An early symptom is a strong metallic taste in the mouth, together with increased salivation. Suppression of urine, hiccough, and dysenteric pain have been reported in a fatal case resulting from external application. Very immoderate doses are attended with rapid and feeble pulse, deathly pallor, severe renal irritation affecting urinary secretion, and final loss of vital power followed by respiratory failure.

The condition induced by prolonged or excessive use of iodine or its salts is known as Iodism. Together with a metallic taste there are present tenderness of the teeth and gums, nausea, and symptoms of gastric irritation.

Marked symptoms involving practically the entire respiratory mucous membrane, coryza, coughing, occasionally dyspnea, etc., this catarrh may extend to the conjunctivae. The skin is always involved - acneiform eruptions - even a vesicular and purpuric variety not unfrequently occurs.

Moreover, muscular twitchings, edema of the glottis, neuralgic pains, and atrophy of mammae, testicles, and other tissues occasionally supervene. Anemia and even cachexia are often manifest.

Treatment of Poisoning. - The use of large amounts of starch, in the form of arrowroot or starch-water, has been successfully adopted as an antidote. Hypodermic injections of ammonia, strychnine, digitalis, alcohol, and atropine have been employed with excellent results, as tending to restore the circulation and assist respiratory movements. More recently bicarbonate of sodium has proved an efficient antidote.

The use of the gastric siphon and the application of heat to the body and extremities are naturally of the first importance.

Therapeutics. - Externally and Locally. - The tincture, compound solution, and ointment are extensively employed as coun-terirritants and as aids to the absorption of fluid. The tincture is an efficient application to joints in chronic rheumatism, goat, and synovitis, and in pleurisy, both for the purpose of aborting an attack and to aid the absorption of fluid when effusion has taken place. In neuritis, onychia, periostitis, venereal bubo, glandular swellings, etc., the tincture, applied externally, will often be of service. Combined with tincture of aconite, equal parts, a useful application to sore gums is secured. The tincture of iodine has been recommended as an efficient application in recession of the gums attendant upon pyorrhea alveolaris.

This same preparation is of marked benefit when hypodermi-cally injected in goiter, particularly of the soft or cystic variety, hydrocele, empyema, extensive serous arthritic effusion unaccompanied by inflammation, spinal meningocele, and anal fistula.

The tincture is also a very efficient application in chronic metritis and chronic endometritis.

In many diseases of the skin iodine serves a useful purpose as a discutient and parasiticide, lentigo, lupus, chloasma, tinea tonsurans, etc.) especially indicating its use.

The vapor of iodine is frequently employed in subacute catarrhal deafness and in acute coryza.

A mixture of tincture of iodine 1/2 fluidrachm (2.0 Cc), carbolic acid 10 minims (0.6 Cc), glycerin and water, each, 1 1/2 ounces (45.0 Cc), has been highly recommended by Samuel Johnston in the treatment of chronic pharyngitis.

As an inhalant in chronic laryngitis and phthisis iodine in some form is highly esteemed by many physicians.

Many iodine substituted derivatives are in active use as antiseptics, (see Antiseptics, Iodoform, etc.).

Internally. - One of the principal and most important uses of iodine and the iodides is in the treatment of secondary and tertiary syphilis. All the manifestations of this disease, such as syphilitic periostitis, meningitis, endarteritis, gummata, paralysis, etc., are relieved by large doses of the iodides to saturation of the system.

Iodine is peculiarly useful in combining with and eliminating mercury from the system of patients suffering from mercurial cachexia, paralysis, etc. Other metals - lead, etc. - are readily eliminated by a course of potassium iodide.

Potassium iodide is of marked utility in arresting the various manifestations of scrofula, such as inflammation and ulceration of cartilaginous structures and mucous catarrhs, and hastening the resolution of adenitis and enlargement of lymphatics.

With regard to the use of iodide in the treatment of aneurism of the aorta Walshe says: "Not only has relief of neuralgic pains and of the general distress followed its administration, but the local pressure-symptoms have been mitigated, and firm thrombosis has taken place within the sac, while the area of pulsation and of per-cussion-dulness has exhibited sensible reduction." Other authorities have reported favorably of its use in this condition.

As cardiac tonics the iodides are of undoubted value, being especially serviceable in fatty degeneration of the heart, and for the mitigation of the symptoms of chronic valvular diseases of the heart, especially those of the aortic orifice. It is a particularly useful remedy in chronic asthma and bronchitis, and to hasten the removal of inflammatory products of pueumonia, pleurisy, and pericarditis.

The spasmodic asthma of adults and the bronchitis of children, both of which alternate with eczematous attacks, are greatly relieved by potassium iodide.

Even hereditary asthma occurs at less frequent intervals and in a milder form when the patient is kept constantly under the influence of moderate doses of this drug.

In the early stages of cirrhosis, whether of the liver or kidneys, potassium iodide is a useful remedy. The dropsy of splenic or hepatic induration is relieved by iodine, while in the various forms of muscular rheumatism it is one of the most potent medicaments. It has been advocated as a successful remedy in sciatica and chronic gout.

Ammonium iodide is highly recommended as an efficient remedy in acute catarrhal pneumonia and capillary bronchitis. It is especially useful in catarrhal jaundice, and has, moreover, been suggested as a good remedy in hay fever.

The syrup of hydriodic acid has been commended by Craig as a valuable agent in acute rheumatism. Small doses of the tincture of iodine have been found efficient in the vomiting of pregnancy.

Contraindications. - The drug should be discontinued at once when symptoms of iodism appear. It is contraindicated also in pulmonary tuberculosis when there is a rapid change taking place in the lung. The iodides should not be given immediately before or after the administration of quinine.

Administration. - The sodium iodide is less active and toxic than the potassium salt. The strontium iodide may be used for the same purpose as the other iodides, and possesses the advantage of disturbing the stomach less, besides being less likely to produce iodism.

The iodides should be given in a large quantity of liquid. Their unpleasant taste may be concealed to a considerable extent by dissolving them in carbolic-acid water or Vichy water. Milk, compound syrup of sarsaparilla, and current and raspberry syrups have all been used for this purpose.

It is said that tincture of belladonna or sodium bicarbonate prevents the coryza caused by the iodides.

The syrup of hydriodic acid is more pleasant to the taste, and has but little tendency to produce iodism or untoward effects. This preparation should always be administered upon an empty stomach. The syrup of the iodide of wine is a useful combination in the cachexia of syphilis.