In all the local affections above enumerated, as requiring the constitutional impression of iodine, it may also be applied topically, in some one of the various forms which will be described among its preparations. in these cases, the object of the local employment of the remedy is to aid in obtaining its alterative influence, through the constitution, upon the diseased tissue. But iodine is often also used with a view exclusively to its local effect. This may be considered as simply irritant, or as jointly irritant and alterative. Another principle upon which the medicine operates locally, especially when the tincture is employed, is so to affect the epidermis, as to exclude the influence of the air; but more will be said on this point hereafter. in one or more of these methods, it is very useful in various cutaneous eruptions, for rendering the eruption of small-pox abortive, in chronic inflammation of the fauces, in chronic enlargement of the tonsils, in strumous inflammation of the eyes, in which it is applied to the lids, and in various superficial cutaneous inflammations, as erysipelas, chilblains, scalds, burns, etc. in subcutaneous inflammations also, of various character, it has been used with more or less advantage; as in ordinary phlegmon and furuncles, swollen bursae, paronychias, swellings about the small joints, and even in more serious affections, such as external inflammatory swellings about the larger joints, whether ordinary or rheumatic, gouty inflammation, etc. The same treatment has been extended to large serous accumulations, as hydrocele, ovarian dropsy, and even ascites; and it is not uncommon at present to use iodine externally as a rubefacient in internal inflammations, as laryngitis, bronchitis, pleurisy, peritonitis, etc., in the very commencement, or in their advanced stages. in all these cases, it is the tincture that is employed; and this is applied to the outer surface. (See the article on Protectives.) The injection into the uterus of tincture of iodine, diluted with twice its bulk of water, has been used, with great asserted success, by M. Dupierris, of Havana, Cuba, in uterine hemorrhage; the remedy having failed only in one out of one hundred cases. (N. Am. Medico-chir. Rev., i. 95.) inunction with the ointment of iodine has proved serviceable in lead palsy.

Another local use made of iodine is to change the condition of secreting serous surfaces by direct contact, so as to obviate the tendency to excessive secretion. For this purpose, one of the tinctures, more or less . diluted, is injected into the serous cavity. in this way, iodine has been used happily for effecting the radical cure of hydrocele and ovarian dropsy; and the idea has been practically extended to the pleural and peritoneal cavities, and those of dropsical joints. Considerable success has been claimed for this treatment in empyema. it has also been employed in abscesses, acute or chronic, indisposed to heal, in fistula in ano, and in serous cysts and hydatids. For the modes of using the tincture in these cases, see Tincture and Compound Tincture of iodine.

The local use of the tincture of iodine has proved serviceable in troublesome inversion of the eyelids, being applied daily to the outer surface of the lid, and operating probably by giving tone to the underlying muscles. A similar result has been obtained in falling of the upper lid. (A. Carr, Lancet, Am. ed., Nov. 1858, p. 366.)

Marchal de Calvi considers the compound solution of iodine almost as a specific in that peculiar affection of the gums, generally suppurating, ulcerous, or fungous, which causes the loss of the teeth. He applies it dissolved in water to the diseased tissue, first employing a weak solution, such as was used by Lugol for baths, and gradually making it stronger until very concentrated at last. (Ann. de Thérap., 1861, p. 236.)

Dr. D. Brainard, of Chicago, suggested the local use of iodine as an antidote to the poison of serpents, having found woorara, which he supposed to contain poison extracted from serpents, to be neutralized and rendered inert by admixture with iodine. The plan was to apply a cupping-glass over the wound, and then to inject into the tissues around it, through minute incisions, an aqueous solution of iodine with iodide of potassium, so as completely to infiltrate the tissue. (Essay, etc., Chicago, 1854.) Dr. E. Harwood, in a communication to the N. W. Medical and Surgical Journal, states that he applied the tincture of iodine in a case of snake-bite in 1848, with success, and has since employed it in another case with the same result. He simply applied the tincture by means of a camel's-hair pencil. {Boston Med. and Surg. Journ., 1. 328.)

Still another topical application of iodine is the inhalation of its vapour in chronic inflammation of the bronchial tubes. it has even been recommended in this way as a remedy in phthisis; but a moment's consideration will convince a reflecting physician, acquainted with the real condition of the lungs in this disease, of the utter inadequacy of iodine, or any other known inhalation, to make a serious impression upon it. The most that can be expected is a favourable modification of the attendant laryngitis or bronchitis; and there is probably more danger of injurious irritation than probability of benefit in the case. But in pure chronic laryngitis or bronchitis, the inhalation may be tried with the hope of benefit. it may prove useful in aphonia also, whether arising from debility or chronic inflammation of the mucous membrane. The preparation generally used for the purpose is the compound solution of iodine, to which the reader is referred.

Contraindications to the use of iodine are offered by high febrile excitement, acute inflammation with fever, and gastritis.