OF POISONS OF THE UMBELLIFEROUS ORDER OF PLANTS.
The Natural Order _Umbelliferæ_ contains a variety of plants, to which
narcotico-acrid properties have been at different times ascribed. But
these properties have been satisfactorily traced in the instance of four
species only, the _Conium maculatum_, _Œnanthe crocata_, _Cicuta
virosa_, and _Æthusa cynapium_. It is supposed that others may be
poisonous. But the facts on the subject are equivocal; for the several
species of the family are very apt to be confounded with one another,
and there is reason to think that other species have repeatedly been
mistaken for one of the four already mentioned.
The symptoms caused by the umbelliferous narcotics comprehend chiefly
coma, convulsions, paralysis, and delirium. But the knowledge possessed
on this head is rather vague, and the phenomena are not unfrequently
complex and difficult to observe with accuracy; so that their nature has
been sometimes misunderstood. The irritant properties of the poisons of
this tribe of narcotico-acrids are seldom well defined.
_Of Poisoning with Hemlock._
The first to be mentioned is the common hemlock, or _Conium maculatum_,
one of the most abundantly diffused of umbelliferous vegetables. It is
distinguished from all those which it resembles by its tall, smooth,
spotted stem,—its smooth leaves,—the rugged edge of the five ribs of its
fruit,—its singular mousy odour,—and the very peculiar odour of conia,
emitted when the pulp or juice of the leaves is mixed with caustic
potash. The only other umbelliferous native which has a spotted stem,
the _Myrrhis temulenta_, is easily distinguished from hemlock by the
whole plant being very hairy.
Cases of poisoning with hemlock are not infrequent on the continent, the
root having been mistaken for fennel, asparagus, parsley, but
particularly parsnep.[2217] It is generally believed to have furnished
the poison which was used in ancient times, and especially among the
Greeks, for despatching criminals; but we have not any precise
information on the subject.
A peculiar alkaloid was indicated in hemlock not long ago by Brandes,
half a grain of which killed a rabbit with symptoms like those of
tetanus.[2218] Other chemists were unable to obtain his results. But the
subject was afterwards taken up with success by Geiger, who obtained
from the plant a volatile, oleaginous alkaloid, which possesses great
energy as a poison.[2219] Mr. Morries-Stirling procured from hemlock by
destructive distillation an empyreumatic oil similar in properties to
those of hyoscyamus, stramonium and tobacco, but producing in animals a
state of pure coma.[2220]
The effects of hemlock on the animal system have been variously
described by different observers. Sometimes they have appeared to be
purely soporific like those of opium; at other times they have resembled
the effects of belladonna and thorn-apple; and in the lower animals they
are quite different, as I have witnessed them, from what they have been
described to be in man,—the phenomena being simply those of asphyxia
from paralysis of the muscles, without material convulsions and without
insensibility. Its irritant action is not well established.
Orfila observed that an ounce of the extract of the leaves killed a dog
in forty-five minutes when swallowed, ninety grains killed another
through a wound in an hour and a half, and twenty-eight grains another
through a vein in two minutes. It therefore acts by entering the
blood-vessels. The extract is a very uncertain preparation; the reason
of which is, that the alkaloid conia is very easily decomposed in its
natural state of mixture by heat or age, being converted into an inert
resinoid matter,—that the dried leaves of hemlock contain scarcely any
of it,—and that even an extract of the fresh leaves contains little,
unless prepared with a gentle heat, yet speedily.[2221] The symptoms
remarked by Orfila were convulsions and insensibility; and in the dead
body the blood of the left cavities of the heart was sometimes found
arterial.—The result of my observations is quite at variance with this
statement. In various experiments with a strong extract prepared from
the green seeds with absolute alcohol, the only effect I could remark
were palsy, first of the voluntary muscles, next of the chest, lastly of
the diaphragm,—asphyxia in short from paralysis, without insensibility,
and with slight occasional twitches only of the limbs, and the heart was
always found contracting vigorously for a long time after death. Thirty
grains of a soft extract introduced between the skin and muscles of the
back killed a rabbit in five minutes, and a five months’ puppy in twenty
minutes.[2222]
The root is much less energetic than is represented by some authors, and
probably varies in this respect at different seasons. I have found that
four ounces and a half of juice, the produce of twelve ounces of roots
collected in November, had no effect on a dog when secured in its
stomach by a ligature on the gullet; and that four ounces obtained from
ten ounces of roots in the middle of June, when the plant was coming
into flower, merely caused diarrhœa and languor. Orfila had previously
observed that three pounds of roots had no effect in the month of April;
but that two pounds in the end of May, when the plant was in full
vegetation, killed a dog in six hours.[2223] The alcoholic extract of
the juice obtained from six ounces of roots on the last day of May, I
have found to kill a rabbit in thirty-seven minutes, when introduced in
a state of emulsion between the skin and muscles of the back; and the
effects were analogous to those obtained with the extract of the leaves.
