Hydrocyanic Acid. (Hydrocyanicum Acidum.)

Prussic Acid. HCy.

Provings by Joerg and pupils, see Allen's Encyclopaedia, vol. 5, p. 1.

Most of the symptoms are toxicological, clinically verified.

- Catarrh of stomach and small intestines, Moore, Allg. Hom. Ztg., vol. 105, p. 46; Chronic dyspepsia, Hendricks, Allg. Hom. Ztg., vol. 105, p. 144; Asthma (3 cases), Frank, N. A. J. H., vol. 8, p. 89; Varicose ulcers on legs, Schssler, Raue's Rec., 1870, p. 330; Nervous exhaustion, Chapman, B. J. H., vol. 7, p. 387; Hysteria, Payne, N. E. M. G., vol. 6, p. 432; Convulsions, Gallagher, N. E. M. G., vol. 4, p. 447; Epileptiform seizures, Cooper, B. J. H., vol. 29, p. 783; Hemiplegia, (benefited), Swan, Hah. Mo., vol. 10, p. 322; Traumatic tetanus, Moore, B. J. H., vol. 24, p. 506.

Inability to think.
Vexed mood, despondency, oppression.
Could not remain in middle of road when he saw a vehicle approaching him even at a considerable distance, but was forced, as it were against his will, to stand aside without waiting for it to come nearer. (After recovering from poisoning).
(OBS:) Insanity, when there is much excitement present, as shown in gesture or speech.
Hysteria. See Chap. 36.

Loss of consciousness.
Dizziness with feeling of intoxication.
Sudden feeling as though everything about him moved slowly; dizzy without reeling; slight pressure left side of occiput over left half of head to frontal region.
Vertigo with reeling; with headache.
Insufficiency of arterial contraction, with frequent headaches, stupefaction and falling down; cloudiness of senses, objects seem to move; he sees through a gauze; is scarcely able to keep on his feet after raising head when stooping, or rising from one's seat, agg. in open air.

Pressure from vertex towards forehead on both sides and to orbits where it became fixed, while from occiput it extended down nape of neck; it caused confusion of head.
Violent pressure in occiput and forehead, agg. right side; pressure soon leaves, but confusion lasts.
Headache with giddiness.
Stupefying headache.
Pricking in various parts of head.
Sudden and desperate cases of cerebro-spinal meningitis; insensibility, with protruded, half open eyes; dilated, immovable pupils, with blindness; roaring and deafness in ears; distorted, bloated and bluish face; tongue paralyzed and protruded; loss of speech; retention of or involuntary urine and stool; rattling, slow respiration; irregular, feeble beating of heart; general coldness with heat in head.
Sudden cerebral congestion, with profound coma; preceded by vertigo, weight and great pain in back of head.

Open eyes, with fixed eyeballs.
Distorted, half open eyes.
Dimness of sight; gauze before eyes.
Pupils dilated, immovable, insensible to light; paralysis of lids; protrusion of eyes.

Roaring and buzzing in ears; hardness of hearing.

Dryness of nose.
Stinging high up in nose, discharge of disorganized, greenish brown looking fetid pieces of hardened mucus.
Enlarged, bluish wings of nose.

Sallow and gray complexion.
Pale, bluish face, looks old.
Face bloated; distorted.
Sudden supraorbital neuralgia, with much flushing of same side of face.

Pale, bluish lips.
Distortion of corners of mouth.
Jaws firmly clenched in rigid spasm.
Froth at mouth.

Taste acrid, sweet or fetid.
Tongue coated white.
Lameness and stiffness of tongue.
Cold feeling of tongue.
Burning on tip of tongue.

Increased secretion of saliva.

Scraping sensation in throat, followed by secretion of mucus in bronchia.
Heat and inflammation of throat.
Drink which is swallowed rolls audibly down throat, as though it were poured into an empty barrel.
Spasm in pharynx and esophagus.
Paralysis of esophagus.

Absence of thirst, with heat of whole body, or violent thirst.

Gurgling noise on drinking, like fluid running into a barrel.

Vomiting of a black fluid.
Acidity and heartburn.

