Syphilis. in the advanced stage of this affection, iodine is undoubtedly often very serviceable. it is peculiarly useful in that special condition of the disease, characterized by vague pains in the limbs, or, as the patient expresses it, in the bones, with or without periosteal tumours or nodes. We often see this affection, after torturing patients for months, yield with the utmost promptitude to iodide of potassium. in the Pennsylvania Hospital, which receives the sick seamen of the port of Philadelphia, I have constantly encountered this affection, and as constantly seen it yield in the course sometimes of a few days, generally of from two to six weeks, to iodide of potassium, given in the dose of five grains three times a day. it is no doubt also often adequate to the cure of the eruptive and ulcerative affections of secondary syphilis; but here its influence is less certain, and it will generally be found to operate most effectually with the aid of mercury; the auxiliary being, in my apprehension, the most efficient agent of the two. in iritis it is considered by some, when given in the form of iodide of potassium, as second only to mercury, if it be not equal to that medicine in efficiency.

Rheumatism, both chronic and neuralgic, sometimes yields happily to iodide of potassium. It has seemed to me to be specially efficacious in those vague rheumatic pains, resembling the affection just treated of as constituting one of the features of old cases of syphilis. I have often seen it effectual in such instances, when there was no reason to suppose that the affection was in any way connected with that disease. It may be tried in other forms of rheumatism, among the alterative remedies to which we are often driven, one after another, by the obstinacy of the complaint, and the impatience of the sufferer; and sometimes, almost unexpectedly, it will seem to do much good; but it cannot be depended on.

A case of atrophic muscular paralysis was successfully treated by Mr. F. Taylor, of Woodstock, England, with iodide of potassium, given in doses of five grains three times daily. The disease affected both the upper and lower extremities, and finally the face, and was attended with great atrophy of the muscles, but without any loss of sensibility. In about two weeks from the commencement of the treatment, the patient could sit up in bed, in a few days more could walk with the aid of sticks, and in two months was quite restored to health. {Med. T. & Gaz., July 11, 1863, p. 37.)

Chronic cutaneous eruptions are also among the complaints in which iodine is often used as an alterative. Though much less effectual in these complaints than either arsenic or mercury, it sometimes appears to be useful, and may be resorted to in connection with the other alteratives mentioned, or in cases in which they may be forbidden. But more may be expected from the topical application of iodine, in these affections, than from its internal use. It may be employed, according to varying circumstances, in the form of a bath, of a lotion, or an ointment. There are few local applications more efficacious, in chronic skin diseases, than the ointment of iodide of sulphur. I consider it second only to the tar ointment. When the affection is very general, the iodine bath may be preferred. In strictly local cases, the tincture of iodine will often be found extremely effectual, sometimes putting an immediate end to the complaint. It requires, however, to be used with caution, when the eruption is a mere symptom of a constitutional affection. Of the great use of tincture of iodine in superficial inflammation, I shall have occasion to treat in another place.

In poisoning from mercury and lead, particularly the latter, iodide of potassium is an admirable remedy, operating apparently by displacing the metal lodged in the tissues, and then causing its elimination. (See vol. i. p. 153.) Some are disposed to ascribe its efficacy in the form of rheumatism above referred to, connected often with periosteal swelling, to this mode of action; believing that the affection is a kind of mercurial disease. I cannot believe this, until I find proofs, by the discharge of the mercurial by the kidneys, or by the evidence of its peculiar influence vol. ii.-23 on the system, when liberated from its confinement, and admitted into the circulation, that mercury really did exist in the tissues. it has not been my lot to meet with this affection directly traceable to mercury; though few persons have, I presume, in this community, administered it in a larger number of cases than myself. Still, I have no doubt that there are cases of chronic mercurial poisoning, in which the iodide of potassium may be advantageously administered. (See Mercury, page 260.) The medicine has been given, with supposed advantage, in cases of acute mercurialism; and, upon theoretical grounds, it should operate not less efficiently here than in the chronic cases, by eliminating the offending cause, supposing that the whole of the mercurial used has been absorbed, or evacuated from the bowels.

In lead poisoning, it seems, from the reports made in its favour, to be among the most effectual remedies at our command. in these cases, evidence of its efficiency has been given by the appearance of lead in the urine shortly after its employment. it is applicable to the treatment alike of colica pictonum, and the more chronic poisoning exhibited in lead palsy.

Anomalous tumours and ulcers, of an obstinate character, generally offer an indication for the use of iodine. The ulcerative affection of the mouth denominated canker, and those of the surface which accompany ecthyma, rupia, lupus, etc., may often be most usefully treated with iodine, or its preparations, internally or locally, or in the two methods jointly. in that form of alveolar periostitis, which is attended with ulceration about the teeth, and their ultimate loss, it is said to have effected cures. it might even be tried in that fatal affection sometimes taken by man from horses, and usually called glanders. A well-marked case of the disease in a horse is said to have ended favourably, under the tincture of iodine given internally in large doses. it may be used in chronic enlargements of the liver, spleen, uterus, and ovary, and in anomalous tumours forming in the mesentery, with some hope of benefit. it will, in the great majority of these cases, fail to be of any service; but sometimes the swellings disappear under its use, and it deserves a trial in all cases not absolutely desperate. Here it may be used both internally, and by extensive friction over the surface of the abdomen with the ointment. Under the impression of its resolvent powers, it has been recommended in the advanced stages of pneumonia, and in the chronic forms of that disease, when the hepatized or consolidated lung is little disposed to resolution. I have used it occasionally, with doubtful advantage.