The differences depending on season will probably account for various
persons having found the juice of the root harmless. Gmelin quotes an
instance where four ounces of the juice were taken without injury. He
adds another where three ounces of the juice of the herb were swallowed
daily for eight days with as little effect. But, as he judiciously
observes, other less active plants have probably been sometimes mistaken
for hemlock.[2224]
The alkaloid, conia, seems to be the active principle of hemlock, and is
a poison of extraordinary virulence. On investigating this subject in
1835,[2225] I found that it is a local irritant, possessing an acrid
taste, and capable of exciting redness or vascularity in any membrane to
which it is applied; but that these topical effects are readily
overwhelmed by its swift and intense narcotic action. This action
consists of swiftly spreading palsy of the muscles, which affects first
those of voluntary motion, then the respiratory muscles of the chest and
abdomen, and lastly the diaphragm, so as to terminate by causing
asphyxia. The paralytic state is usually interrupted from time to time
by slight convulsive twitches of the limbs and trunk at the beginning.
The muscular contractility is impaired or annihilated by the topical
action of the poison, but not by its indirect action through absorption.
The heart is not appreciably affected; for it contracts vigorously long
after all motion, respiration, and other signs of life are extinct; and
it contains after death, not florid but dark blood in its left cavities.
The blood undergoes no alteration. The external senses are little, if at
all impaired, until the breathing is almost arrested; and volition too
is retained. But a contrary inference may be drawn by a careless
observer, in consequence of the paralytic state taking away the means,
by which in animals sensation is expressed and volition exercised. The
action of conia, in short, is confined to the spinal cord; and it acts
as a sedative, by exhausting the nervous energy.
Conia is probably a deadly poison to all orders of animals: at least I
found it to be so to the dog, cat, rabbit, mouse, frog, fly, and flea;
and Geiger killed the kite, pigeon, sparrow, slow-worm, and earth-worm
with it. It acts through every texture where absorption is carried on
readily, through the stomach, eye, lungs, cellular tissue, peritonæum,
or veins; and its activity is in proportion to the speed with which
absorption is carried on in the part. It acts therefore through
absorption. Its activity is increased by neutralization with an acid, by
which it is rendered much more soluble in water. Few poisons equal it in
subtility and swiftness. A single drop, applied to the eye of a rabbit,
will kill it in nine minutes; and three drops in the same way will kill
a strong cat in a minute and a half. Five drops, introduced into the
throat of a little dog, began to act in thirty seconds, and proved fatal
in one minute. And when two grains, neutralized with thirty drops of
weak hydrochloric acid, were injected into the femoral vein of a young
dog, it died before there was time to note the interval, so that only
two or three seconds at most had elapsed, before all internal signs of
life were extinct. This extraordinary rapidity of action seems
incompatible with its operation taking place by conveyance of the poison
with the blood to the spinal cord. Mr. Blake, as formerly mentioned (p.
15), denies that its action in this way was ever so swift in his hands,
and alleges that he could never observe the interval to be shorter than
fifteen seconds. If the reader, however, will consult the original
account of my experiment,[2226] which was made along with Dr. Sharpey,
he will see that we could scarcely be mistaken as to the interval in
that instance.
