of nitric acid from 1 part of the extract of aloes, and adding
water to the remaining fluid, a resinous reddish yellow substance
precipitated, which, by washing, became pulverulent—it was
discovered by M. Braconnot. Upon evaporating the liquid separated
from the precipitate, it gave large yellow rhomboidal crystals,
not transparent, and but slightly soluble. These crystals, at
first mistaken for a particular substance, were soon found to be
a combination of oxalic acid with the bitter of aloes. The bitter
substances of aloes dissolved in 800 parts of water, at 59° F., but
in a smaller quantity of boiling water. This solution has a superb
purple colour. Silk boiled in it acquired a very fine purple colour,
on which neither soap nor acids effected any change, except nitric
acid; this changed the colour to yellow, but it was restored simply
by washing in water. All shades may be given to this colour by proper
mordants. Wool is dyed black in a peculiarly beautiful manner, by
the same process, and light has no influence on the colour. Leather
acquires a purple colour; cotton, a rose colour; but the latter will
not resist soap. Dr. Liebeg thinks that this is the only substance
from which a permanent rose dye for silk may be expected.—_Ann. de
Chimie_, xxxv. 72.
25. _On the Existence of Crystals of Oxalate of Lime in Plants_.—M.
Raspail has read a memoir to the Academy of Sciences, to prove the
analogy which exists in arrangement between the crystals of silica,
which are found in sponges, and those of oxalate of lime occurring in
the tissue of phanerogamous plants.
The latter crystals were observed, for the first time, by Rafn and
Jurine, who regarded them as organs of which they knew not the
use. They were then observed by M. de Candolle, who called them
_raphides_, and gave a figure of them, which, however, is inaccurate.
These crystals are really very regular tetraedrons. In many plants,
as _orchis_, _pandanus_, _ornithogalum_, _jacinthus_, _phytolaca_
_decandria_, _mesembryanthemum deltoides_, &c. they are very small,
not being more than 1/200 of a millimetre (.0002 of an inch) in
width, and 1/10 (.004 of an inch) in length. But, in the tubercles
of the Florence iris, they are as much as 1/50 (.0008 of an inch)
in width, and 1/3 (.01312 of an inch) in length, so as to be easily
capable of examination.—_Bull. Univ._ B. xi. 376.
26. _Fallacy of Infusion of Litmus as a Test_, _by_ M. Magnus.—When
pure water is heated for a sufficient time with infusion of litmus,
reddened by an acid, it restores the blue colour. It is supposed
that the heat gradually causes the free sulphuric acid, which had
occasioned the reddening, to combine with the excess of alkali
contained in the infusion, and thus to cause the restoration of the
blue colour. Hence this preparation cannot be used to test the [p215]
presence of ammonia in a solution, as water alone produces the effect
anticipated from the alkali. The earthy salts contained in ordinary
water also produce this effect.—_Jour. de Pharmacie_.
27. _Tests for the Natural Colouring Matter of Wine_.—M. A. Chevalier
states,—i. That potash may be employed as a re-agent, to ascertain
the natural colour of wines, which it changes from red to a bottle
green, or brownish green—ii. That the change of colour produced by
this substance upon wine is different for wine of different ages—iii.
That no precipitation of the colouring matter takes place, the latter
remaining dissolved by the potash—iv. That the acetate of lead should
not be employed as a test of the colour of wines, because it is
capable of producing various colours with wines of a natural colour
only—v. That the same is the case with lime-water, with muriate of
tin mixed with ammonia, and with subacetate of lead—vi. That ammonia
may be employed for this purpose, the changes of colour which it
produces not perceptibly varying—vii. That the same is the case with
a solution of alum to which a certain quantity of potash has been
added, and which may, therefore, be used for the purpose.—_Annales de
l’Industrie_.
28. _Test of the Presence of Opium_.—Dr. Hare says he can detect
opium in solution, when the quantity is not more than that given, by
adding ten drops of laudanum to half a gallon of water. The following
is the process:—a few drops of solution of acetate of lead is to
be added to the solution containing the drug; after some time an
observable quantity of meconiate of lead will fall down: from six to
twelve hours may sometimes be required, and the precipitation is best
effected in a conical glass vessel, for then, by gentle stirring now
and then to liberate that which adheres to the side, the insoluble
salt may be collected together at the bottom. About thirty drops of
sulphuric acid are then to be poured on to the meconiate by means
of a glass tube, after which as much of a solution of red sulphate
of iron is to be added in the same manner. The sulphuric acid will
liberate the meconic acid, and thus enable it to produce with the
iron the appropriate colour, which demonstrates the presence of that
acid, and consequently of opium.—_Silliman’s Journal_, xii. 290.
