Digitalis in full doses produces a great rise in arterial pressure, followed by a marked fall. It acts on the inhibitory nerves and on the heart muscle; the increased action being due to vasomotor spasm and to stimulation of the heart itself. A poisonous dose causes depression and a dicrotic pulse, while the immediate effect of moderate doses is to stimulate the heart. Its prolonged use weakens the heart muscle by decreasing its normal nutrition

Digitalis is the direct heart stimulant. Its influence is sure and plainly apparent in marked sthenic conditions. In prostration or profound weakness, in sudden failure from violent injury, from surgical shock or from acute poisoning, or in the crisis of extreme exhausting or protracted disease, its influence given in conjunction with general stimulants is decisive and satisfactory.

The influence of digitalis in its stimulant effect is nearly diametrically opposed to that of aconite. In therapeutic action the two agents occupy the opposite extremes. For this reason digitalis, within the limits of its stimulant action, is a physiological antidote to aconite.

Foxglove is a handsome biennial plant,

Foxglove is indigenous to the larger portion of Europe,

It has been naturalized in the Isle Chiloe of South Chili (Cunningham).

The official part is the leaves, though the seeds will also be found efficient.

The seeds, though but little used, retain their properties much better than the leaves.

In single large doses, digitalis is an irritant-narcotic poison, producing gastro-intestinal irritation, nausea, vomiting, and very abundant alvine evacuations. Its action is afterward spent upon the nervous system, causing vertigo, dimness of sight, delirium, convulsions, or a general debility, and finally death

When given in medicinal doses, too long continued, or in quantities to exert an immediate action on the system, it causes an increased discharge of urine, reduces the pulse from 70 beats in a minute to 30, with languor, nausea, occasionally anxiety and salivation, a sense of weight, or constriction, obtuse pain in the head, giddiness, disordered vision, mental disturbance, and rarely spectral illusions; not unfrequently a huskiness of the voice is present, the result of irritation of the fauces, trachea, etc. The nausea produced by digitalis, and more quickly by digitalin and digitoxin, is preceded by malaise, faintness, and depression, and is exceedingly distressing.

Primarily, digitalis acts upon the heart as a stimulant, increasing the tension and pulse rate; larger doses, acting as a sedative, reduce the pulse, but the tension remains unaffected. The diastole is prolonged while the systole is increased in vigor. A lethal dose produces a tetanic contraction of the heart muscle, particularly of the left ventricle, the heart being arrested in systole. The effect of the stronger systole and the prolonged diastole is a reduction of the number of pulsations. Not only does a contraction of the heart muscle take place, but a marked contraction of the arterioles also results, so that the blood current is reduced in size and the amount of blood sent through the arteries to the different parts of the system is decreased.

Poisoning by digitalis may be produced by 1/16 grain of digitalin (equal to 8 grains of good powdered digitalis leaves)

The poisonous effects of digitalis are best counteracted by first evacuating the stomach by the free use of warm liquids and mechanical emetics, if any of it is supposed to remain in the stomach, and then administering brandy, wine, opium, black coffee, ammonia, ammonium carbonate, or other stimulants, with sinapisms to the wrists and ankles. Both external and internal heat should be used. A solution of tannic acid might be of service, by forming an insoluble tannate of digitalin. Preparations containing tannin, such as tea, etc., may be given. Iron sulphate and chloride are recommended by some as chemical antagonists. Digitalin produces similar effects on the system with digitalis, but its internal administration is hazardous, and demands much care and prudence. After death from digitalis the gastric membranes were found partially inflamed and the meninges of the brain much injected (Taylor).

SOURCE.—The plant is indigenous to Southern and Central Europe, particularly in the western section, and grows wild as far north as Norway, also in Madeira and the Azores, and is cultivated in the United States. It is found on the edges of woody land and prefers sandy soil.

ADULTERATIONS.—Other dried leaves are sometimes mixed with digitalis, the commonest of these are: Inula conyza (Conyza squarrosa), spikenard, and Inula helenium, both having entire, instead of crenate or serrate, margins, and the latter having its veins branching off at about right angles to the midrib, accidental impurities, such as Comfrey leaves, Symphytum officinale, have been found. These are lanceolate and bear isolated stiff hairs.