Anguish in pit of stomach.
Great sinking sensation at epigastrium and stomach.
Spasmodic contraction of stomach.
Fluids enter stomach with gurgling noise.
Gastrodynia.
Attacks of indisposition coming on particularly in evening, about two hours after a delayed dinner; during attack refuses all food; intense sourness, sometimes preceded by waterbrash; loss of flesh and depression of spirits. ~ Catarrh of stomach and small intestines.
Burning pain in region of navel, extending to esophagus and throat, two or three hours after eating; loss of appetite; white coated tongue; pyrosis; bitter eructations; flatulency and constipation; region of navel sensitive to touch, and upon deep pressure there is a sensation as of a resistant body; this condition frequently alternates with hepatic disturbance, which manifests itself by attacks of colic; there is also present vomiting of food, or of a slimy, bilious matter, agg. evening and night; emaciation. ~ Chronic dyspepsia.
Intense gastrodynia and enterodynia, with much flatulence, especially when heart sympathizes with the dyspeptic symptoms.
Dyspepsia dependent upon chronic inflammation of stomach and bowels.
Inflammation of stomach and bowels.

Coldness of abdomen alternating with burning.
Cold feeling in abdomen with stitches.
Enteralgia, with distension of abdomen.
Yellow or brownish spots on abdomen.

Involuntary stools, hiccough and great prostration.
Involuntary stool in bed.
Sudden prostration; long lasting fainting spells resembling apoplectic attacks. ~ Cholera Asiatica.
Sudden cessation of all discharges. ~ Cholera.
Rapid progress towards asphyxia; marble coldness of whole body; pulselessness; cessation of vomiting and diarrhea; hiccough; paralysis of esophagus; when drinking, fluid runs gurgling down the esophagus; long fainting spells; trismus; tetanus. ~ Cholera.
Last stage of Asiatic cholera, when diarrhea has ceased and the vomiting has decreased, when there is anguish with pressure on chest, and the patient becomes cold, with gradual extinction of pulse.
Dry cholera.

Uraemia, action of heart diminished; pulse accelerated, soft; stagnation of circulation in heart and lungs; palpitation, with indescribable anguish and dyspnea; depression of sensibility; first convulsions and afterwards paralysis; extreme apathy; slow moaning breathing; rattling in trachea; paralysis of larynx or sudden paralysis of heart. ~ Asphyctic form of uraemia.
Retention of urine.
Copious emission of watery urine.
Involuntary urination.

Gone or sinking sensation in epigastrium, with frequent hot flashes, at climacteric period.

Loss of speech.
Tickling and scraping in larynx and bronchial tubes, with expectoration of yellowish or whitish mucus.
Scraping and burning in larynx.
Sensation as if larynx were swollen.

Noisy and agitated breathing.
Rattling, moaning, slow breathing.
Arrest of breathing caused by stitches in larynx.
Tightness in chest, sensation of suffocation.
Feeling of suffocation with torturing pains in chest.
Asthma, especially when the minute bronchial tubes are chiefly involved, with puffy face and feeble action of heart; or heart's action may be violent.
Periodical asthma, and violent attacks of suffocative, spasmodic cough.
Spasmodic asthma; asthma Millari.

Violent paroxysms of cough, or frequent cough excited by a pricking sensation, which begins in larynx and extends down into trachea, followed by dryness of mouth and larynx; slow, enfeebled and anxious respiration, with much rattling of mucus.
Dry, tickling cough in consumptives, especially if reflex from heart disease.
Nervous cough with dyspnea.
Whooping cough; dry, spasmodic, suffocating cough.

Threatened pulmonary apoplexy.

Heart's action very weak.
Irregular feeble beating of heart.
Heart's action irregular, pulse hardly to be felt.
(OBS:) Palpitation and other functional irregularities of organ, of no very energetic character, whether purely nervous or associated with organic disease.
Sudden outcry; spasmodic sensations; long fainting spells; heart disease with violent palpitations; feeling of suffocation with torturing pains in chest; irregularity of motions of heart; feeble beating of heart. ~ Angina.
Pulse sometimes ceases.
Pulselessness; cold, clammy sweat; involuntary stools; staring, fixed look, with dilated pupils; breathing slow, deep, gasping, difficult and spasmodic, at long intervals; apparently dead.

Brownish spots on chest and abdomen.

Muscles of back and face are principally affected.

Varicose ulcers on legs.

Languor and weakness of limbs.

Lies on bed: with head fixed and thrown backwards, and legs fixed and rigid; no distinct bend backwards or sideways of trunk and leg.
Lies in an apparently unconscious state, limbs and jaws rigid, forearms flexed on arms, which are firmly pressed on side.
Lies like one dead.
Frequently rises in bed, gazes vacantly about for a minute, then throws herself forcibly upon pillow, or flings herself from one side to the other.
Can scarcely stand: after raising head from stooping; on rising from one's seat.
Falls down with vertigo.