29. _Denarcotized Laudanum_.—Thinking it important to ascertain
whether, by the removal of narcotine from opium, the unpleasant
effects which, according to the opinions at present entertained
upon that subject, are produced by that drug would be removed, Dr.
Hare prepared some opium with ether, guided by Robiquet’s statement
that narcotine was soluble in that fluid: the opium was shaved by
rubbing it on the face of a jack-plane, and subjected four times
successively to as much ether of the specific gravity 0.735 as would
cover it, the operation being performed in a small Papin’s digester,
at a temperature near the boiling point of ether, and each [p216]
portion of the fluid being allowed twenty-four hours for its action.
A crystalline deposition was soon observed in the ether which had
been removed from the opium, and, allowing the stopper of the vessel
to remain out, nearly the whole of the liquid evaporated in a few
days, and left much coloured crystalline matter. This, Dr. Hare has
no doubt, was narcotine in an impure state. The opium was afterwards
subjected to as much alcohol as would have been required to convert
it into laudanum, had it been in the ordinary state; and this being
administered medicinally, was found to occasion none of those uneasy
and unpleasant sensations which often follow the use of ordinary
opium.—_Silliman’s Journal_, xii. 291.
30. _Extraction of Morphia from Dry Poppy Heads_, by M. Tilloy.—Make
an aqueous extract of the heads, add alcohol to the extract,
separate the alcoholic solution, and distil it; by this means the
gummy matter is separated. An extract like syrup will be obtained
by the distillation, which, being heated to make it thinner, and of
the consistency of treacle, is to be again treated with alcohol;
a separation of more gum, with much nitrate of potash, will be
effected. The solution being withdrawn, is to be distilled, and
the extract which will remain is to be acted upon by a sufficient
quantity of water, and filtered, to separate the resinous matter
present. The morphia may then be separated from this liquid,
either by ammonia, carbonate of soda, or magnesia. Ammonia does
not precipitate all the morphia; carbonate of soda precipitates a
large quantity, but, it separates resinous matter also, which is
found mingled with the morphia. Magnesia is preferable; but as the
liquid contains much free acetic acid, it is expensive to employ
the necessary quantity of pure magnesia: the liquid may, therefore,
be partly saturated, whilst hot, by carbonate of magnesia, or even
by carbonate of lime. A judgment, when no more must be added, must
be formed from the effervescence; then pure magnesia is to be
added, which will cause the liberation of ammonia; the whole is to
be left for twenty-four hours to cool: being then filtered, the
precipitate is to be washed, and, when dry, acted upon by alcohol.
Operating in this manner, morphia may be obtained from all kinds of
poppies.—_Bull. Univ._ E. viii. 10.
31. _Preparation of Morphia_.—Some curious experiments have been
described to the Académie de Médecine, by M. Robinet, relative to
the preparation of morphia. Having operated on the residue of opium
by muriatic acid, and precipitated the morphia from the muriatic
solution by lime, he wished to ascertain whether the mother liquor
contained any morphia that had escaped precipitation. He, therefore,
passed a current of carbonic acid gas through the solution, to
precipitate the lime in excess: this precipitate being washed,
dried, and acted upon by alcohol, was found mixed with a very large
proportion of morphia, which could [p217] be thus separated. The
washings of the precipitate being examined, were found free from
morphia.
M. Henry observed, at the same time, that, from experiments made
at La Pharmacie Centrale, it appeared that much more morphia
was obtained in those processes in which lime had been used to
precipitate the morphia, than in those in which magnesia had been
used.—_Bull. Univ._ C. xi. 225.
32. _Easy Method of obtaining Meconic Acid_, by Dr. Hare.—If to
an aqueous infusion of opium we add subacetate of lead, a copious
precipitation of meconiate of lead ensues: this being collected by
a filter, and exposed to sulphuretted hydrogen, meconic acid is
liberated: the solution is of a reddish amber colour, and furnishes,
by evaporation, crystals of the same hue. A very small quantity
produces a very striking effect in reddening solution of peroxide of
iron. Instead of sulphuretted hydrogen, sulphuric acid may be used
to liberate the meconic acid: the presence of the former in excess
does not seem to interfere with the power of reddening ferruginous
solutions, but any excess of sulphuric acid may be removed by
whitening, which is not acted upon sensibly by meconic acid; Yet, the
acid procured in this way did not crystallize so handsomely, or with
so much facility, as that obtained by sulphuretted hydrogen.
