Preparation and Properties. Chlorinated lime is made by exposing hydrated or slaked lime to the action of chlorine, continued until the lime will absorb no more. it is a whitish powder, of an odour resembling that of chlorine, yet somewhat different, and a strong, bitter, acrid, and astringent taste. When the lime is accurately saturated, the compound is said to be wholly soluble in water; but it is seldom if ever met with in this state; always probably containing more or less carbonate of lime, which, with a portion of the hydrate of lime, is left behind when the salt is dissolved. On exposure to the air, it slowly absorbs carbonic acid, giving out its characteristic odour. The acids generally cause the evolution of chlorine, by combining with the lime. The alkaline carbonates throw down carbonate of lime from its solution. it has the property of evolving oxygen, or of causing its evolution by abstracting hydrogen from water, thus operating, like chlorine, as a decolorizing and disinfecting agent; the oxygen, in its nascent state, combining with and destroying the colouring and putrescent principles.

Nature. Different views are entertained of its chemical nature. The simplest is that which considers it merely as a compound of lime and chlorine, held together by feeble affinities. According to another, and the most common view, it is a mixture of hypochlorite of lime and chloride of calcium; the hypochlorous acid being formed by the combination of a part of the chlorine with the oxygen of a portion of the lime, and then combining with the undecomposed part of the lime, while the liberated calcium combines with the remainder of the chlorine to form the chloride. if this were the correct view, one would suppose that the salt should be deliquescent; as chloride of calcium, which it is presumed to contain, has this property in a high degree. A third opinion considers it an oxychloride of calcium; the metallic base uniting with an equivalent of chlorine in addition to the equivalent of oxygen already combined with it. in this uncertainty as to its precise nature, the officinal authorities have done wisely in adopting a name which expresses simply what happens in its preparation.

Effects on the System

These are compounded of the effects of lime, chlorine, and chloride of calcium. Locally the preparation is in a greater or less degree irritant, corrosive, astringent, disinfectant, and antiseptic; internally it produces the antacid effects of lime, the constitutional impression of chlorine and the chlorides, and the local irritant effect of all its constituents on the alimentary mucous membrane.

Medical Uses

Chlorinated lime has been given in affections, similar to those to which the preparations of chlorine have been thought adapted, especially in typhoid fevers and scrofulous complaints; and it may be employed, with hope of benefit, in cases of offensive personal exhalations, which may be supposed to have their origin in putrefactive changes going on in the alimentary canal; as, for example, in malignant forms of dysentery, in which it may be administered both by the mouth and the rectum. But it is at present little used internally. Topically, however, it is much employed for various purposes.

Notice has already been taken of its use for the extrication of chlorine, for purposes of inhalation and disinfection. The spontaneous evolution of chlorine, which takes place from it under the influence of the carbonic acid of the atmosphere, renders it useful for the latter purpose, even without addition; the moist powder being placed, in shallow vessels, in situations requiring purification, or a solution of it sprinkled in apartments, and over objects, rendered offensive by putrid exhalations. its addition to the close-stool, in cases of offensive discharges, and especially those of bad attacks of dysentery, will tend to obviate ill effects from this source. Though quite ineffective in destroying the cause of epidemic diseases, as yellow fever and cholera, there is some reason to think that it is capable of neutralizing or decomposing certain contagious matters. its supposed effect in preventing hydrophobia has been mentioned. it is said to have a similar effect on the contagion of syphilis and the plague.

Used as a gargle in the gangrenous, ulcerated, or pseudomembranous angina of scarlatina, and in similar affections of the mouth and fauces from other sources, as from mercury, syphilis, scurvy, etc., it is useful not only by correcting the fetor, but also by obviating in some degree the gangrenous tendency, and stimulating the diseased surface into a healthy state. in cases of gangraena oris, the powder itself has been sprinkled on the diseased surface with great asserted advantage. in offensive discharges from the nostrils and ears, whether acute or chronic, the solution may also be injected with good effect. it is thought to have proved serviceable, as a wash for the eyes, in scrofulous ophthalmia.

In sloughing ulcers, sphacelus from burns or other cause, gangrenous abscesses, and offensive suppurating surfaces of whatever kind, the solution of chloride of lime may be applied upon suitable dressings, or injected, as the case may be. it is much used in this way in cancerous sores, and in cancer of the womb, as well as other cases of offensive discharges from the vagina. it may be used also, simply as an alterative local stimulant, in all flabby and indolent ulcers, especially those of scrofulous origin, and those succeeding frost-bite.

In various cutaneous eruptions, the solution is also very serviceable, especially those of parasitic origin, whether animalcular or fungous; as scabies of the former kind, and porrigo and trichosis of the latter. Dr. Christison, who ascribes the first use of the solution in the itch to M. Derheims, states that he has never had occasion to use any other remedy in that affection since he became acquainted with its powers. "A solution," he says in his Dispensatory, "containing between a fortieth and a sixtieth of chloride, applied five or six times a day, or continuously with wet cloths, allays the intense itching in twenty-four hours, and generally accomplishes a cure in eight days." He also recommends it in all eruptions attended with itching.

Administration

For internal use, the dose is from three to six grains, which, in acute cases, may be given every two hours or oftener, in chronic cases three times a day; but, should it irritate the stomach in that dose, as it is said sometimes to do, the quantity must be diminished. The dose should be given in a wineglassful of water, which may be sweetened and aromatized if desired.

For lotions, mouth-washes, and gargles, from one to four drachms of the chloride may be dissolved in a pint of water; and, when the preparation is to be applied to the unbroken skin, in cutaneous eruptions, the solution may sometimes be made of double this strength. When used as a gargle, this solution may be sweetened with honey, and flavoured with aromatics.

An ointment for application to ulcers, or by friction to scrofulous swellings, may be made by incorporating from a scruple to a drachm of the chloride with an ounce of lard or butter.

As an enema, in offensive discharges, from ten to twenty grains may be given, either added to injections for other purposes, or dissolved in half a pint of water.

A solution of Chlorinated Lime (Liquor Calcis Chloratae, Br.) is directed in the British Pharmacopoeia, made by dissolving the chlorinated lime in distilled water, in a fixed proportion, and with certain precautions. The dose is from twenty minims to a fluidrachm. Locally employed, it may be applied of full strength, or diluted with an equal bulk of water, in the former state being used for cutaneous affections.