was the _gadus Polachius_, or whiting Pollack. It was about two
feet long, and it is probable its active enemy had fastened [p074]
on it after it had been hooked; if _before_, it would indicate an
extraordinary insensibility to pain in an animal that could attend to
the calls of appetite, whilst another was preying on its vitals. The
fish which had fastened on the pollack, was the _petromyzon marinus_,
or sea lamprey. It was nearly three feet long, and resembled a large
eel in shape. Its general colour was a dull brownish olive variegated
with bluish blotches; the back darker, and the belly paler, inclining
to yellow. The eyes were small, and the mouth large and oval; but
when distended, circular. The inside of the jaws was deeply concave,
and studded with circular rows of sharp triangular teeth, that issued
from corresponding orange-coloured papular protuberances, which
formed the gums; the tongue was short and crescent-shaped, furnished
with a row of very small teeth round the edge. On the top of the
head was a small orifice, or spout-hole, from whence it discharged
the superfluous water taken at the mouth. But the circumstance that
more particularly distinguished it, was that which gave rise to the
vulgar error that it had sixteen eyes. On either side of the neck,
commencing just below the real eyes, was a row of seven equidistant
spiracles exactly resembling eyes; they are, however, holes lined
with a red membrane, and all opening into the mouth, an apparatus to
supply the place of gills, whose functions are to extract oxygen from
the water, and so perform the office of lungs in aquatic animals. It
had two dorsal fins, one on the lower part of the back, narrow, with
a roundish outline; the other commencing where the first terminated.
The spine was cartilaginous, without processes. The pericardium,
containing a small heart, was a remarkably strong membrane, and the
liver was as green as grass.
This fish is not uncommon in the North Seas, though it most abounds
in the Mediterranean, where, from earliest times, it was esteemed a
luxurious dish. Fish-ponds were purposely constructed to preserve
it. On our coast, Pennant observes, that it is found most frequently
at the mouth of the Severn, which river it sometimes ascends, where
it is occasionally taken, firmly attached to a stone by its mouth,
while its tail and body are waving freely to the current. Its
adhesion at such times is so strong, that it may be lifted with a
stone of twelve pounds weight appended to its mouth. This faculty
is owing to its [p075] power of suction; while the circumstance of
its circular jaws coming in close contact with the surface of the
body excludes the external air within the cavity of the mouth, and
so adheres like the hand placed on the cup of an air-pump. It is
from this remarkable property, that its scientific name has been
imposed[25]. Its vulgar name, lamprey, from lampetra, has a similar
derivation. By the Romans it was named muræna. As this fish was well
known and highly prized by the ancients, there is none that has been
so frequently described and alluded to. Aristotle, Pliny, Tacitus,
Columella, Ælian, Seneca, and Oppian, have mentioned its properties
and habits, which correspond exactly with those I have described
above. Pliny says, in the northern parts of France, and consequently
contiguous to the British Isles, the lampreys have seven spots in
the jaws, resembling the constellation of the plough, evidently the
same as the eyes, which vulgar opinion assigns to the fish[26]. Their
extreme voracity was such, that criminals were thrown among them to
be devoured. Seneca relates, that Vedius Pollio, a Roman knight,
ordered his servant, who had broken a crystal vase, to be thrown into
a large pond of lampreys[27]; and Columella writes, that they were
sometimes seized with a rabid fury, that resembled canine madness;
in the access of which, they seized upon other fish, so that it was
impossible to keep them in the same pond[28]; and to account for this
extraordinary ferocity, Oppian and others assert, that the lamprey
is impregnated by a serpent; the one issuing from the sea, and the
other rushing down to the rocks, inflamed with madness, to consummate
the impregnation; and adds, that the extraordinary intercourse was
effected by the lamprey seizing the serpent’s head in its [p076]
mouth[29]. This singular copulation was the reason why the Romans,
who were immoderately fond of lampreys, did not wish to eat them,
when impregnated by the supposed serpent. Horace, therefore, makes
Nasidienus, among the blunders of his supper, serve it in that
state[30].
Lampreys were a favourite dish with our own early monarchs. Henry
II. died by eating them to excess. The celebrated Pope also owed his
death to a surfeit of them. Doctor Johnson remarks in his life of the
poet, that he was in the habit of cooking them himself in a silver
saucepan. The Corporation of Oxford still make up a periodical pye
of this fish for the king, in compliance with ancient usage. But
lampreys have lost their rank at corporation feasts, in consequence
of the more delicious and wholesome turtle being introduced into
modern cookery.