Much of the leaf found in our shops is of very poor quality, a large proportion being inert; but whether this is due to our Phar. not restricting the official drug to the wild plant, or to careless treatment in gathering and drying, is not definitely known. When, however, the leaves are imperfectly dried, a process of decomposition sets in which destroys the active principles, and may produce new and poisonous ones. A similar decomposition is said to occur whenever the tincture of Digitalis is mixed with watery or syrupy solutions. Certain it is, at any rate, that Digitalis is one of the most unreliable drugs, in respect of the physiological activity of any particular sample or preparation. The seeds are known to contain the active principle in much greater proportion than the leaves, but they are never used.

It was used in domestic medicine in early days, and by the Welsh (see note, page 8) as an external medicine. Fuchs (252) and Tragus (650), 1542, pictured the plant, but remarked that it was a violent medicine. Parkinson (492) commended it in 1640, and it was investigated in 1776-9 by Withering (693), through whose efforts it was introduced into licensed medicine. Digitalis was originally employed as a remedy in fevers, in which direction it is no longer used. In 1799, J. Ferriar (233), of Manchester, England, contributed a treatise concerning the medicinal uses of this drug, which was also described by Withering (693), Bosch (89), Moore (450), and other authors of that period. At present it is largely valued for its poisonous action and is by some standardized by its physiological qualities when injected into the veins of lower animals, the United States Government having issued a bulletin on the subject.

In the treatment of pneumonia, in the early stages, it is my custom to prescribe specifically in accordance with the indications found, as taught by most of our writers. This method does not usually find a place for digitalis in the early stage of the disease. I think I have found a specific indication for digitalis in the later stages.

I have treated fifty-seven cases in the Williamsport Hospital that were apparently in the last stage of the disease, where the breathing was very rapid and short, where the pulse was so rapid that it could not be counted, where the respiratory distress was very pronounced, and where the skin, especially that of the face and neck, was distinctly cyanosed. The skin was cold, and often there was a cold perspiration. I gave these a concentrated tincture of digitalis, with the very best of results, upon the above indications. To adults I have given fifteen drops every two hours, to children I have given ten drops every two hours, and have seen no toxic or cumulative influence. Fifty-five out of the above fifty-seven cases recovered.

Mind.--Despondency; fearful; anxious about the future. Dullness of sense. Every shock strikes in epigastrium. Melancholia, dull lethargic with slow pulse.
Head.--Vertigo, when walking and on rising, in cardiac and hepatic affections. Sharp, shooting frontal pain, extending into nose, after drinking cold water or eating ice-cream. Heaviness of head, with sensation as if it would fall backward. Face bluish. Confusion, fullness and noise in head. Cracking sounds during a nap. Blue tongue and lips.
Eyes.--Blueness of eyelids. Dark bodies, like flies, before eyes. Change in acuteness of perception of shades of green. Objects, appear green and yellow. Mydriasis; lid margins red, swollen, agglutinated in morning. Detachment of retina. Dim vision, irregular pupils, diplopia.
Stomach.--Sweet taste with constant ptyalism. Excessive nausea, not relieved by vomiting. Faintness, great weakness in stomach. Burning in stomach extending to oesophagus. After cold water or ice-cream, sharp pain in forehead, extending to nose. Faintness and vomiting from motion. Discomfort, even after a small quantity of food, or from mere sight or smell. Tenderness of epigastrium. Copious salivation. Neuralgic pain in stomach, unconnected with taking food.
Abdomen.--Pain in left side apparently in descending colon and under false ribs. Severe abdominal pains, pulsation in abdominal aorta, and epigastric constriction. Enlarged, sore, painful liver.
Stool.--White, chalk-like, ashy, pasty stools. Diarrhoea during jaundice.
Urine.--Continued urging, in drops, dark, hot, burning, with sharp cutting or throbbing pain at neck of bladder, as if a straw was being thrust back and forth; worse at night. Suppressed. Ammoniacal, and turbid. Urethritis, phimosis, strangury. Full feeling after urination. Constriction and burning, as if urethra was too small. Brick-dust sediment.
Female.--Labor-like pains in abdomen and back before menses. Uterine haemorrhage.
Male.--Nightly emission (Digitalin), with great weakness of genitals after coitus. Hydrocele; scrotum enlarged like a bladder. Gonorrhoea, balanitis (Merc), with oedema of prepuce. Dropsical swelling of genitals (Sulph). Enlarged prostate.
Respiratory.--Desire to take a deep breath. Breathing irregular, difficult; deep sighing. Cough, with raw, sore feeling in chest. Expectoration sweetish. Senile pneumonia. Great weakness in chest. Dyspnoea, constant desire to breathe deeply, lungs feel compressed. Chronic bronchitis; passive congestion of the lungs, giving bloody sputum due to failing myocardium. Cannot bear to talk. Haemoptysis with weak heart.
Heart.--The least movement causes violent palpitation, and sensation as if it would cease beating, if he moves (Opposite; Gels). Frequent stitches in heart. Irregular heart especially of mitral disease. Very slow pulse. Intermits; weak. Cyanosis. Inequality of pulse; it varies. Sudden sensation as if heart stood still. Pulse weak, and quickened by least movement. Pericarditis, copious serous exudation. Dilated heart, tired, irregular, with slow and feeble pulse. Hypertrophy with dilatation. Cardiac failure following fevers. Cardiac dropsy.
Extremities.--Swelling of the feet. Fingers go to sleep easily. Coldness of hands and feet. Rheumatic pain in joints. Shining, white swelling of joints. Muscular debility. Nocturnal swelling of fingers. Sensation in legs as if a red hot wire suddenly darted through them (Dudgeon).
Sleep.--Starts from sleep in alarm that he is falling from a height. Continuous sleepiness.
Fever.--Sudden flushes of heat, followed by great nervous weakness.
Skin.--Erythema, deep red, worse on back, like measles. Blue distended veins on lids, ears, lips and tongue. Dropsical. Itching and jaundiced.
Modalities.--Worse, when sitting erect, after meals and music. Better, when stomach is empty; in open air.

