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A nice listing of poisons and their symptoms and signs. This is by no means
exhaustive. Note that, in real life, most poisoning cases are accident or
suicide rather than murder. It's not very good as a murder weapon as labs can
always detect it in the body. However, sometimes poisoning deaths look like
natural deaths, unless a toxicological analysis in done.
Please note that this is intended for fiction use only, not for
A useful website is the "Bad Bug Book by the Center
for Food Safetly and Nutrition, which describes various food-poisoning agents,
from bacteria, to toxins (bacterial, fungal, plant, combination), and others,
often with links for more info.
Important note: This whole section has been compiled from books and
websites, with occasional help from people working in this field. Like the rest
of Deep Background (of which this is only a small part), this information is
designed for writers of X-Files fiction, and covers only those things that they
might be expected to need. It is not a comprehensive guide to the subject.
- Carbon monoxide Odorless and colorless. Non-irritating. Found in
car exhausts. It is cumulative - repeated small doses can build up over time. It
kills by preventing the blood from carrying oxygen. Symptoms:
Initially, dizziness and headaches when exerting yourself, then when at rest
too. A higher dose affects coordination and makes the heart throb. Then comes
collapse and death. Often the victim is unaware and just drifts slowly to sleep.
Post-mortem appearance: Pinky skin. Cherry-red blood. Blood is fluid and
doesn't want to clot. Lungs congested and the upper air passages contain a
frothy fliud. Carbon monoxide remains in the blood for up to six months after
- Hydrochloric As with most acids, not usually used to kill someone,
but can be used to dispose of the corpse afterwards. Corrosive and colorless.
- Nitric Usually colorless, though goes brown when oxidized.
- SulphuricColorless. A dehydrating agent that extracts water from
the body. Is strong enough to eat through bones as well as flesh. This process
takes about 4 hours.
- Potassium hydroxide (Caustic potash) Very corrosive. If consumed,
it burns then mouth and stomach, then makes the lips and tongue swell. Vomiting
is of a brown substance, with bits of dead skin and flesh in it. Skin is cold
and clammy and the heart beat feeble and rapid. Death comes from damage to the
stomach, asphyxia to the corrosion of the larynx, or congestion of the lungs due
to breathing dead material. Also sometimes used to dispose of bodies.
- Sodium hydroxide Similar to above. Often found in household
- Ammonia Colorless and smelly. Not usually used as a murder weapon.
If it is consumed in its liquid form, death is usually from corrosion of the
larynx. Lungs are congested and frothy, and the blood is dark and resistent to
clotting. Exposure to ammonia gas gives a sensation of suffocation, a burning
sensation in the mouth and stomach, and vomiting which contains blood and smells
Synthetic Organic Substances
- Acetylsalicylic Acid (Aspirin) Symptoms: Nausea, though not
neccesarily vomiting. Mental confusion and hearing difficulty. Sleepiness
leading to coma. Pulse is high, breating is deep and slow. Post-mortem
appearance: Dehydration. Fluid on the lungs. Liver and kidneys degernated.
Acid and granular urine.
- Barbituric AcidUsed as sedatives, but addictive and very easy to
overdose on. Often used in suicide. Symtoms (of a fatal dose): Headache,
vertigo, incontinence. Sleepiness, sometimes with hallucinations, leading to
coma. Small pupils won't react to light. Pulse quick and weak. Skin cold and
clammy. Breathing loud and heavy, and towards the end may stop periodically and
start again. Post-mortem appearance: Congested lungs. Signs of
broncho-pneumonia. Frothy fliud in air passages. Brain congested and softened.
Full bladder. Urine tests reveals present of barbituate.
- Chloroform Heavy colorless liquid. Nice smell. Used as
anaesthetic, and to render a victim unconsious. However, it's not easy to
cholorform a sleeping victim without waking them, and it can take up to 15
minutes to knock the victim out. Victim often convulses as the drug takes
effect. Skin blisters on face, where choloroform is in contact with the skin.
Prolonged inhalation leads to death by heart failure, and ingestion by heart and
Chloral Hydrate is related. It is usually ingested and, in small doses, can
knock someone out very quickly if, for example, placed in their drink. Larger
doses cause death by heart and lung failure
- Cyanide (or Prussic Acid)Quickly fatal in small doses, killing by
interfering with the blood's capabilities to absorb oxygen. Faint smell of
bitter almonds, though less than the mystery writers tell us.
- Metaldehyde Found in camping stove fuel and slug pellets. Doesn't
taste too nasty, but soon leads to vomiting. Then restlessless, tremors of the
arms, mild delirium. Then cramps and convulsions, unconsiousness, coma. Death
is from respiratory failure and comes within 3 or 4 days.