I have never noticed lampreys in the Dublin fish-market; and though
they are frequently used in the South of Ireland, I do not know if
they have ever been made an article of food in Dublin, or the north,
where they are rarely met with.
C.
FOOTNOTES:
[25] Petromyzon, _a_ πετρον, saxum, and μυζαω, sugere.
[26] In Gallia septentrionale murænis omnibus dextra in maxilla
septenæ maculæ ad formam septentrionis aureo colore fulgent. PLIN.
_Hist. Nat._ lib. ix. cap. 39.
[27] Fregerat unus ex servis crystallinum ejus; rapi eum Vedius
jussit, nec vulgari quadam morte periturum, murænis objici jubebatur
quas ingens piscina continebat.—SENECA _de Irâ_, lib. ii. cap. 40.
[28] Commisceri eas cum alterius notæ piscibus non placet, quasi
rabie vexantur quod huic generi velut canino solet accidere. Sævitia
persequuntur squamosos plurimosque mandendo consumunt. COLUMELLA _de
Re Rusticâ_, lib. ix. cap. 17.
[29] Αμφι δε μυραινης φατις ερχεται ουκ αιδηλον
Ὥς μεν γαμει τε και εξ ἅλος ερχεται αυτη
Προφρων ἱμειουσα παρ’ ιμειροντι γαμοιο
Ητοι ὁ μέν φλογεῃ τεθοωμενος ενδοθι λυσσῃ
Μαινεται ἔις φιλοτητα και ἔγγυθι συρεται ἅκτης
Πικρος ὄφις. κ.τ.λ.—OPPIAN, _Halieut._ lib. i. V. 554.
[30] Adfertur squillas inter muræna natantes, In patinâ porrecta:
“hæc gravida,” inquit, “Capta est.”—HOR. lib. ii. Sat. 8. lin. 46.
_Observations upon the Motion of the Leaves of the Mimosa Pudica_.
[To the Editor of the Quarterly Journal of Science.]
Dear Sir,
Towards the latter part of this summer, Mr. Gilbert Burnett and
myself made several experiments with a view to ascertain the nature
of the movements exhibited by the sensitive plant. We afterwards
found that the greater part of the facts which we had observed, had
been previously described by Mr. Lindsay [p077] and Dr. Dutrochet.
Mr. Lindsay’s observations are to be met with in a MS. preserved in
the library of the Royal Society, which is dated July 1790: this
essay is alluded to by Dr. Smith in his “Introduction to Botany.”
Dr. Dutrochet’s experiments were published in his “Recherches
anatomiques et physiologiques sur la Structure intime des Animaux
et des Végétaux,” which appeared in 1824. With the latter author
the reputation of originality is likely to rest: not undeservedly,
indeed, as there is no reason to suppose that _his_ experiments
were suggested by a knowledge of those performed by Lindsay. It
is, however, an act of literary justice to secure to Mr. Lindsay
the credit of undoubted priority in describing the phenomena which
he noticed in common with Dutrochet. I have drawn up the following
remarks partly for this purpose—partly to have an opportunity of
mentioning some circumstances which escaped the observation of both
experimentalists.
The leaves of the Mimosa Pudica consist either of one or two or
three pairs of leaflets, and occasionally terminate by an odd
one. Each leaflet bears from twenty to sixty subleaflets, which
are disposed in pairs. The petiole or stalk of each leaf, at the
extremity which is attached to the branch or stem of the peant,
swells into an intumescence varying from three to five in length. A
similar intumescence, of proportionate dimensions, is seen upon each
subpetiole, where it is articulated with the petiole, and upon the
base of the stalk of each subleaflet: the intumescence is the part in
which motion takes place.
During the day-time the petioles are observed to have a direction
upwards, or rather to form an acute angle with the upper part of
the stem or branch, to which they are attached: the subpetioles are
divergent: the subleaflets are spread out, so as to lie nearly in one
plane. (_Fig._ 1.)
During the night the petioles are found to be depressed; the
subpetioles to be drawn together, the subleaflets folded, the upper
or solar surfaces of each pair being brought into contact. (_Fig._ 2.)
The leaves rise, the leaflets diverge, and open by throwing down
their subleaflets, at daybreak: the opposite changes occur about
sunset. The experiments that are to be described, are supposed to be
performed in the day-time. [p078]
[Illustration: _Fig._ 1.]