33. _On a New Vegetable Acid_.—This acid is crystallizable, but the
forms have not as yet been determined: it is less soluble in cold
water than tartaric acid; its aqueous solution precipitates lime
water in white floculi, just like tartaric acid, but the precipitate,
if dissolved in muriatic acid, re-appears on adding ammonia, whilst
that produced by tartaric acid does not produce this effect. The
new acid has a greater affinity for lime than muriatic or nitric
acids, for it precipitates the muriate and nitrate of this earth in
the manner of oxalic acid, but it differs from the latter in not
precipitating a solution of sulphate of lime. With potash it forms an
acid salt, slightly soluble in cold water: it precipitates acetate
of lead, and the precipitate holds much water in combination: the
tartrate of lead, on the contrary, is anhydrous. Notwithstanding
these circumstances, the equivalent number of this acid is within
a few thousandths of that of tartaric acid: when distilled, it is
decomposed, and produces an acid yellow liquid like tartaric acid,
leaving a light charcoal burning without residuum. M. Gay Lussac is
engaged in developing the chemical history of this substance.—_Bull.
Univ._ A. vii. 327.
34. _Altheine, a new Vegetable Principle_.—M. Bacon gives the
following directions for the preparation of this substance, which
he has discovered in the _Althea officinalis_. An extract of the
roots of the plant is to be made by means of cold water, and, when
concentrated, [p218] acted upon by boiling alcohol: the latter
will dissolve the acid malate of altheine, oil, &c.: the different
alcoholic decoctions are to be put together and will throw down a
crystalline deposite as they cool; the latter is to be separated
and dissolved in water, and the solution, when filtered, is to be
evaporated by a moderate heat, until like a syrup, and then set aside
to crystallize. The crystals procured are to be washed with a small
quantity of pure water, to separate the yellow matter from them, and
then dried upon paper. These crystals appear, to the naked eye, like
grains, needles, and feathers, but under the microscope present a
hexaedral form. They are of a fine emerald green colour, transparent,
brilliant, inodorous; unaltered in the air; they redden litmus
paper, are soluble in water, and insoluble in alcohol. The aqueous
solution of these crystals, acted upon by cold magnesia and filtered,
then restores the colour of reddened litmus paper; renders syrup of
violets green; and when evaporated furnishes the altheine free from
malic acid. When thus pure, the substance crystallizes in regular
hexaedral forms or in rhomboidal octoedrons; it affects litmus and
violets as just described: it is transparent, of an emerald green
colour, brilliant, inodorous, slightly sapid, unaltered by air, very
soluble in water, not soluble in alcohol, soluble in acetic acid,
with which it forms a crystalline salt.—_Ann. de Chimie_, xxxiv. 201.
35. _Rheine, a new Substance from Rhubarb_.—By acting upon one part
of Chinese rhubarb with 8 parts of nitric acid, s. g. 1.32, at a
moderate temperature, reducing the whole to the consistence of syrup,
and then diffusing it through water, M. Vaudin obtained a precipitate
which possessed peculiar characters, and to which he gave the name
of _Rheine_. When dry, it is of an orange yellow colour, without any
particular odour, and slightly bitter. It dissolves in water as well
as in alcohol and ether: the solutions become yellow by acids, and
rose red by alkalis. It burns nearly in the manner of amadou. Rhubarb
acted upon by ether only gave a similar substance, a circumstance
which proves that Rheine exists ready formed in rhubarb, and that it
is not acted upon by nitric acid.—_Ann. de Chimie_, xxxiv. 192.