_Symptoms in Man._—M. Haaf, a French army-surgeon, has described a fatal
case of poisoning with hemlock, which closely resembled poisoning with
opium. The subject of it, a soldier, had partaken along with several
comrades of a soup containing hemlock leaves, and appeared to them to
drop asleep not long after, while they were conversing. In the course of
an hour and a half they became alarmed on being all taken ill with
giddiness and headache; and the surgeon of the regiment was sent for. He
found the soldier, who had fallen asleep, in a state of insensibility,
from which, however, he could be roused for a few moments. His
countenance was bloated, the pulse only 30, and the extremities cold.
The insensibility became rapidly deeper and deeper, till he died, three
hours after taking the soup.[2227] His companions recovered.
Dr. Watson has briefly described two cases which were fatal in the same
short space of time. The subjects were two Dutch soldiers, who, in
common with several of their comrades, took broth made with hemlock
leaves and various other herbs. Giddiness, coma, and convulsions were
the principal symptoms. The men who recovered were affected exactly as
if they had taken opium.[2228]
When the dose is not sufficient to prove fatal, there is sometimes
paralysis, attended with slight convulsions, as in a case noticed by
Orfila.[2229] More commonly there is frantic delirium. Matthiol has
related an instance of this last description, occurring in the cases of
a vine-dresser and his wife, who mistook the roots for parsneps Both of
them became in the course of the night so delirious that they ran about
the house, knocking themselves against every object which came in their
way.[2230] Kircher, as quoted by Wibmer, tells a parallel story of two
monks who became so raving mad after eating the roots, that they plunged
into water, imagining that they were turned into geese, and they were
affected for three years with incomplete palsy and neuralgic
pains.[2231] These and some other cases of the like kind, recorded by
the older medical authors, must be received with reserve. Independently
of other considerations, there is often no certainty that the poison was
really the hemlock of modern botanists, and not some other umbelliferous
vegetable.
_Morbid Appearances._—In Haaf’s case the vessels of the head were much
congested; and the blood must have been very fluid, for on the head
being opened a quantity flowed out, which twice filled an ordinary
chamber-pot. This state of the blood likewise occurred in a case which I
examined here some years ago along with Dr. C. Coindet of Geneva. A
hypochondriacal old woman took by advice of a neighbour two ounces of a
strong infusion of hemlock leaves with the same quantity of whisky,
which she swallowed in the morning fasting. She died in an hour,
comatose and slightly convulsed. The vessels within the head were not
particularly turgid; but the blood was everywhere remarkably fluid. Dr.
Coindet subsequently found that a small portion of the infusion prevents
fresh drawn blood from coagulating; but I suspect there must have been
some mistake here, for a carefully prepared alcoholic extract of very
great power, which was used in my experiments alluded to above, had no
such effect on blood fresh drawn from rabbits and dogs. On account of
this extreme fluidity of the blood, it often flows from the nose, but
the skin is much marked with lividity.[2232] The fluidity of the blood
is nothing more than the result of the proximate cause of death,—slowly
formed asphyxia.
_Of Poisoning with Water-Hemlock._
Another plant of the order Umbelliferæ, the water-hemlock or _Cicuta
virosa_, possesses also great energy as a poison; and in its effects it
appears to resemble considerably the hydrocyanic acid. The plant is
indigenous. It is easily known from other umbelliferous species
inhabiting watery places by the peculiar structure of its root-stock,
which is not fleshy, but hollow, and composed of a number of large cells
with transverse plates.