If a terminal subleaflet be pinched with forceps, or cut with
scissors, it rises, together with its fellow; then the next pair
rise; then the next; and so on in succession, till all the pairs of
subleaflets upon the same subpetiole are folded. In a little time
afterwards, the petiole is bent downwards at its intumescence; and in
a few seconds more the remaining leaflets upon the same petiole fold
their subleaflets in pairs, from the base towards the point of the
leaflet.
[Illustration: _Fig._ 2.]
If a subleaflet be burnt, instead of being cut or pinched, the
phenomena above described occur more rapidly: and after they have
taken place, the adjoining leaves upon the same branch are bent down
in succession, their leaflets brought together, and their subleaflets
folded. If the plant be very vigorous and lively, an impression
[p079] made upon one leaf affects the rest in succession. It is well
known that the stem, branches, flowers, and roots of the sensitive
plant have no motion. But M. Desfontaines observed that, on touching
the roots with sulphuric acid, the leaves become folded; and M.
Dutrochet obtained a similar result on burning either the flower or
the stem.
[Illustration: _Fig._ 3.]
[Illustration: _Fig._ 4.]
[Illustration: _Fig._ 5.]
If the plant be shaken, all the leaves are simultaneously thrown
down, and their leaflets folded. Mr. Lindsay attempted to elucidate
the action of the intumescence in raising and depressing the petiole,
in the following manner. He cut out a portion from the upper or solar
surface of the intumescence; after which he found that the petiole,
upon recovering, rose higher than before, (_Fig._ 3.) From another
leaf he removed the inferior portion of the intumescence: he found,
upon _this_ injury, that the leaf declined more than before, and
did not again rise, (_Fig._ 4.) He noticed that a thin slice, pared
from either surface of the intumescence, has a like effect, but in
a less degree than a deep excision: and he found that when similar
experiments are made upon the intumescence of the subpetiole, there
is no essential difference in the result.
Thus Mr. Lindsay discovered, that the force which raises the petiole
exists in the lower part of the intumescence, and that which
depresses it, in the upper. He seems to have considered that the
temporary excess of force in either part is produced by an impulsion
of the sap from the vessels of the yielding portion into those of the
opposite portion. [p080]
Dr. Dutrochet viewed these phenomena in some respects more justly. He
remarked, in addition to what Lindsay had observed, that if, instead
of the upper and under surface, the lateral part of the intumescence
be removed, the petiole becomes not raised or deflected, but inclined
towards the side on which it is injured (_Fig._ 5); and that if
longitudinal slices of the upper, or under, or lateral portions
of the intumescence are immersed in water, these separate slices
immediately become incurvated, that edge being concave which looks
towards the axis of the intumescence. From these facts Dutrochet
inferred that the texture of the intumescence possesses some
modification of irritability; that, when excited, each length of the
intumescence (to use a very imperfect expression) forcibly assumes
an incurvated figure, like a curved spring returning from a state of
temporary extension; that the petiole is raised, when the action of
the lower part of the intumescence predominates; is depressed, when
the upper portion acts with increased energy.
Mr. Burnett and myself had arrived at very similar conclusions
respecting the agency of the intumescence, before we became
acquainted with the inquiries of Lindsay and Dutrochet.
In Dutrochet’s able researches, a more exact analysis, however,
was obtained of the functions of this part. He discovered that the
cortex of the intumescence is the seat of its irritability: for upon
wholly removing the bark, so as to expose the ligneous substance, the
petiole was found to have been rendered motionless. Nevertheless,
the intumescence, thus mutilated, remains capable of transmitting an
impression made upon its leaflets to the leaves adjoining, Dutrochet
further ascertained, that the ligneous substance alone is fitted to
convey the peculiar stimulus, which spreads, from a point of the
plant that has been irritated, to the adjoining leaves.
The experiments already mentioned appear to explain the mode in which
the elevation and depression of the petiole, and the divergence
and approximation of the subpetioles are produced. It is probable
that the contrivance for folding and expanding the subleaflets is
of a similar nature. Mr. Burnett and myself conjectured that each
subleaflet is raised by the under part of the intumescence that
exists at its base, and [p081] depressed by some action of the upper
portion of the same intumescence. In trying the soundness of this
hypothesis, we met with the following evidence in its favour:—
Mr. Lindsay had observed, that at the moment when the petiole is
depressed, the under part of its intumescence assumes a deeper
colour. But the under part of the intumescence of the petiole is
the portion which is shortened during its depression, and which is
overcome on this occasion by the superior force of the upper portion.
Now it is to be remarked that in the subleaflets the upper part
of the little intumescence belonging to each corresponds, in one
respect alluded to, with the lower portion of the intumescence of
the petiole; _it is the portion shortened when the leaf is folded_.