36. _On Dragon’s Blood, and a new Substance which it contains_,
_by_ M. Melandri.—Pure dragon’s blood is, according to M. Melandri,
a scarce substance; the drops in which it occurs are rarely
transparent, generally opaque, and with a rough fracture: its colour
is blood red. Besides being soluble in alcohol it is entirely soluble
in oil and also in hot water, though a large quantity of the latter
fluid is required for the purpose. The aqueous solution is bitter,
astringent, and of a fine purple colour; by cooling, it becomes milky
and red. Gelatine does not alter its appearance; a proof that the
substance contains no tannin. Sulphate of iron forms a pale reddish
precipitate, so that no evidence of gallic acid is afforded. [p219]
Supposing that this substance might contain a principle analogous to
that latterly observed by M. Pelletier in logwood, &c. a portion of
it was dissolved in strong alcohol, the solution evaporated until
very concentrated, and then poured into cold water, an agglomerated
spongy substance was precipitated, which, after being washed with
cold water and filtered, was triturated with water containing
1/100th of sulphuric acid, and exhibited traces of chemical action
at a temperature of 22° (61°.6 F.) It then deposited a substance
upon the sides of the vessel, and the liquid became yellow and very
acid. The sediment, being carefully washed with water, was of a fine
red colour, varying according to the state of aggregation; it had
no taste or smell; was flexible between the fingers, and was quite
fluid at 55° (131° F.). This substance, which the author has called
_Dracine_, has some analogy with the vegeto-alkalis, although its
affinity for acids is but slight. The sulphate may be obtained, he
says, by adding sulphuric acid diluted with alcohol to an alcoholic
solution of _dracine_, precipitating the mixture by cold water, and
then applying a little heat; the sulphate of dracine collects at the
bottom, is to be washed with cold water until the latter no longer
reddens litmus paper, and then dissolved in hot water. This solution
becomes red by the smallest quantity of alkalis, and may be used as
a very sensible test of their presence. Dracine is also a good test
for acids, assuming a yellow colour with them. The small quantity of
carbonate of lime in filtering paper may be detected by sulphate of
dracine, the yellow solution instantly becoming red from its action,
and thus showing its presence.—_Bull. Univ._ C. xi. p. 157.
37. _Purification of Madder, by the Separation of its Yellow
Colouring Matter_.—The experiments of MM. Kuhlman, Colin, and
Robiquet[36], have induced M. G. H. de Kurrer to publish the means
which he has resorted to for the purification of madder, by the
separation of the yellow colouring matter from it; and thus rendering
it more fit to supply the various red, lilac, violet, and brown
colours which are required upon wool, silk, cotton and linen. Three
tubs or vessels are placed by the side of each other: in summer they
may be in the open air under shelter, but in the winter should be
placed in an airy cellar where the temperature may be retained at 18°
or 20° R. (73° to 77° F.). The first is that in which the soaking and
fermentation is to be effected: it should be 2 feet 8 inches deep,
and 2 feet 6 inches in diameter, for from fifty to fifty-five pounds
of madder. The second, or washing vessel, should be 5-1/2 feet deep,
and 3 feet in diameter; it should have three wooden cocks fixed into
it, the first 2 feet, the second 3 feet, and the third 4 feet from
the bottom. The third tub is for deposition; its height should be
4-1/2 feet, and it should have a cock at 1-1/2 foot from the bottom.
[p220]
On commencing the operation, 50 or 55 lb. of pulverised madder are
to be put into the first vessel, water is to be added, and stirred
into the mass until it stands 1-1/2 inch above the madder. The whole
is then to be left until fermentation comes on and has formed a coat
of madder at the surface; this usually takes place in 36 hours,
and at latest in 48 hours, according to the temperature. The mass
should now be transferred into the second vessel, which is then to
be filled with water, and being left for two hours, the madder will
fall to the bottom. The upper cock is then to be opened, after that
the second, and then the third; and the water which runs from the
two latter is to be put into the third vessel, that the rest of the
madder may separate from it. The madder in the second vessel is then
to be washed a second, third, or fourth time until the washing water
is colourless. Thus purified, the madder may be used in the processes
of dyeing, according to the known methods; but it is important in
summer that it should be used immediately, that a new (the vinous)
fermentation may be avoided. The madder deposited in the third
vessel, when washed and deposited, may be used like the rest. The
liquid first separated after the fermentation may be used in the
preparation of hot indigo baths, &c. instead of madder.—_Bull. Univ._
P. vii. 352.
FOOTNOTE:
[36] See page 239 of the last volume.