General weakness; loss of power; great exhaustion.
Languor and weakness of limbs, especially of thighs.
Long lasting fainting spells.
Nervous exhaustion, the result of overwork and anxiety; loss of appetite; circulation languid; at times is forced to scream out suddenly, she knows not why; this scream is followed by faintness, sometimes even swooning; at such times either before or subsequent to faintness, tightness of chest and acute pain as of spasm of heart; at times is wakened out of sleep by this scream and the overpowering sensations. ~ Nervous dyspepsia.
Lies in an apparently unconscious state, limbs and jaws rigid, forearms flexed on arms, which are firmly pressed to sides; eyes fixed and drawn somewhat to the right; eyeballs slightly sensitive to touch; constant succession of tears roll down cheeks; beat of heart very irregular and feeble; occasionally utters a groan or a sigh, and presses hand forcibly over region of heart, as if suffering pain there; at these times limbs become more relaxed, and she frequently rises in bed and gazes vacantly about for a minute, then throws herself forcibly upon pillow, or flings herself from one side of bed to the other; at times great force has to be exercised to prevent her from injuring herself; if any means are used to extend the contracted arms, or open clenched teeth, she exerts greater power to prevent it; after twenty-four hours this form of attack ceased, and she became very busy packing and folding bedclothes, and placing them carefully under head, or elsewhere about bed, at same time guarding them with watchful eyes, allowing no one to touch or take them; if this is attempted, she strikes with her full strength; seems to notice no person in room, unless they interfere with her plans, but if any one enters, she seizes a pillow or anything within reach, and throws it forcibly at the intruder; at other times fixes eyes on a particular spot on wall, or on a picture, or follows an imaginary figure or object with her eyes, as if watching its motions; frequently talking, laughing loudly, or scolding vehemently; imagines herself surrounded by many friends, shaking hands with them, and calling them by name as they appear before her; she asks no questions and returns no answers; during this time, which lasted four days, she took no nourishment voluntarily. ~ Hysteria.
Anxious feeling and fretfullness; uneasy confusion of head; hysterical spasms; semi-consciousness; limbs and jaws rigid; eyes fixed.
Convulsions when muscles of back, face and jaws are principally affected, and the body assumes a bluish tint.
Convulsions complicated with whooping cough.
Infantile convulsions.
Tonic spasms; catalepsy.
Affects upper spine, especially medulla oblongata; blueness of surface; marked trismus, face blue, threatened suffocation; paralytic weakness quickly developed; water runs down esophagus like through a pipe.
Sudden complete loss of consciousness and sensation; extreme coma for several hours, only interrupted by occasional sudden convulsive movements; confusion of head and vertigo; jaws clenched, teeth firmly set, froth at mouth, forming large bubbles; unable to swallow; involuntary discharge of urine and feces; upper extremities contracted and hands clenched; unusual stiffness of legs; spasms commencing in toes, followed by distortion of eyes, towards right and upwards, afterwards general spasms; distortion of limbs and frightful distortion of face; trunk spasmodically bent forward; great exhaustion, prostration and aversion to all work, mental or physical.
Sudden epileptiform seizures coming on about every three months, lasting for two or three weeks and leaving him completely prostrated; falls down with vertigo accompanied by vomiting of food; lies like one dead; in some attacks the patient remains about for several days, in which case he vomits quantities of green fetid fluid, accompanied by green motions from bowels; during attacks can drink, but cannot eat; lies in a drowsy, semi-comatose state, at times being plunged into convulsions, during which he grinds his teeth.
Epileptic form of hysteria.
Tetanic grin; jaws firmly fixed; masseters hard; lies on bed with head fixed and thrown backwards, and legs fixed and rigid; no distinct bend backwards or sideways of trunk and legs; abdominal muscles firmly contracted and hard as a board, severe spasms of all muscles, during which breathing becomes hurried and labored, agg. at night, when dropping off to sleep; feels on verge of suffocation; can hardly be kept in bed; paroxysms come on without any apparent provocation and leave him prostrate with exhaustion and apprehension; dreads their approach, and cannot sleep for fear of these attacks seizing him just as he closes his eyes; has not slept for several days; fluids can be swallowed when poured into mouth, but the act is painful and difficult; pulse 80; constipated. ~ Traumatic tetanus.
Cyanotic appearance; cold; heart beats slower and slower, until it almost ceases, then suddenly rises in frequency, with each return of spasms. ~ Tetanus.
Traumatic tetanus.
Tetanic convulsions during course of diarrhea and dysentery.
General coldness, long lasting syncope; anguish and pressure on chest; hiccough; rattling, moaning, slow breathing; distorted features; pupils dilated; eyelids paralyzed; filiform pulse. ~ Shock.
Darting pains; inability to think; feeling of approaching paralysis; unsteadiness of gait.
Loss of sensation in limbs, with stiffness of same.
Staggering and trembling; immobility; insensibility; stiffness of body.
Paralysis first of lower, then of upper limbs.
Paralysis of left side; could recognize persons, but was unable to speak; intermittent pulse and heartbeat; fingers cold; nose pinched, eyes turned up. ~ Hemiplegia.
Diseases of cerebro-spinal system that come on with great suddenness and severity; mind depressed and very irritable.