And we found, upon examination, that it likewise distinctly changes
colour at the moment when the subleaflet rises, while the under
surface of the intumescence of the subleaflet does not change its hue.
In pursuing this inquiry, another point of correspondence between
the mechanism which depresses the petiole, and that which raises the
subleaflets, was stated, which has yet additional interest.
[Illustration: _Fig._ 6.]
[Illustration: _Fig._ 7.]
[Illustration: _Fig._ 8.]
When the plant is not in its most lively state, the under surface of
the intumescence of the subleaflet (_b_, _Fig._ 2,) and the upper
surface of the intumescence of the petiole (_a_, _Fig._ 6,) may be
pricked with a needle, without producing action. But if the opposite
surfaces, those namely, which change colour and are shortened when
the petiole is depressed and the subleaflets folded, are touched
with the point of the needle these actions are instantaneously
produced. Here the [p082] subleaflet is most delicately sensible;
_a slight touch_ with the point of a needle upon the upper surface
of the intumescence of the subleaflet (_c_, _Fig._ 1,) causes the
single subleaflet so stimulated to rise; and in this manner all the
subleaflets upon one side of a leaflet may be raised, their fellows
remaining expanded: if the touch be something sharper, the fellow
subleaflet rises at the same time; if ruder still, the next pair of
leaflets fold directly afterwards, and the irritation then proceeds
entirely through the leaflet. But the most satisfactory and curious
results are obtained on stimulating the extension surface of the
intumescence of the petiole. The needle may be applied to every point
upon the upper or solar half of the intumescence of the petiole
(_a_, _Fig._ 6,) without producing any visible effect; but if the
irritation be applied upon the under half, (_d_, _Fig._ 6,) either
quite below or laterally, the petiole is immediately depressed. The
transition is abrupt from the surface against which the needle may be
made to prick, without exciting action, to one which, when the needle
reaches it, causes the petiole to be instantaneously thrown down.
It appears, therefore, that each intumescence has a surface
especially adapted to receive mechanical impressions; which surface
is placed on the side of the intumescence opposite to that, by which
the consequent motion is produced. A curious but vague analogy may be
traced between these surfaces of the sensitive plant and the organs
of sense in animals.
We painted with a thick layer of lamp-black in oil the intumescence
of different petioles in different ways; the upper surface of one,
the under surface of another, the side of a third. The experiment was
followed by no sensible effect. After a few minutes the petioles,
which had been thrown down by the operation, rose again in each case,
and fell again as readily as before upon being stimulated afresh.
We tried what result would ensue upon slitting the intumescence of
the petiole horizontally. The petiole, after this injury, did not
recover its usual direction; the intumescence appeared to have wholly
lost its properties; the leaf seemed to depress the petiole by its
weight alone, yet the leaflets expanded, and exhibited their usual
irritability, upon the depending stalk. The same effect, however, was
observed, when the [p083] intumescence was divided by a longitudinal
incision, made vertically instead of horizontally.
I have already mentioned that Dutrochet discovered that the ligneous
fibre is the channel, along which an impression is conveyed from
one part to another. Mr. Burnett and myself had made one or two
experiments upon the course which the irritation follows when
spreading from leaflet to leaflet, where several are placed upon the
same petiole.
If the upper third of a petiole bearing four leaflets be divided
longitudinally, the irritability of the leaflets remains for many
days unimpaired; upon cutting with scissors one subleaflet after the
plant has recovered itself, the irritation is observed to descend
the wounded leaflet, and then to pass to that adjoining upon the
same side of the petiole: afterwards the petiole falls, but there
the effect stops; it does not extend to the two other leaflets;
the direct route is cut through, and the irritation seems to find
no circuitous way, as might have been expected, perhaps through
the intumescence of the petiole back again to the leaflets, on its
summit. If on a petiole, bearing four leaflets, a lateral incision be
made, cutting the petiole half through it at a point between the two
leaflets which are situated on one side, upon irritating either of
the leaflets, between which the incision has been made, it folds its
subleaflets; then the two opposite leaflets fold _their_ subleaflets;
and _last of all_, the leaflet next adjoining that first irritated,
but isolated from it by the incision, becomes folded.
In the few remarks which I have thus put together, I have quoted
Lindsay and Dutrochet only as far as their researches anticipated
my own: I leave unnoticed many experiments, in several of which
these authors are again found to have accidentally coincided. The
experiments to which I allude do not, however, serve to illustrate
the nature of the motion exhibited by the sensitive plant, to the
examination of which subject alone my attention was, in the present
instance, directed, in the expectation that it might throw light upon
the obscure and interesting subject of muscular action.