38. _On Indigo and Indigogene, by M. Liebeg_.—1-1/2 part of pure
indigo, 2 parts of proto-sulphate of iron, 2-1/2 parts of hydrate
of lime, and from 50 to 60 parts of water, were digested together
for 24 hours in a close vessel, which had previously been filled
with hydrogen. The clear liquor over the sulphate of lime and
oxide of iron, had a yellowish red colour, and was separated by
a syphon filled with hydrogen, and mixed with diluted muriatic
acid, containing some sulphite of ammonia dissolved; a dense white
precipitate was formed, becoming blue in the air. This was gathered
in a filter without contact of air, and washed with boiled water
containing sulphite of ammonia in solution, and dried at 212°, in
close vessels, through which a current of hydrogen was continually
passed. The upper surface of the mass became of a blue colour, but
the lower remained of a dull white.
This white substance was called Indigogene. It did not change colour
in dry air, but under water became of a deep blue, which by drying,
assumed a coppery appearance. The blue substance volatilized by heat
without leaving any residue, forming purple vapours, which condensed,
when cold, into crystals differing in nothing from sublimed indigo.
_Indigogene_ dissolves in alkalis without neutralizing them: it is
also soluble in alcohol, but insoluble in water or acids.
A given quantity of this indigogene was acted upon by ammonia, and
the weight of the undissolved blue portion ascertained, it appeared
that the weight of the pure portion dissolved was 0.404 grammes
(6.224 grains.) The solution was put into an inverted [p221] jar,
over mercury, and oxygen gas gradually passed in until absorption
ceased, and then the liquid containing the precipitated indigo was
evaporated to dryness at 212°. The weight of the substance was
increased to 0.047, _i. e._ 11.5 per cent.
Not having obtained indigogene _perfectly_ pure, M. Liebeg did not
attempt to analyze it for the ultimate composition. He remarks,
that indigo is, perhaps, the only organic body from which one of
its constituent parts may be taken without total decomposition; and
which, by oxidation, passes to the state of an indifferent body,
having much analogy with peroxides.—_Ann. de Chimie_, xxxv. 269.
39. _On the mutual Action of Ethers, and other Substances_.—From
experiments made by M. Henry, he concludes that when metals easily
oxidizable, or oxides which unite with acetic acid, are put into
sulphuric ether, they produce larger or smaller quantities of
acetates, probably, not by decomposing the sulphuric ether, but
the acetic ether which is always mixed with it; and that it is in
consequence of the saturation of the acetic acid set free from the
ether by this decomposition, that sulphuric ether does not redden
litmus paper when evaporated, whereas it acts differently when being
slightly heated, the quantity of acetic ether contained in it is
allowed to decompose by the action of the air.
Nitric and acetic ethers are described as being easily decomposed by
the action of many bodies without the assistance of heat, if aided by
time. Amongst the products of the action are the acids of the ethers,
acetates, and alcohol which dissolves the salts formed.—_Jour. de
Chimie Méd_.
40. _Faraday’s Chemical Manipulation_.—The kindness of a friend at
Bristol has pointed out to me an error in the directions relative to
alkalimetry, which I have given in the above work: this I am desirous
of correcting, and, by permission of Mr. Brande, have the opportunity
of doing so in the _Quarterly Journal of Science_.
The mistake, which arose from using the wrong specific gravity of two
that were required in calculation, occurs in the paragraphs (599,
600,) but fortunately is prevented from occasioning any experimental
error by the directions given in (602). The acid of specific gravity,
1.141, directed to be used, is too strong for the quantities marked
upon the tube. The substitution of one of specific gravity 1.127,
will correct the error, and may be obtained very nearly by mixing 19
parts, by weight, of strong oil of vitriol, with 81 parts of water.
The alterations required may be made in the volume with a pen, as
for errors of the press, by reading “1.127” for “1.141” in lines 25
and 30 of page 276, and lines 2 and 13 of page 277; and “nineteen”
for “one” in line 27, and “eighty-one” for “four” in line 28 of page
276.—M. F. [p222]
III. NATURAL HISTORY.
1. _On the Supposed Influence of the Moon_, by M. Arago.—There
is an impression very general with gardeners, that the moon has
a particular effect on plants, especially in certain months. The
gardeners near Paris gave the name of the _lune rousse_ to the moon,
which, beginning in April, becomes full either at the end of the
month, or more generally in May. According to them the light of the
moon, in the months of April and May, injures the shoots of plants,
and that, when the sky is clear, the leaves and buds exposed to this
light become red or brown, and are killed, though the thermometer
in the atmosphere is several degrees above the freezing point: they
confirm this observation, by remarking that, when the rays of the
moon are stopped in consequence of the existence of clouds in the
air, that then the plants are not injured, although the temperature
and other circumstances are the same.