) Worcester porcelain—Paste taken from the workshops, unbaked.
(iii.) Porcelain of Piedmont—Paste dried. The base of this
manufacture is the _magnesite_ of Baldissero.
(iv.) Porcelain of Tournay—Clay, chalk, and soda enter into its
composition. It is very fusible, but not very fragile. [p479]
POTTERY.
Nevers. Paris. Gergovia.
(i.) (ii.) (iii.)
Silica 0.572 0.541 0.544
Alumina 0.124 0.127 0.220
Lime 0.226 0.063 0.064
Oxide of Iron 0.066 0.070 0.098
Magnesia .. 0.024 0.038
Water .. 0.173 0.020
----- ----- -----
0.988 0.998 0.984
(i.) Earthenware of Nevers—Paste of a pale red. Made of a marle
occurring close to the town; the glaze is a white enamel, containing
both tin and lead.
(ii.) Paste of the brown earthenware made by M. Husson at Paris. The
biscuit is red, but is covered by a brown glaze, coloured by oxide of
manganese.
(iii.) Red earthenware resembling the Etruscan, and found in the
ruins of Gergovia near Clermont.
CRUCIBLES, &C.
St.
Hessian. Paris. English. Etienne.
(i.) (ii.) (iii.) (iv.)
Silica 0.709 0.646 0.637 0.652
Alumina 0.248 0.344 0.207 0.250
Oxide of Iron 0.038 0.010 0.040 0.072
Magnesia trace .. .. trace
Water .. .. 0.103 ..
----- ----- ----- -----
0.995 1.000 0.987 0.974
Le
Nemours. Bohemia. Creusot.
(v.) (vi.) (vii.)
Silica 0.674 0.680 0.680
Alumina 0.320 0.290 0.280
Oxide of Iron 0.008 0.022 0.020
Magnesia trace 0.005 trace
Water .. .. 0.010
----- ----- -----
1.002 0.997 0.990
(i.) Hessian crucibles—formed of a clay very aluminous, with which
siliceous sand is mixed. They sustain rapid changes of temperature
without fracture, but cannot retain fused litharge very long
together, and have too coarse a grain for many purposes.
(ii.) Paris crucibles, manufactured by Beaufaye—they are made from
the clay of Andennes, near Namur; part of the material being baked
and coarsely powdered, and the rest in its natural state: no sand
is mixed with it, and the inner surface of the vessels is finished
with a thin coat of the unbaked material. They are said to be more
refractory than the Hessian vessels, not more liable to fly by change
of temperature, and more retentive of litharge.
(iii.) Fragment of an unbaked crucible prepared for an English
cast-steel work.
(iv.) Paste with which the crucibles are made for the steel works of
Berardière, near St. Etienne.
(v.) Fragment of a used crucible from the glass works of Bagneaux,
near Nemours; it had been made from the clay of Forges (Seine
Inférieure).
(vi.) A used crucible from a Bohemian glass-house.
(vii.) Bricks with which the blast furnaces at Creusot are [p480]
constructed; they are made of a mixture of baked and unbaked
clay.—_Annales de Chimie_, i. 469.
28. _On the Composition of simple Alimentary Substances, by_ Dr.
Prout.—It is well known that Dr. Prout has of late years devoted that
portion of his attention which he gives to chemistry, exclusively
to the consideration of organized substances, with the important
object of making the knowledge he might obtain subservient to the
study of physiology and pathology; and during the last session of the
Royal Society, a paper by this philosopher was read, containing many
important and apparently accurate results relative to the particular
subjects which he has pursued; some account of which we are desirous
of giving in this place.
Dr. Prout’s first object was to devise, if possible, an
unexceptionable mode of determining the proportions of the three or
four principles, which, with few exceptions, form organic bodies;
and after numerous trials, he adopted a method founded upon the
following well known principles. When an organic product, containing
three elements, hydrogen, carbon, and oxygen, is burnt in oxygen
gas, one of three things must happen: i. The original bulk of oxygen
gas may remain the same, in which case the hydrogen and oxygen in
the substance must exist in it in the same proportions in which
they exist in water; or, ii. The original bulk of the oxygen may be
increased, in which case the oxygen must exist in the substance in
a greater proportion than it exists in water; or, iii. The original
bulk of the oxygen gas may be diminished; in which case the hydrogen
must predominate. Hence it is obvious, that, in the first of these
cases, the composition of a substance may be determined, by simply
ascertaining the quantity of carbonic acid gas yielded by a known
quantity of it; while, in the other two, the same can be readily
ascertained by means of the same data, and by noting the excess or
diminution of the original bulk of the oxygen gas employed.