- Nitrobenzine(Oil of Mirbane) Yellow oil in some perfumes and dyes.
It reacts with the blood and corrupts it, and also paralyzes the central nervous
system. Initial symptoms: burning sensation then numbness in mouth.
Pallor. Unconsiousness. Death within about 2 hours by respiratory failure. Post-mortem
appearance: Cyanosis - greyness at extremities. Blood dark and thick.
Stomach has a red congestion and bleeding under the surface. Organs smell of
bitter almonds, like with cyanide.
- Oxalic Acid Found naturally in rhubarb leaves and also used in some
bleaches. Kills by removing calcium from the blood. Symptoms are stomach
pains, muscle tremors, rapid breathing, convulsions, coma and death. Can kill
with a very small dose. Post-Mortem Appearance Solid calcium oxalate in
- Paraldehyde Colorless liquid similar in effect to Chloral Hydrate.
Tastes horrid and burns, but in small doses produces euphoria and can be
addictive. Damages the digestive system, leading to emaciation. Continued use
affects the mind and memory. Needs quite a large dose to cause death.
- Lysol and Phenol Lysol is a disinfectant. Small doses can kill,
causing failure of just about everything in the body. Phenol is carbolic acid.
Both contain cresol.
- Aconite Derived from monks hood (a plant). Incredible poisonous,
killing with only a tiny dose. Symptoms: Numbness and tingling in mouth
and throat starting within minutes or an hour. This soon extends across whole
body. Extremities feel cold and clammy. Limbs lose power and sight and hearing
dimmed. Mental facilities okay. Pulse weak and variable. Eye dilated Death by
respiratory failure between around 10 minutes and three hours, depending on
- Atropine Found in the belladonna plant. Very poisonous, though not
as much so as aconite. Can be absorbed through the skin as well as ingested.
Symptoms: Dry mouth and tongue. Difficultly swallowing. Flushed skin
leading to rash on upper body. Headache leading to giddiness, hallucination,
delirium. Breathing and pulse fast. Dilation of pupils is most distinctive
feature - eyes look almost black. Later, signs of paralysis, then coma and
- Cocaine Not often used in murder. An overdose overstimulates the
- Colchicine Pale yellow crystals from meadow saffron. Kills in small
doses. Fatal within 7 to 36 hours. Death is by paralysis of repiratory system.
- Coniine Oily liquid from hemlock. Not painful to die from it, but
progressively paralyses the body until in the end heart or lungs fail. No
post-mortem signs except of asphyxia.
- Gelsemium Seldom used. Symptoms are muscular weakness with slow
pulse, dilated pupils. Death from respiratory failure.
- Nicotine Liquid at room temperature (the only alkaloid, along with
coniine, which has this property). Yellowish oil, discolouring to dark brown in
light. Poisoning usually done with insecticide, as this is where nicotine is
used (only a tiny amount in cigarettes) Absorbed in skin or drunk.Symptoms:
Burning sensation in mouth. Vomiting and diarrhoea. Mental confusion and
dizziness. Convulsions then death vy paralysis of respiratory system. Death is
within minutes - only cyanide is quicker.
- Opium and Morphine Raw opium very seldom used as a poison as acts
slowly and has a strong smell. Morphine is a white crystalline substance
extracted from opium. Used as analgesic, but overdose can be fatal. Fatal dose
varies but usually about 5 grams. Symptoms start within minutes.
Drowsiness. Nausea. Face swollen and colored. Patient feels cold. Cyanosis
(greyness of extremities) Eyes dilate to pinpoints that don't react to light and
dark (this is the most distinctive symptom). Breathing slow and noisy. Pulse
slow and weak. Death is by respiratory failure.
- Physostigmine Used by some tribes as an "ordeal" poison.
Causes excitement and hallucination. Overdose causes vomiting. Severe overdose
interferes with heart and causes death.
- Scopolamine (Hyposcine) Naturally occurring in several plants
including belladonna and henbane. Can be administered internally as well as
externally. Tiny amounts can be used to treat anxiety or motion sickness. Larger
doses break down ability to make reasoned judgments, so has been used as a "Truth
Drug" Even larger doses cause hallucinations and floating sensation. Death
is when the heart is affected.
This was found in "Red Museum," in the kidnapped teenagers. Scully
described it as an anaesthetic which, in large quantities, is a hallucinogenic
and has been used by kidnappers to subdue their victims. She also said it is a
controlled substance, only obtainable by doctors.