From a numerous set of experiments with the root of the cicuta performed
by Wepfer, it appears to cause true tetanic convulsions in frequent
paroxysms, and death on the third day.[2233] Simeon ascertained that the
alcoholic extract of the root is very poisonous.[2234] Schubarth found
that an ounce of the juice of the stems and leaves, collected after the
flowers had begun to blow, produced no effect on the dog.[2235] It is
probably inert, or at all events feebly poisonous in this climate,
although it grows luxuriantly in many localities. I have found that
twelve ounces of juice, expressed from sixteen ounces of roots in the
beginning of August, merely caused some efforts to vomit, when secured
in the stomach of a dog by a ligature on the gullet; that the alcoholic
extract of twelve ounces of leaves gathered at the same time had no
effect when introduced in the form of emulsion between the skin and
muscles of the back of a rabbit; and that the alcoholic extract of two
ounces of unripe seeds proved equally inert when imployed in the same
way.
_Symptoms in Man._—Wepfer has likewise related several instances which
occurred in the human subject. Among the rest he has described the cases
of eight children who ate the roots instead of parsneps. Of those who
were seriously affected, one, a girl six years old, who ultimately
recovered, had tetanic fits, followed by deep coma, from which it was
impossible to rouse her for twenty-four hours. Two of them died. The
first symptoms in these two were swelling in the pit of the stomach,
vomiting or efforts to vomit, then total insensibility, with involuntary
discharge of urine, and finally severe convulsions, during which the
jaws were locked, the eyes rolled, and the head and spine were bent
backwards, so that a child might have crept between the body and the
bed-clothes. One of them died half an hour after being taken ill, and
the other not long after.[2236] Mayer of Creutsburg mentions four cases,
which were occasioned by the roots. One of the individuals, a child
three years old, was attacked with colic, vomiting, and convulsions, and
died in a few hours. The three others, the eldest of whom was six years
of age, had coldness, paleness of the features, dilated immoveable
pupils, violent colic, general spasms, and insensibility. The action of
the heart was intermitting and the breathing oppressed. After the
remains of the roots were brought up by emetics, and infusion of gall
was administered, they gradually recovered. They had eaten between them
no more than a single root weighing about two ounces, as they had in
their possession another of that weight, which they said was not so
large. This accident happened in the middle of March.[2237]
According to Guersent, poisoning with the cicuta commences with dimness
of sight, giddiness, acute headache, anxiety, pain in the stomach,
dryness in the throat, and vomiting.[2238]
Mertzdorff has related the particulars of the inspection of three cases
which proved quickly fatal with convulsions and vomiting. Nothing
remarkable seems to have been found except great gorging of the cerebral
vessels.[2239]
_Of Poisoning with Hemlock Dropwort._
The _Œnanthe crocata_ of botanists, the hemlock dropwort,
five-finger-root, or dead-tongue of vernacular speech in England, a
species of the same family with the last two, and an abundant plant in
some localities throughout this country, has usually been held one of
the most virulent of European vegetables. It seems well entitled to this
character in general; but climate, or some other more obscure cause,
renders it inert in some situations.
It is said to be liable to be confounded with common hemlock, or _Conium
maculatum_,—a mistake which can happen only in very ignorant hands. It
has smooth, dark-green leaves, more fleshy, and much less minutely
divided, than those of hemlock; it presents a purplish appearance at the
joints only of the stem, and no diffused purple spots; its fruit is
oblong and black, not round, rough, and light brown; and its root,
instead of being single, long, tapering, and little branched, consists
of from two to ten tubers, like fingers, which are white, and terminate
in a few rootlets. These tubers are formed annually in summer from the
flowering stem of the season, and send out flowering stems the
subsequent year. During the first autumn, winter, and spring they are
firm, white, and amylaceous; but in their second summer they become more
pulpy, less amylaceous, and grayer. At all times they emit, when broken
across, an oleo-resinous juice, which quickly becomes yellow; this juice
abounds most when the plant, which is growing at their expense, is about
to flower; and it abounds much more at this period in localities in the
south of England, than in Scotland, especially in the neighbourhood of
Edinburgh.
Brotero and some others have attempted to subdivide the species into
two, the _Œnanthe crocata_ proper, and the _Œ. apiifolia_. But the best
authorities deny that these can be distinguished; and from what I have
now seen in sundry localities, it appears to me that the distinctions
pointed out by Brotero, confessedly obscure enough in themselves, are
the result of differences in climate, soil, and situation.