The apparatus consists of two inverted glass syphons which act the
part of gasometers; these are connected when required, by a small
green glass tube, in which the substance is to be decomposed and
burnt: the syphons are very carefully gradated; so that the quantity
of gas in them can be accurately estimated; and are supplied with
cocks both above and below, so that they can be filled with mercury,
the mercury drawn off and gas introduced, the gas transferred through
the green glass tube, or the contents retained in an undisturbed
state, with the utmost readiness and ease. The substance to be
decomposed, may be put into a platina tray, and introduced alone
into the green glass tube, and being there heated by a spirit lamp,
be burnt in the gas passing over it; or it may be mixed with pure
siliceous sand; or, what is most generally preferable, be mixed with
peroxide of copper, which is always left, in consequence of the
excess of oxygen gas used, in the state in which it was introduced.
After the experiment the volume of gas is easily [p481] corrected
for pressure, and if necessary for temperature, and the carbonic acid
ascertained by the removal and analysis of a portion. No correction
is required for moisture, the gas always being used saturated with
water.
Dr. Prout considers the principal alimentary substances as reducible
to three great classes, the _saccharine_, the _oily_, and the
_albuminous_; and his paper relates to the first of these. This, with
certain exceptions, includes the substances in which, according to
MM. Gay Lussac and Thenard, the oxygen and hydrogen are in the same
proportion as in water. Such substances are principally derived from
the vegetable kingdom, and being at the same time _alimentary_, Dr.
Prout uses the terms _saccharine principle_ and _vegetable aliment_
as synonymous.
The following tables show some of Dr. Prout’s results with several
substances, extreme care having been taken in every case to obtain
the bodies pure, and new processes often resorted to for that purpose.
SUGAR.
Carbon. Water.
Pure sugar-candy 42.85 57.15
Impure sugar-candy 41.5 to 42.5 58.5 to 57.5
East India sugar-candy 41.9 58.1
English refined sugar 41.5 to 42.5 58.5 to 57.5
East India refined sugar 42.2 57.8
Maple sugar 42.1 57.9
Beet root sugar 42.1 57.9
East India moist sugar 40.88 59.12
Sugar of diabetic urine 36. to 40? 64. to 60?
Sugar of Narbonne honey 36.36 63.63
Sugar from starch 36.2 63.8
AMYLACEOUS PRINCIPLE.
Carbon. Water.
Fine wheat starch 37.5 62.5
" dried (i.) 42.8 57.2
" highly dried (ii.) 44 56
Arrow root 36.4 63.6
" dried (iii.) 42.8 57.2
" highly dried (iv.) 44.4 55.6
(i.) Dried between 200° and 212° for twenty hours, lost 12.5 per cent.
(ii.) Part of the former, dried between 300° and 350° for six hours,
lost 2.3 per cent.
(iii.) Dried as (i.), lost 15 percent.
(iv.) Part of the last, heated to 212° for six hours longer, lost 3.2
per cent. more.
LIGNIN, OR WOODY FIBRE,
Obtained by rasping wood, and then pulverising it in a mortar;
boiling the impalpable powder in water till nothing more was [p482]
removed, then in alcohol; again in water, and dried in the air till
they ceased to lose weight.
Carbon. Water.
From box 42.7 57.3
" dried (i.) 50. 50.
From willow 42.6 57.4
" dried (i.) 49.8 50.2
(i.) Dried at 212° for six hours, afterwards between 300° and 350°
for six hours. That from box lost 14.6, that from willow 14.4 per
cent.
Acetic acid 47.05 52.95
Sugar of milk 40. 60.
Manna sugar 38.7 61.3
Gum arabic 36.3 63.7
" dried (i.) 41.4 58.6
(i.) Dried between 200° and 212° for twenty hours, lost 12.4 per
cent. The same gum further heated to between 300° and 350° for six
hours, lost only 2.6 per cent., and had become deep brown.
Vegetable Acids. Carbon. Water. Oxygen.
Oxalic acid 19.04 42.85 38.11
Citric acid 34.28 42.85 22.87
Tartaric acid 32.00 36.00 32.00
Malic acid 40.68 45.76 13.56
Saclactic acid 33.33 44.44 22.22
29. _Preparation of Sulphate of Quinia and Kinic Acid, without the
use of Alcohol_.—The following is the process of MM. Henry and
Plisson: About two pounds of bark are to be coarsely powdered and
boiled with water, acidulated with sulphuric acid in the usual
manner. When the hot liquors are cleared, recently prepared and moist
hydrate of lead is to be added until the fluid is neutral, and has
acquired a faint yellow colour; this must be done carefully, lest too
much hydrate of lead be added. As the decoloration of the decoction
is necessary, the liquid, if it remains turbid until the next
morning, must have a little more hydrate added and be re-filtered,
but the operation is rarely subject to this inconvenience, being
usually finished in a few hours. The yellow liquid contains a little
kinate of lead, much kinate of lime, kinate of quinia or cinchonia,
a little colouring matter, and traces of other substances. The
washed deposite consists of colouring matter, combined with oxide of
lead, sulphate of lead, and a portion of free quinia; contains no
sub-kinate of lead.
