(59° F.) in 6700 parts of water, in 110 parts of alcohol, in 2500 parts of boiling water, and in 12 parts of boiling alcohol; also soluble in 7 parts of chloroform, but almost insoluble in ether. Dose.-416 grain (0.001-0.004 Gm.).

185.)

Strychnine enters into the following preparations:

Ferri et Strychnine Citras.

Syrupus Ferri, Quininæ et Strychnine Phosphātum. (See Ferrum, page

Strychninæ Sulphas-Strychninæ Sulphātis— Strychnine Sulphate. U. S. P.

Description and Properties.-Colorless or white, prismatic crystals, odorless, and having an intensely bitter taste, perceptible even in highly dilute (1 in 700,000) solution. Efflorescent in dry air. Soluble at 15° C. (59° F.) in 50 parts of water and in 109 parts of alcohol; also soluble in 2 parts of boiling water and 8.5 parts of boiling alcohol. Almost insoluble in ether.

Dose.-6416 grain (0.001-0.004 Gm.).

Antagonists and Incompatibles.-Chloral, tobacco, potassium bromide, chloroform, and ether antagonize the toxic action of strychnine, the first-named drug being the best antagonist. Physostigma, curare, conium, opium, hydrastine, and oil of chamomile are also antagonistic.

The incompatibles are tannic acid, bromides, iodides, and chlorides.

Synergists. The motor excitants, ergot, ustilago, electricity, and cold.

Physiological Action.-Since strychnine fully represents the physiological action of nux vomica, that of the former is here given.

Externally and Locally.-In large doses strychnine acts as an antiseptic, but on account of its poisonous nature it is too dangerous to be serviceable. When applied locally to unicellular organisms, in very dilute solutions, the drug acts as a stimulant, increasing their movements. In slightly more concentrated solutions strychnine arrests these movements and destroys life.

Internally.-Digestive System.-Strychnine is an excellent stomachic tonic, improving the appetite greatly and aiding digestion. By its favorable action upon the mucous membrane of the stomach it facilitates the secretion of gastric juice, and by

imparting tone to the muscular walls of the intestines it increases peristalsis and allays constipation when due to lack of muscular

tone.

Probably the favorable action which strychnine exerts on the stomach is due to its stimulation of the nerve centers which preside over the vascularity and the secretory cells, thus rendering the digestive process more perfect.

Circulatory System.-Strychnine stimulates the heart by its action on the cardiac muscle. Pharmacologically the pulse should

FIG. 5.-Diagram showing how strychnine affects the motor and reflex mechanisms: A, motor and sensory mechanisms; B, cerebral motor areas; C, sensory center; D, motor tract; E, sensory tract; F, spinal motor areas; G, switch center, or mechanism for conveying impressions from sensory to motor nerves; H, sensory nerve; I, motor nerve; K, muscle.

be decreased, owing to the stimulating action of the vagus center in the medulla. But this depressing influence seems to be overcome by the direct stimulating action upon the heart muscle. In therapeutic doses it is generally held that the pulse is slightly increased. In poisonous doses the pulse is slowed and weakened, owing to over-stimulation of both the heart muscle and the motor mechanism.

Nervous System.-Strychnine enormously increases the excita

bility of the central nervous axis. The first symptoms of the drug are an increase in all the reflexes. This has been shown by Holton and Muirhead to be due to a diminished resistance between the cells in the anterior and posterior horns of the cord. Normally, stimulation of a certain part-as, for instance, of a frog's toe-simply occasions a movement of the part stimulated, no other point being affected. But under the influence of strychnine the slightest stimulation is often sufficient to throw the whole body into tetanic contraction, showing that not only is the resistance in the normal path followed by lessened reflexes, but that resistance in all directions is diminished to such an extent that the impulse affects the entire muscular system. This action on the reflexes is solely on the cord. In fact, the action of strychnine upon the cord seems to be more powerful than upon any other portion of the central nervous axis. That the upper brain centers also are stimulated is shown by the fact that all mental processes are rendered more acute; and the same is true of special senses. Very large doses of strychnine cause paralysis of the motor apparatus, with loss of voluntary movement-due to over-stimulation of the reflex centers in the cord, producing

exhaustion.

It must be remembered that strychnine does not increase the automatic powers, but simply augments their susceptibility to external stimulation.

Strychnine greatly intensifies reflex excitability, so that in strychnine-poisoning a bright light, a sound, a jar of the bed, or touching the skin may reflexly produce a convulsive seizure.

Respiratory System.-By the stimulating effect of strychnine upon the respiratory center in the medulla the breathing is rendered quicker and deeper. Owing to the tetanic contractions of the respiratory muscles, under poisonous doses the breathing is greatly interrupted, and the patient may become asphyxiated. At length, the respiratory muscles becoming completely exhausted, death ensues, although the principal cause of collapse is paralysis of the respiratory centre. It is to be noted that the heart continues to beat for some time after respiration has ceased.

Absorption and Elimination.-Strychnine is rapidly absorbed and slowly excreted, and consequently accumulates in the system. It is eliminated mainly by the kidneys, appearing in the urine as strychnine, and is also slightly excreted by the skin and the salivary glands.