Iodide of Potassium. KI. Called also the Ioduret of Potassium, and Hydriodate of Potash. Comp. 1 Eq. Iodine=127 +1 Potassium=39=166, Eq. Wt

Med. Prop. and Action. Are closely analogous to those of Iodine. Like it, it occasionally produces headache, flushing of the face, and gastric irritation; and when taken in too large doses, it produces coryza, and, in some cases, salivation and emaciation of the testes and mamma, but these latter effects are rare. M. l)orvault,|| who has examined closely the action and properties of the Iodides, observes, that if the animal fluids (blood, lymph, semen, and milk), or their proteine elements (albumen, fibrin, and casein) be subjected to the action of a solution of Iodide of Potassium, it will bo seen to prevent their coagulation, and will dissolve them. In producing this effect, the salt remains unaltered; it acts, therefore, by what chemists have called the catalytic force. The same result may be shown to have been obtained, when employed in certain pathological cases. The salt may be detected unaltered in the blood, or urine, or other secretions. These facts have been observed by many other investigators, and all have found practically, that the Iodide of Potassium promotes secretion, and increases the function of the mucous glands of the alimentary canal, of the liver, kidneys, skin, pancreas, parotid, &c. It is rapidly eliminated from the animal fluids. Dr. Scharlau found that a patient to whom he gave 53 grammes daily, eliminated 51 by his urine; the other two by the saliva, sweat, and tears. Dr. Kramer satisfied himself by his experiments, that six days sufficed for the complete elimination of this salt, after its exhibition during fifty days. At a lactifuge, the Iodide is stated by M. Roussct* to prove very effectual. In order to obtain this effect, it requires to be given in full doses, within the first or second day after delivery. According to Mr. J. Paget, the addition of Ammonia to the Iodide greatly increases its power. The dose has been a matter of dispute; some exhibiting it in very small doses (gr. ij. - iij.), whilst others have given as much as gr. lx., or even gr. cxx. for a dose. I have invariably observed, that if gr. iij. - iv. thrice daily fail to produce benefit, larger doses were equally ineffectual. All the advantages to be expected from the remedy, will be derived from gr. xij. - xv. daily. Opium appears to interfere considerably with the development of its action. Externally, it may be advantageously applied in the form of ointment. It is mildly stimulant, discolours the skin, and, in some instances, causes much irritation. It should be used freshly prepared, as if kept long it is apt to spoil. (See also Iodum.)

* Lib. of Med., vol. ii. p 270. Brit. and For. Med.-Chir. Rev., Jan. 1849. Lib. of Med., vol i p. 411.

§ Med. Times and Gaz., July 11, 1863. || Iodognosie, Paris, 1852.

Offlc. Prep. 1. Linimentum Iodi (See Iodum.)

2. Tinctura Iodi

(See Iodum.)

3. Unguentum Iodi Compositum

(See Iodum.)

4. Unguentum Potassii Lodidi (Iodide Of Potassium Grs

lxiv.; Distilled Water fl. drm. j.; Prepared Lard oz. j. Dissolve the Iodide in the Water, and mix thoroughly with the Lard).

Vote, gr. j. - gr. v., or more (ante).

Incompatible*. Acids, and the salts of most metals and earths.

2269. Therapeutic Uses

In Scrofula and Scrofulous Affections, the Iodide, given uncombined with other remedies, does not appear to exercise any great influence; but when combined with Iodine, it is essentially useful, and appears to increase the activity of the latter remedy, in addition to rendering it more easily soluble. It should be employed both externally and internally. Lugol found that baths, holding in solution the Iodide alone, produced no sensible effect on the skin, or on the constitution.

2270. In Bronchocele, the Iodide, used externally and internally, proves highly serviceable. Prof. Porta employs a saturated solution of the salt, mixed with lard. From ten to fifteen frictions with this, he states, will be sufficient to judge of its effects; the absorption through the cuticle is perfect. At the same time, he administers the Iodide internally, commencing with gr. viij. daily, and increasing the dose to j. or 3ss., or even 3j. daily. He considers it preferable to the Tincture of Iodine.