The lead, dissolved in the fluid, is to be separated by a few drops
of sulphuric acid, or a small current of sulphuretted hydrogen, and
the filtered liquid is to be precipitated by adding caustic lime,
previously mixed into a thin paste with water, until the earth is
in very slight excess; in this manner the quinia is precipitated.
The addition of sulphuric acid readily converts this quinia into
sulphate, [p483] which may be obtained in very white and silky
crystals. The fluid left after the separation of the quinia,
contains a kinate of lime almost pure. Being evaporated until of
the consistence of syrup, it readily crystallizes in a mass, which
may then be purified by recrystallization. The kinate of lime may
be precipitated by means of alcohol, and then be crystallized after
solution in water or diluted alcohol; or, by adding oxalic acid drop
by drop, according to the directions of M. Vauquelin, the lime may
be separated and kinic acid obtained. Two thirds of the quinia or
cinchonia in a specimen of bark may be thus separated, and with such
facility as to offer a ready test of the presence of these alkalies
in any wood or bark submitted to examination.—_Ann. de Chimie_,
xxxv., 166.
30. _Pure Narcotine prepared_.—The following process is that
practised by Mr. Carpenter. Digest one ounce of coarsely powdered
opium in one pint of ether for ten days, frequently submitting it
to ebullition in a water bath; separate the ether and add fresh
portions until the opium is exhausted; place the ethereal solution in
a wide-mouthed bottle, and, covering the mouth with bibulous paper,
allow the ether to evaporate spontaneously, but slowly; as the fluid
diminishes, it leaves the sides of the bottle coated with crystals
of narcotine; as the solution becomes more dense, the crystals
enlarge and accumulate, and the bottom of the vessel is covered with
large transparent crystals, accompanied with a brown viscid liquor
and extract, which contains an acid resin, caoutchouc, &c. Separate
these substances and wash the crystals in successive portions of cold
ether to remove the extract; then dissolve them in warm ether, and
evaporate slowly as before; beautiful snow white crystals of pure
narcotine will be obtained: those on the sides of the vessel assume
plumose and arborescent forms; they enlarge as the solution becomes
more concentrated, and the bottom of the bottle becomes covered with
pure narcotine, assuming the rhomboidal prismatic form with some
modifications of maccled crystals. The crystals towards the bottom
are transparent, but the most minute at the top are opaque and snow
white. By picking out the largest and most regular crystals, again
dissolving and evaporating, and repeating the same process, each
time selecting the largest and best crystals, some were obtained the
eighth of an inch in diameter, and still larger might be produced by
similar operations.—_Silliman’s Jour._, xiii. 27.
31. _Uncertain Nature of Jalapia_.—Relative to Mr. Hume’s supposed
vegeto-alkali _Jalapia_, M. Pelletier says it is nothing more than
a mixture of sulphate of lime and sulphate of ammonia.—_Jour. de
Pharmacie_.
32. _Preparation of pure Mellitic Acid, by_ M. Wöhler.—Concentrated
solution of carbonate of ammonia was poured upon finely pulverised
mellite, and boiled until the excess of ammonia was [p484]
dissipated; the solution was filtered and left to crystallize. The
pure crystals, being dissolved in water, were precipitated by acetate
of lead, and the mellitate of lead, after being well washed was
decomposed by sulphuretted hydrogen; being filtered, the solution was
evaporated to dryness, during which the mellitic acid precipitated
as a white powder; being dissolved in cold alcohol, and left to
evaporate spontaneously, the acid was obtained in acicular crystals.
In this state it is very acid, unaltered by air, very soluble in
water and alcohol, and sustains a considerable heat without change;
it does not fuze, but ultimately sublimes, though probably not
without decomposition. When boiled for a considerable time with
alcohol, it undergoes a peculiar change, and occasions the production
of a new acid substance, resembling the benzoic acid.
33. _On a New Acid existing in Iceland Moss_.—The reddish purple
colour which is produced by adding a decoction of Iceland moss to
per-salts of iron, has been attributed to the presence of gallic
acid, but is found by M. Pfaff to be occasioned by a new acid body
which may be separated in the following manner. A pound of the
lichen cut small is to be macerated in solution of carbonate of
potassa, until all that is soluble is separated; the above quantity
will neutralize two gros[133] of the carbonate. The filtered
liquor is to be precipitated by acetate of lead, and the brown
precipitate produced, when well washed, is to be diffused through
water, and sulphuretted hydrogen passed through it until all the
lead is separated. The filtered liquor is acid, and by spontaneous
evaporation, yields dendritic crystals. The crystals, when heated,
carbonize, but produce no odour like that of tartaric acid, and lime
is left. If they be dissolved and acted upon by alkaline carbonates,
carbonate of lime is thrown down, and alkaline salts, containing the
new acid, are produced.