- Strychnine Derived from a berry. Colorless solution with a very
bitter taste, noticeable even in very weak solutions. Very powerful. 100
miligrams is always fatal, though much smaller doses have killed within 20
minutes. Symptoms: Symptoms come on within 2 or 3 hours - sometimes much
faster - but them proceed rapidly. Restlessless. Feeling of suffocation. Face
muscles contract and victim looks as if they're grinning. This is followed by
very violent and distorting contractions, followed by a period of rest, then an
attack of even more violent contractions. Patient is conscious but in agony,
unable to speak because of lockjaw. Pulse is incredibly high. Death is during a
convulsion, from paralysis of respiratory system. Sometimes confused with
tetanus or epilepsy (though different from epilepsy as person is conscious
Spanish fly. When crushed and rubbed on skin, causes blisters. Taken orally,
a small dose results in kidney damage. Larger doses inflame mouth, throat and
stomach. Vomit and urine contain blood. Headache, delirium, convulsions, leading
Inorganic and Metallic Poisons
- Antimony Usually used in form of a tartar emetic -antimony tartrate
- a white metallic powder. Sometimes doesn't work and victim is sick and gets
rid of it before it can work. For this reason, and because a large dose is very
obviously, is normally used by poisoners in small cumulative doses. Symptoms
of large doses Burning in throat. Difficulty swallowing. Stomach pain and
vomiting. Faintness. Extreme depression. Pulse is fast at first, then slows down
until very slow and irregular. Skin cold and clammy, sweating heavily. Cyanosis
(blueness) of extremities. Cramps in legs then elsewhere. Death is by heart
failure. Symptoms of cumulative doses Sickness, stomach ache, loss of
appetite, diarrhea - just like lots of illnesses.
- Arsenic Found in lots of places, including occurring naturally in
the human body. Used either as yellow oxide, white oxide or vapour, which smells
of garlic. White oxide is virtually tasteless and easily masked by food. Can be
given cumulatively - fatal dose can build up slowly over time. In this case,
symptoms can look like food poisoning. Symptoms vary according to type
and method. White oxide poisoning starts with irritation of throat, nausea,
faintness, depression. Then vomiting, tinged with blood.and mucus. Severe
abdominal pains, exacerbated by touch. Tongue is white and furry and throat
constricted. Diarrhea after 12 - 18 hours. Cramps in legs at same time. Pulse
weak, rapid and regular. Cyanosis - blueness of extremities caused by lack of
oxygen in blood. Death comes when still conscious. Post-Mortem Appearance
Found in every part of affected body, even bones and hair, and even years after
death. Stomach is very inflamed - even ulcerated. This is even if the poison was
administered by being inhaled as a vapor or passing through skin.
- Barium Used in various soluble compounds. Barium carbonate is used
as rat bait. (Insoluble compounds, eg barium sulphate, are harmless and used in
barium meal given before X-raying digestive system.) Is an irritant poison,
which causes vomiting and thus can get rid of the fatal dose. Symptoms
Vomiting. Increased pulse and raised blood pressure. Also attacks central
nervous system. Death by heart failure or paralysis. Post-mortem appearance
Inflamed throat, stomach, rectum etc.
- Lead Usually used as one of its salts eg lead acetate. Symptoms are
severe stomach pains, vomiting, coms then death. Repeated small doses can cause
- MercuryMercury salts are used in a wide variety of legitimate
purposes - eg thermometers, paint. Symptoms and fatal doses vary immensely from
type to type.
- Phosphorus Used to be used in matches and rat poison, but no
longer. Yellow phosphorus causes liver damage, delirium then coma.
- Thallium A heavy metal. Salts are colorless, tasteless and easily
dissolved in water. Symptoms easily confused with flu. Works very cunningly - it
confuses to body so it thinks the thallium is in fact potassium, which is vital
for cells and nerves. Symptoms Most distinctive one is hair loss.
Not usually used as murder weapon. Generally only encountered when people
eat them by mistake.
Symptoms of most fungus poisons are sickness, diarrhea and stomach
pains. When you eat them they often taste bitter and burn, telling you not to
eat any further, though some taste delicious (eg Aminita). Then symptoms go away
while the poison spreads through body - by the time any really worrying symptoms
show up, it's really too late. These later symptoms include giddiness, sweating,
fast pulse, anxiety. The more you panic, the faster your heart pumps the poison
round the body.
- Amanita group - Death Cap and Destroying Angel are most deadly - no
symptoms for 12 hours, during which poison spreads, then attacks nuclei of
cells. Fly agaric is a "magic mushroom" used by lots of tribes for
- Ergot Parasitic fungus that grows on rye and other cereal. Used to
get into bread and cause all sorts of problems, including limbs that suddenly
turned black and needed to be amputated. In milder forms, causes tingling at the
extremities. While ergot itself does not contain or produce LSD, as is often
stated, another fungus (often found in close association) turns a substance
which is found in ergot into a hallucinogenic, related to LSD.
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