The only analysis of this plant with which I am acquainted is one
executed in 1830 by MM. Cormerais and Pihan-Dufeillay, who found in the
root a resinoid matter, which adheres obstinately to the solid portion
of it, and which seems to be the active ingredient.[2240] I have
subjected the roots to various processes, and among the rest to that by
which Geiger detected conia in hemlock, but without discovering any
indication of the existence of an alkaloid. My materials, however, were
not well fitted for a chemical analysis; because the œnanthe root of
this neighbourhood is inert or nearly so. The whole plant contains a
heavy-smelling volatile oil, which may be obtained by distillation in
the usual way, and most abundantly from the ripe seeds. This oil is
yellowish, viscid, and inert.
It is strange that a plant, so universally considered a potent poison,
and so frequently the cause of fatal accidents, has not yet been made
the subject of physiological investigation. A few imperfect experiments
by M. Cormerais and his companion, made with the resinoid matter of the
roots, show that this substance produces in animals dulness, convulsions
of the voluntary muscles, a semi-paralytic state of the hind legs, and
sometimes shortness of breath, vomiting, and fluid evacuations by stool.
All the animals experimented on recovered. On repeating these
experiments with larger quantities I found the resin of the root, grown
near Woolwich, and kindly sent to me by Dr. Pereira, to be a poison of
great energy and singular properties. Twenty-four grains obtained from
eight ounces of roots in the middle of December, when introduced in the
form of emulsion between the skin and muscles of the rabbit, caused in
half an hour depression, uneasiness, and hurried breathing,—then
twitches of the ears, neck, and fore-legs,—next combined spasm and
convulsive starting of the head and limbs,—then, after a quiet interval,
a more violent fit of the same kind, affecting the whole body with a
singular combination of tetanus and convulsive starting,—finally, after
several such fits, a paroxysm more violent than before, ending in
immoveable tetanic rigidity, which speedily proved fatal, 78 minutes
after the application of the poison. No morbid appearance could be
detected in the body. The heart contracted vigorously for some time
after death. These phenomena correspond in the main with what has been
recorded of the symptoms caused by the roots in man.—Dr. Pereira informs
me he had found the juice both of the root and leaves to act as a
poison, either when introduced into the peritonæum, or when injected
into the veins; and in the latter way it was so energetic as to prove
fatal in one minute.
_Symptoms in Man._—Since Lobel first took notice of the poisonous
properties of the œnanthe root in 1570, an uninterrupted series of
observations has been published, down to the present day, showing that
in France, Germany, Holland, Spain, and various parts of England as far
north as Liverpool, it is at all seasons of the year, even in October
and in the beginning of January, a poison of great activity. In several
of the cases death has been occasioned by a single handful of the roots,
in one instance by a piece no bigger than the finger, or even in
consequence of the individuals merely tasting them. A girl seems to have
had a narrow escape after eating, with an interval of three hours, two
pieces of the size of a walnut. Very seldom has death been delayed
beyond four hours, and on some occasions a single hour has been
sufficient. Sometimes the symptoms have been slow in making their
appearance, an hour and a half having occasionally elapsed before the
effects were evident; but in every instance their progress was rapid,
once the symptoms had fairly set in; and some died in convulsions almost
immediately after being taken ill.
The particular effects have been variable. Most generally the first
symptoms have been giddiness and staggering, as if from ordinary
intoxication, occasionally headache, and often extreme feebleness of the
limbs. Stupor has then generally succeeded, sometimes with the
intervention of efforts to vomit, sometimes too with an interval of
delirium. Convulsions have also commonly made their appearance in the
next place; and ere long a state of insensibility has ensued attended in
every instance with occasional violent convulsive fits like epilepsy,
and with permanent locked-jaw; which symptoms have continued till near
death. In one or two cases the individual has suddenly, without any
premonitory symptoms, fallen down convulsed, and died almost
immediately. In one or two instances again, the effects have rather been
those of irritant poisoning, namely, inflammation of the mouth and
throat, spasms of the muscles of the throat, vomiting, and excessive
weakness and faintness, without any convulsions or insensibility.—It
appears then that this plant is a true narcotico-acrid poison. The
emanations from the plant are said on some occasions to have proved
injurious; but the effect here was probably the work of the imagination.