Irresistible, constant drowsiness.
Prolonged sleeplessness, or very heavy sleep; fear and great anxiety.

For several hours: extreme coma.
Two or three hours after eating: burning pain in region of navel, extending to esophagus and throat.
For several days: in some attacks the sickness remains; has not slept.
Evening: attacks of indisposition; two hours after delayed dinner; vomiting of food or slimy, bilious matter agg.
Night: vomiting of food or slimy, bilious matter; severe spasms of all muscles, during which breathing becomes hurried and labored agg.

Open air: vertigo agg.

Coldness within and without, like marble.
Cold extremities.
Heat in head with coldness of extremities.
Heat and perspiration over whole body.
Body covered with sweat.
Scarlatina, when the eruption in its early appearance is dark colored and soon becomes livid, only slowly regaining its color when this is expelled by pressure of finger; rapid, feeble pulse; coma and great prostration.
Bad cases of small-pox.

Attacks last four days.
At times: is forced to scream out suddenly, she knows not why; tightness of chest; acute pain at heart; is awakened out of sleep by this scream; plunges in convulsions.
About every month: sudden epileptiform seizures lasting for two or three weeks.

Right: side of head violent pressure.
Left: slight pressure of occiput over left half of head to frontal region, paralysis of side.
Towards right and upwards: distortion of eyes.

As though everything about him moved slowly; as if drink was poured down throat like an empty barrel; as if a resistant body in region of navel; as if larynx was swollen.
Torturing pains: in chest.
Acute pain: of heart.
Great pain: in back of head.
Darting pains: general.
Stitches: in abdomen; in larynx.
Anguish: in pit of stomach; in chest.
Stupefying headache.
Supraorbital neuralgia.
Stinging: high up in nose.
Burning pain: in region of navel.
Burning: on tip of tongue; on larynx.
Scraping sensation: in throat; in larynx; in bronchial tubes.
Pricking sensation: from larynx to trachea.
Pricking: in various parts of head.
Tickling: in larynx.
Violent pressure: in occiput and forehead.
Slight pressure: left side of occiput over left half of head to frontal region; from vertex towards forehead on both sides and to orbits, where it became fixed, while from occiput it extended down nape of neck.
Heat: in head; in throat.
Confusion: of head.
Gone sensation: in epigastrium.
Weight: in back of head.
Tightness: in chest.
Stiffness: of tongue; of legs.
Lameness: of tongue.
Weakness: of limbs.
Dryness: of nose; of mouth; of larynx.
Roaring and deafness: in ears.
Buzzing: in ears.
Coldness: in body.
Cold feeling: of tongue; of abdomen.

Acts upon cerebral veins, producing congestion; secondarily upon heart, nerves, etc.

Touch: region of navel sensitive; eyeballs slightly sensitive.
Pressure of finger: scarlatina, when eruption, in its early appearance, is dark colored and soon becomes livid, only slowly regaining its color when this is expelled by pressure of finger.

Paleness with a blue tinge.
Dryness of skin.
Itching; formication; erythema.

Boy, aet. 3; epileptiform seizure.
Joiner, aet. 20, after scalding legs; traumatic tetanus.
Married woman, aet. 23, after undergoing the most heroic treatment, even to trephining, two months after abortion; hysteria.
Woman, aet. 30, drawing teacher; nervous exhaustion.
Man, aet. 39, bilious temperament, dark complexioned, married; catarrh of stomach and small intestines.
Woman, aet. 80; hemiplegia (benefited).

Antidoted by: Ammonia, Camphor., Coffea, Ipec., Nux vom., Opium, Verat. viride.
Compare: Camphor. (first stage of cholera); Acon., Cicuta (action on spinal cord); Oenanthe crocata (in epilepsy).