I remain, my dear Sir, Your’s truly,
HERBERT MAYO.
19, _George Street, Hanover Square_,
_August 29, 1827_.
[p084]
_Experiments on the Nature of Labarraque’s disinfecting Soda
Liquid_. By M. Faraday, F.R.S., Corr. Mem. R. Acad. Sciences, Paris,
&c. &c.
1. The following experimental investigations relate to the nature of
that medicinal preparation which M. Labarraque has lately introduced
to the world, and named _Chloride of oxide of Sodium_. They were
occasioned by the accounts which were given of this and other
substances of similar power, to the members of the Royal Institution,
at two of their Friday evening meetings[31]; the value of the
preparation, the uncertainty of its nature, and the inaccuracy of its
name, all urging the inquiry.
2. In the first instance the inquiry was directed to the nature of
the action exerted by chlorine gas upon a solution of carbonate
of soda, questions having arisen in the minds of many, whether it
was or was not identical with the action exerted by the same gas
on a solution of the caustic alkali, and whether carbonic acid was
evolved during the operation or not. Chlorine gas was therefore
carefully prepared, and after being washed was sent into a solution
of carbonate of soda, in the proportions directed by M. Labarraque;
_i. e._ 2800 grains of crystallized carbonate of soda were dissolved
in 1.28 pints of water; and being put into a Woulfe’s apparatus,
two-thirds of the chlorine evolved from a mixture of 967 grains
of salt with 750 grains of oxide of manganese, when acted upon by
967 grains of oil of vitriol, previously diluted with 750 grains
of water, were passed into it; the remaining third being partly
dissolved in the washing water, and partly retained in the open space
of the retort and washing vessel. The operation was conducted slowly,
that as little muriatic acid as possible might be carried over into
the alkali. The common air ejected from the bottle containing the
solution was collected and examined; but from the beginning to the
end of the operation not a particle of carbonic acid was disengaged
from the solution, although the chlorine was readily absorbed.
Ultimately a liquid of a very pale [p085] yellow colour was obtained,
being the same as M. Labarraque’s soda liquor, and with which the
investigations were made that will hereafter be described.
3. An experiment was then instituted, in which the effect of excess
of chlorine, upon a solution of carbonate of soda of the same
strength as the former, was rendered evident. The solution was put
into two Woulfe’s bottles, the chlorine well washed and passed
through, until ultimately it bubbled through both portions without
absorption of any appreciable quantity. As soon as the common air
was expelled, the absorption of the chlorine was so complete in the
first bottle, that no air or gas of any kind passed into the second,
a proof that carbonic acid was not liberated in that stage of the
experiment. Continuing the introduction of the chlorine, the solution
in the first bottle gradually became yellow, the gas not being yet
visible by its colour in the atmosphere above the solution, although
chlorine could be detected there by litmus paper. Up to this time no
carbonic acid gas had been evolved; but the first alkaline solution
soon acquired a brighter colour, and now carbonic acid gas began
to separate from all parts of it, and passing over into the second
bottle, carried a little chlorine with it. The soda solution in the
first bottle still continued to absorb chlorine, whilst the evolution
of carbonic acid increased, and the colour became heightened.
After some time the evolution of carbonic acid diminished, smaller
quantities of the chlorine were absorbed by the solution, and the
rest passing into the atmosphere in the bottle, went from thence
into the second vessel, and there caused the same series of changes
and actions that had occurred in the first. The solution in the
first bottle was now of a bright chlorine yellow colour, and the gas
bubbled up through it as it would through saturated water.
4. When the chlorine had saturated the soda solution in the second
bottle, and an excess of gas sufficient to fill several large
jars had been passed through the whole apparatus, the latter was
dismounted, the solutions put into bottles and distinguished as
the saturated solutions of carbonated soda; they were of a bright
greenish-yellow colour, and had an insupportable odour of chlorine.
5. The saturated solution (4) was then examined as to the [p086]
change which had been occasioned by the action of the chlorine. It
bleached powerfully, and apparently contained no carbonated alkali:
but when a glass rod was dipped into it and dried in a warm current
of air, the saline matter left, when applied to moistened turmeric
paper, reddened it considerably at first, and then bleached it; and
this piece of paper being dried and afterwards moistened upon the
bleached part, gave indications of alkali to fresh turmeric paper.