LABARRAQUE'S SOLUTION, or LABARRAQUE'S DISINFECTING LIQUID, or SOLU TION or CHLORINATED SODA, a disinfecting liquid first brought into notice by Labarraque, a Paris apothecary. It is prepared by mixing solutions of chlorinated lime, commonly called chloride of lime, and of carbonate of soda (sal soda). Twelve ounces of chloride of lime, 24 of sal soda, and 24 pints of water are the proportions used. The sal soda is dissolved in 3 pints of water, and the chloride of lime is triturated in a mortar with a portion of the water, a little being added from time to time, until the mixture is homo geneous. The remainder of the water is then added to this mixture, which is set aside for 24 hours. The upper portion will be clear; this is to be decanted off, and the residue passed through a muslin strainer until with the decanted portion there are 8 pints. This quantity is then thoroughly mingled with the solution of sal soda, and passed through a muslin strainer, and, if necessary, water added sufficient to make 11i- pints of liquid, which is to be kept in glass-stoppered bottles. Its specific gravity should be 1.045. It has been recommerd d to use bicarbonate of soda instead of common carbonate, or sal soda, because the precipitate of carbonate of lime is rendered thereby more crystalline, and therefore more readily precipitated, rendering the filtration more easy. It is also advised to have the bicarbonate of soda somewhat in excess. Labarraque's solution is a trans parent liquid of a greenish yellow color, having a sharp, bitterish taste and an alkaline reaction. If lime-water be added a precipitate of carbonate of lime will be produced.
It is a powerful disinfectant and bleaching agent, rapidly destroying the color of sulphate of indigo. There has been a good deal of discussion in regard to the precise constitution of this liquid, but it is generally regarded as a mixture of hypochlorite of soda, chloride of sodium, and bicarbonate of soda (using the more common names). According to Millon, the solution contains oxychloride of sodium NaCh0. Its use in medicine is as a gargle in putrid so•e-throat (or diphtheria, q.v.) and in certain cases of scarlet fever, and also as a dressing or wash to gangrenous wounds. In such cases it must be diluted. It is also sprinkledover the floors of sick rooms or hospital wards, or exposed in shallow vessels. It is sometimes administered internally in zymotic diseases, in doses of from 20 to 30 drops, diluted in half a tumbler of water. It is a convenient and agreeable form of chlorine for the housekeeper in bleaching small articles, such as handkerchiefs, which may be readily bleached by adding half a teacupful of the solution to 4 or 5 quarts of water in an earthen wash-bowl, immersing the articles, and exposing them in immersion for a short time to the sunlight or at an open window, stirring from time to time, and afterwards thoroughly and repeatedly rinsing them in clear water.