The leaves, especially those offered in the crushed or powdered state, are occasionally adulterated, leaves of the following plants being liable to be substituted or mistaken for the true drug:—Mullein leaves (Verbascum Thapsus, Linn.), which are woolly, and have branched hairs; comfrey leaves (Symphytum officinale, Linn.), lanceolate, with isolated stiff hairs; primrose leaves (Primula vulgaris, Huds.) which are spathulate, and have straight lateral veins; ploughman's spikenard leaves (Inula Conyza, D C.), with an entire or dentate margin, the teeth bearing horny points. Matico leaves (Piper angustifolium, Ruiz and Pay.) are distinguished by the depressed veinlets on the upper surface.

Cardiac tonic and stimulant and diuretic. It slows the heart's action and increases its force,

Needing little soil, it is found often in the crevices of granite walls, as well as in dry hilly pastures, rocky places and by roadsides. Seedling Foxgloves spring up rapidly from recently-turned earth. Turner (1548), says that it grows round rabbitholes freely.

The plant will flourish best in welldrained loose soil, preferably of siliceous origin, with some slight shade. The plants growing in sunny situations possess the active qualities of the herb in a much greater degree than those shaded by trees, and it has been proved that those grown on a hot, sunny bank, protected by a wood, give the best results.

It grows best when allowed to seed itself, but if it is desired to raise it by sown seed, 2 lb. of seed to the acre are required. As the seeds are so small and light, they should be mixed with fine sand in order to ensure even distribution. They should be thinly covered with soil. The seeds are uncertain in germination, but the seedlings may be readily and safely transplanted in damp weather, and should be pricked out to 6 to 9 inches apart. Sown in spring, the plant will not blossom till the following year. Seeds must be gathered as soon as ripe. The flowers of the true medicinal type must be pure, dull pink or magenta, not pale-coloured, white or spotted externally.

Digitalis

Bolster'd with down, amid a thousand wants,
Pale Dropsy rears his bloated form, and pants;
"Quench me ye cool pellucid rills," he cries,
Wets his parched tongue and rolls his hollow eyes.
So bends tormented Tantalus to drink
While from his lips the refluent waters shrink;
Again the rising stream his bosom laves
And thirst consumes him mid circumfluent waves.
Divine Hygeia from the bending sky
Descending, listens to his piercing cry;
Assumes bright Digitalis dress and air;
Her ruby cheeck, white neck and rraven hair;
Four youths protect her from the circling throng,
And like the Nymph the Goddess steps along,
O'er him she waves he serpent wreathed wand,
Cheers with her voicce and raises with her hand
Warms with rekindling bloom his visage wan,
And charms the shapeless monster into man.