GLYCERINUM
   Glycerin, Glycerol. A liquid composed most largely of a trihydric alcohol (C3H5(OH)3) obtained by the processes of hydrolysis and distillation of fats, both animal and vegetable, or of fixed oils. Description.—A thick, syrupy, colorless liquid having a sweet and warming taste and a faint but agreeable odor. It has a great avidity for moisture, becoming appreciably thinner upon long exposure to the atmosphere. It mixes with water or alcohol; and is insoluble in ether, chloroform, and fixed and essential oils. Dose, 1/2 to 2 fluidrachms. Preparation.—Suppositoria Glycerini, Suppositories of Glycerin. Action.—Glycerin is a powerful hygroscopic. So great is its avidity for water that it will readily abstract moisture from the tissues to which it is applied. It is also slightly irritant to the skin and mucous surfaces, and considerably so to abraded surfaces. The discomfort quickly subsides, however, and it then acts as an antiseptic and protective emollient to the skin. It is a demulcent to mucous tissues. Applied to the rectum it provokes evacuation, both by its irritating and dehydrating effects. Glycerin kills parasites, both cutaneous and intestinal, and allays itching, probably by its protective, antiseptic, and hygroscopic powers. Glycerin is rapidly absorbed by the intestines and is mostly oxidized in the body. By some it is thought to be, in some measure at least, a food, and indirectly a conservator of fats through its effects of increasing the non-nitrogenous reserve of the body. It is also believed to increase energy. Upon the glycogenic function its effects are still in doubt, many contending that it reduces the sugar when in excess in the body. Glycerin is laxative and in very large amounts acts not unlike alcohol, producing a similar intoxication and like gastric effects. It is also said to favor the elimination of uric acid. Therapy.—External. The bland and practically unirritating character of pure glycerin, in the presence of a little water, its permanence when exposed to the air (except absorption of moisture), and the completeness with which it shields the parts make it the most largely used external application in a great variety of local disorders. Its protective unctuousness without being greasy, its splendid and extensive solvent powers, its ability to hold in close contact to the tissues powders and other medicines that would dry and fall off if applied with alcohol or water, its antiseptic and emollient properties, and its antipruritic qualities, make it an indispensable vehicle. It is freely miscible with water and most ointment bases, and dissolves or holds in suspension the most commonly used external medicines. It should never be applied full strength, however, except where its dehydrating effects chiefly are desired. Through its great greed for water it readily removes moisture from the tissues, leaving them hardened and more likely to crack. A little water should be added to it for local use, or the parts may be moistened and left wet before its application. Only pure glycerin should be used. Equal parts of glycerin and water, or preferably rose water, form an elegant and emollient cosmetic lotion for chapped hands, lips, and face cracked or sore nipples, excoriated and chafed surfaces, and swollen hemorrhoids. A few grains of borax sometimes add to its efficiency. Compound tincture of benzoin and glycerin is also a pleasant application. For those exposed to winds and storms, and who have their hands much in water, the following is splendidly effective: Rx Glycerin, 2 fluidounces; Carbolic Acid, 10 grains; Tincture of Arnica Flowers, 1/2 fluidounce; Rose Water, enough to make 4 fluidounces. Mix. Sig.: Apply after thoroughly washing and rinsing the hands, and while they are still wet. Sometimes lobelia may be used in place of the arnica. Glycerin, added to poultices, renders them soothing and keeps them moist. It forms a good application to boils, carbuncles, small abscesses, and to local edemas, as of the prepuce. Here it may be used pure for its antiseptic and dehydrating effects. Mixed with alcohol (1 part), glycerin (3 parts), it makes a useful and “drawing” application for boils, and an antiseptic stimulant for foul ulcerations. A mixture of glycerin and water in proportions to suit the case may be used as a toilet wash for the mouth in fevers, to keep the tongue and lips soft and pliable, and to remove sordes and other viscous secretions. It also reduces the thirst occasioned by the dryness of the mouth. Glycerin may be used as a vehicle for lime water for application to small burns, erythema, and slight excoriations; for menthol for the relief of itching in urticaria, chronic eczema, and other pruritic conditions; for boric acid in the mild forms of facial dermatitis; for lactic acid in freckles, sunburn, and other pigmentations; for bismuth, borax, salicylic acid, phenol, boric acid, or sodium or potassium bicarbonate when their long-continued local effects are desired, especially in ulcerations and various skin diseases. A small portion of liquor potassae (1/2 per cent) may be added to it for use upon rough skin and in chronic eczema. Among the skin disorders in which it is especially useful as a vehicle may be mentioned impetigo, lichen, porrigo, psoriasis, pityriasis, herpes, and tinea versicolor (with mercuric chloride) and other parasitic affections. Glycerin (diluted) is one of the best agents to soften hardened and impacted cerumen prior to removing it by gently syringing with warm water. Any irritation caused by the hardened mass or the means of removal may be overcome by the following: Rx Colorless Hydrastis (Lloyd's), 1 fluidrachm; Glycerin, 20 drops; Distillate of Hamamelis, enough to make 1/2 fluidounce. Mix. Sig.: Apply warm to the parts by means of cotton. Glycerin is sometimes useful in otorrhea. A 5 per cent solution of phenol in glycerin upon cotton may be used for insertion into the aural canal after rupture of the membrana tympani wh¹