(Spotted Hemlock.)

Origin. - The full-grown but unripe fruit of Conium maculatum L., carefully dried and preserved, and yielding when assayed not less than 0.5 per cent. of coniine. After being kept for more than two years conium is unfit for use. Spotted hemlock is a biennial indigenous herb, a few feet high, growing in the temperate regions of Asia, Europe, and Northern Africa, and naturalized in some portions of New England, New York, and South America. It grows in waste places and along streams.

Description and Properties. - About 1/8 inch (3 Mm.) long, broadly ovate, laterally compressed, grayish-green, often divided into two mericarps, each with five crenate ribs, without oil-tubes, and containing a seed grooved on the face; odor and taste slight.

When triturated with solution of potassium or sodium hydrate conium gives off a strong, disagreeable, mouse-like odor.

The most important constituent is a volatile liquid alkaloid, coniine. It also contains methyl-coniine, conhydrine, and its isomer pseudo-conine. The volatility of the alkaloid is largely responsible for the varying composition of the preparations and the discordant therapeutic results.

Dose. - 1-5 grains (0.06-0.3 Gm. [3 grains (2 Gm.), U. S. P.],

Official Preparation

Fluidextractum Conii - Fluidextracti Conii - Fluidextract of Conium. - Dose, 1-5 minims (0.06-0.3 Cc.) [3 minims (0.2 Cc), U. S. P.].

Coniine is closely related to piperidine; its structural formula is that of propyl piperidine.

Antagonists and Incompatibles. - Nux vomica and its alkaloids, cocculus and picrotoxin, are antagonistic to conium. Tannic acid and the alkalies are chemically incompatible.

Synergists. - The motor depressants and morphine.

Physiological Action. - Externally and Locally. - Coniine, the active principle of conium, has no effect upon the unbroken skin.

Internally. - Digestive System. - Conium increases the salivary-secretion, and when taken into the stomach exerts no special action upon the digestive system other than an occasional disturbance of the gastro-intestinal tract, possibly resulting in vomiting and diarrhea under full dosage.

Circulatory System. - Although when ingested coniine is rapidly absorbed by the blood, circulating in the system unchanged, its action is not clearly defined, though it has been held that the circulation is first accelerated and then retarded, with a lowering of arterial pressure preceded by a decided increase.

From its capacity to paralyze the vagi terminals it is natural to suppose that it increases the rapidity of the cardiac movements, yet a characteristic feature of the absorption of coniine is the apparent absence of cardiac derangement, the heart, as well as the mind, remaining unaffected in the presence of alarming symptoms.

Nervous System. - The action of coniine in the higher cerebral centers is very slight. In some patients a mild drowsiness has been observed, but, as a rule, consciousness and the thought processes are not modified, save in the final stages of asphyxiation. The action on the medulla is also slight.

Spinal Cord and Motor Ganglia. - The action on the cord is not determined. Slight twitchings and even convulsions are sometimes observed, but it is not positive that central irritation is the cause.

The characteristic action of conium is on the terminal end-plates in the voluntary muscles. These are paralyzed after a possible transitory stimulation. Some depression of motor-plates in involuntary muscles is also noted, particularly in the heart, but it is not as pronounced as in the plates of the voluntary muscles.

Respiratory System. - Large or poisonous doses may depress the respiratory center, but paralysis of the muscles of respiration is probably responsible for death rather than poisoning of the centers.

Absorption and Elimination. - The drug is readily absorbed. Elimination is rapid and takes place chiefly through the kidneys and lungs. Coniine has been detected in considerable quantities in the liver, lungs, and spleen.

Temperature. - It has been held that bodily temperature is perceptibly lowered by conium, proportionately with the extent of the paralysis occasioned. High authorities, however, assert an increase of temperature under both therapeutic and toxic doses.

Eye. - Heaviness of the eyelids, dilated pupils, accompanied by double or confused vision and occasionally entire loss of sight, have been noted among the symptoms incident to the administration of active dosage. The paralysis of the third nerve is probably responsible.

Poisoning. - A frequent symptom of conium-poisoning is ptosis, arising from paralysis of the oculomotor nerves. Staggering gait, general muscular relaxation, impairment of vision, nausea, and vertigo are also not infrequent. The severer symptoms are marked by-muscular paralysis of the extremities, derangement of vocal organs resulting in difficulty of speech, and dilatation of the pupils. The brain meanwhile remains unaffected until overcome by the accumulation of carbon dioxide gas in the blood, when delirium and coma may ensue, and finally cerebral convulsions and fatal collapse through respiratory failure. Doses of 2 gr. (0.15 gm.) conium have caused death within a half hour. Socrates is said to have died in 40 minutes after taking the poisoned cup.

Treatment of Poisoning. - The stomach should be evacuated by means of emetics or lavage, after which tannic acid and the physiological antidotes may be administered. Artificial respiration is practically the only expedient, as the paralyzed end-organs cannot physiologically respond to any drug irritation.

Therapeutics. - Externally and Locally. - Conium leaves applied as a poultice relieve pain somewhat, as in ulcers and carcinoma, but other and better local analgesics are at hand, and its use in this respect is limited.

It is very problematic whether conium has any well-marked therapeutic applications. If it is employed, it is absolutely essential that a very fresh specimen be used, since the active alkaloid is volatile. It is perhaps best to use a salt of the alkaloid or a salt of methyl-coniine. On theoretical, as well as practical, grounds it can have little value in the involuntary spasmodic affections; it can only mask muscular movement, not modify the pathological impulses. In voluntary habit spasms, however, it has its only practical uses. Here it may prevent the accomplishment of a morbid muscle impulse, and thus with suggestive therapeutics be of service in the treatment of the habit "tics," habit spasms, etc., particularly in their early stages. When the brain path is firmly established conium is of little service.

Contraindications. - Conium should not be given to persons suffering from great exhaustion and debility or from diseases interfering with the rhythm of the heart.

Administration. - The preparations of conium are very unreliable, the assayed, or "standardized" fluid extract being perhaps the one to be depended upon most uniformly. Owing to the uncertainty of their strength, the administration should begin with small doses gradually augmented until interference with involuntary motion is observed, when further increase should be stopped.

The effects of the drug are weakened by repeated doses, rendering an increase in the dose necessary from time to time. Coniine and morphine greatly aid each other, and this combination is a particularly efficient one in the treatment of painful muscular spasms and acute mania with excessive motor activity. Conium and sulphonal are of great value in insomnia accompanied by motor restlessness. (See Sulphonal.)