Aware of these singular properties being generally ascribed to the
_Œnanthe crocata_, I was anxious to make a methodical examination of the
subject, physiologically as well as chemically,—especially as the plant
grows in great abundance and very luxuriantly in a locality not far from
Edinburgh. But I have found it in that situation, to all appearance,
quite inert. The juice of fourteen ounces of the root in the end of
October had no effect on a little dog when secured in the stomach by a
ligature on the gullet. The juice of sixteen ounces in the middle of
June was also without effect. An alcoholic extract of four ounces of the
full grown leaves in the end of June, introduced into the cellular
tissue in the form of emulsion, had no effect on a rabbit. An alcoholic
extract of three ounces of the ripe seeds was administered in the same
way with the same result. Finally, the resinoid extract of eight ounces
of the root, analogous to that which had proved so deadly in my hands
when obtained from Woolwich plants, had also no effect whatever, when
prepared from those growing in the neighbourhood of Edinburgh. Relying
upon these results, I ate a whole tuber weighing an ounce, without
observing any effect, except its disagreeable taste; which was the only
circumstance that prevented me from trying a larger quantity.—It may be
well to add, that, amidst the numerous cases of poisoning with œnanthe
now on record, there is not one that has occurred in Scotland. At the
same time, the common people in Scotland are not at all given to rash
experiments in cookery, or to make use of vegetables not produced by the
care of the gardener or farmer.[2241]
The only other locality from which I have been hitherto able to obtain
plants for examination is the neighbourhood of Liverpool, where a fatal
case of poisoning with it occurred near the close of last century. When
the juice of sixteen ounces of this root in the beginning of September
was secured in the stomach of a dog, efforts to vomit were produced,
followed by several fits of violent convulsions and spasm of the
voluntary muscles, a paralytic state of the fore-legs, and a constant
tendency to fall backwards; but the animal recovered.
No morbid appearances of any note have been observed after death in any
of the fatal cases which are recorded.—The most appropriate treatment
consists in the prompt employment of emetics, and diffusible stimulants.
_Of Poisoning with Fool’s Parsley._
Another umbelliferous plant of great activity is fool’s parsley, or
_Æthusa cynapium_. It has occasioned several accidents by reason of its
resemblance to parsley,—from which, however, it is at once distinguished
by the leaves being dark and glistening on their lower surface, and by
the nauseous smell they emit when rubbed. It contains an alkaloid, which
crystallizes in rhombic prisms, and is soluble in water and alcohol, but
not in ether. It was discovered by Professor Ficinus of Dresden.[2242]
Orfila found that six ounces of the juice, when retained in the stomach
of a dog, by a ligature, caused convulsions and stupor, and death in an
hour.[2243]
_Symptoms in Man._—Some interesting information on the characters and
properties of this plant is contained in the Medical and Physical
Journal. Among other cases the writer relates those of two ladies who
ate a little of it in a sallad instead of parsley, and who were soon
seized with nausea, vomiting, headache, giddiness, somnolency, pungent
heat in the mouth, throat, and stomach, difficulty in swallowing and
numbness of the limbs.[2244] Gmelin has related the case of a child, who
died in eight hours in consequence of having eaten the æthusa. The
symptoms were spasmodic pain in the stomach, swelling of the belly,
lividity of the skin, and difficult breathing.[2245] In two children who
recovered, the chief symptoms at the height of the poisoning were
complete insensibility, dilated, insensible pupil, and staring of the
eyes. In one of them there was also frequent vomiting, in the other
convulsions. The treatment consisted in the administration of milk,
sinapisms to the legs, and cold spunging with vinegar.[2246]