how far it leads to an economy of the nitrogenous tissues, as the fats and carbohydrates do. Internally, as well as externally, glycerin is a good demulcent, but, since it is so quickly absorbed, its action does not extend beyond the stomach. In some forms of experimental glycosuria glycerin appears to reduce the amount of sugar present, and it is believed that it probably has some effect on the sugar formation in the tissues, although no satisfactory explanation of its action in this particular has as yet been given. It has a decided value as an antiseptic, and this is probably due to its hygroscopic properties. It is destructive to parasites, both intestinal and external. THERAPEUTICS OF GLYCERIN External. Glycerin is employed to a greater extent externally than as an internal remedy. It is an extremely useful emollient, and as it does not evaporate or turn rancid, and is readily absorbed when rubbed into the skin, it has many advantages as a vehicle for the application of active medicinal agents. Glycerin, diluted one-half with distilled water, is of great service in relieving the dryness of the lips, mouth and tongue in fevers. A mixture of glycerin, crystallized sugar, and whiskey, which is allowed to trickle down the throat, may also be given for the same purpose. Among the many other useful applications of glycerin are the following: For chapped face and hands, sore nipples, and piles it may be combined with rose water; for excoriations, erythema, and superficial burns, with lime water; for erythematous or vesicular eczema, burns, and seborrhoea, especially about the axilla and the genital organs, with phenol and either bismuth subnitrate or sodium bicarbonate; for freckles and other skin pigmentations with lactic acid, and for pruritus, eczema and urticaria with menthol. The latter combination with eucalyptol, may also be used, in the form of a spray, in nasal catarrh, pharyngitis and laryngitis. The glycerite of tannin makes an excellent astringent application for chronic follicular pharyngitis, relaxed mucous membranes, and other conditions. The glycerite of starch is frequently employed as a vehicle for the application of astringents to the eye, and glycerin and its preparations are also much used in ear affections. Glycerin is a convenient vehicle for promoting the absorption of various drugs by the skin. Glycerin, either alone or combined with an astringent or sedative, may be employed for the prevention of bed-sores. Glycerin, as well as boroglycerin (see p. 321), is used extensively in various local applications in the treatment of diseases of women, and in congested states of the genital organs it is of special service by causing, on account of its affinity with water, an abundant serous transudation. Internal. On account of its sweetness glycerin is employed to a considerable extent as a flavoring agent. Large doses sometimes. cause purgation, but it is not a reliable remedy for this purpose, and alone is seldom given by the mouth as a laxative, except perhaps for hæmorrhoids, upon which it is asserted to have a peculiarly soothing effect. To produce efficient cathartic action it is necessary that it should be combined with magnesium sulphate or carbonate, and tincture of rhubarb and of belladonna. As a laxative, however, it is much more frequently administered by the rectum, where 8 mils (2 fl. dr.) produces a prompt evacuation, without pain or other disturbance; the most convenient way to use it is in the form of a suppository. The glycerin is said to pass upwards. as far as the sigmoid flexure, and even beyond. While from contact it may perhaps increase the peristalsis of the large intestine, the local irritation of the anal canal is itself no doubt sufficient to set up reflex movement of the bowel. Glycerin has been advised by some as a food in conditions of malnutrition, but, it is an inferior substitute for cod liver oil and other fatty substances. It was formerly used to a considerable extent by diabetics as a substitute. for sugar as a sweetening agent but its sweetness is of a rather disagreeable kind and its place has now largely been taken by saccharin. Glycerin, it has been found, is capable of destroying trichinæ in the intestinal tract, and it is therefore a remedy of distinct value in patients suffering from trichiniasis. Among other conditions in which it has been used internally may be mentioned vomiting of pregnancy, gallstone disease, and nephrolithiasis. CHONDRUS For the Preparations of Chondrus see p. 225. ACTION AND THERAPEUTICS OF CHONDRUS Chondrus is demulcent and somewhat nutrient, though the gum which enters largely into its composition is not readily digestible. The decoction, which is not official, was formerly much used in bronchial affections, diarrhoea, dysentery and irritation or inflammation of the genito-urinary tract. Whatever beneficial effect it may have had was probably due to its protective qualities, and also possibly, to some extent, to the influence on nutrition of the minute quantity of iodine in it. When made into a jelly it is a pleasant article of diet, but it is really of not marked nutritive value. AGAR For the Preparations of Agar see p. 225. ACTION OF AGAR Agar is a demulcent, which can absorb water and soften to a jellylike mass. It is not absorbed from the alimentary tract and for that reason should not be considered to be a food. THERAPEUTICS OF AGAR It has enjoyed an extensive reputation as a remedy for constipation on account of its softening the fæces and increasing the amount of contents of the intestine. It may be administered in small fragments and given with stewed apples or mashed potatoes or by cooking it in water until it forms a thin jelly which, however, is very difficult of administration an account of its adhesive properties. On account of its being itself readily decomposed and of its being a good culture medium, mechanically retarding absorption in the intestine and from its demulcent properties, lessening irritation in the intestine, although its bulk will prevent diminished peristalsis, it has been the rule to administer with it some remedy of acknowledged purgative properties as cascara sagrada. Administered in this way it is efficient in overcoming intestinal stasis and diminishing autointoxication. ALTHEA For the Preparations of Althæa see p. 227. ACTION AND THERAPEUTICS OF ALTHÆA Althea is demulcent, emollient and slightly nutritious. It is a useful demulcent for irritation of mucous membranes, espe cially as a remedy for pharyngitis. An excellent emollient poultice is made from the powdered root, and, combined with benzoinated lard, it is employed as a bland dressing in cutaneous affections. It is a constituent of blue mass and used in pills of ferrous carbonate and of phosphorus, to which it serves to give the proper consistence. GELATIN For the Preparations of Gelatin see p. 250. ACTION AND THERAPEUTICS OF GELATIN Gelatin is a demulcent and styptic, and is also believed to be, to a considerable extent, nutrient, in the same direction, though not in the same degree, as albumin. It is used as a basis for capsules, lozenges, and suppositories, as a coating for pills, and as a protective covering in certain diseases of the skin. Although it is a proteid which can be used as a food, indol cannot be formed from it and for that reason it can be employed in that form of intestinal putrefaction in which indicanuria is marked. Sterilized gelatin in a 1 per cent. solution has been administered by hypodermatoclysis or intravenously, to the amount of 100 mils (3 fl. oz.) to increase the coagulability of the blood in hæmorrhage or aneurism. As an antidote, gelatin is of especial value against poisoning by iodine, bromine and the alums, but requires much time for its preparation, since for this purpose it should be broken up and reduced to the consistency of honey by being soaked for half an hour in water. STARCH For the Preparations of Starch see p. 233. ACTION AND THERAPEUTICS OF STARCH Starch is demulcent and nutritive, and an important member of the non-nitrogenous group of alimentary principles known as carbohydrates, which are mainly concerned in heat-production. The excessive consumption of starchy food delays tissue-metamorphosis, causes a redundancy of fat, and often gives rise to acidity and flatu lence. Undigested starch passes into the fæces, and the urine may become saccharine. Medicinally starch is inert, and it is used principally on account of its mechanical properties, which make it a good basis for dusting powders and insufflations, and to keep pills from adhering to each other. The glycerite is emollient, and is also employed as a basis for suppositories. Injections of starch water are soothing in irritative conditions of the lower bowel. The starch must be hydrolyzed by boiling about 4 gm. (1 dr.) with 60 mils (2 fl. oz.) of water, until it forms a clear paste and then diluting it with water to 500 mils (1 pt.). Starch is employed as an antidote in poisoning by iodine or bromine. SUGAR OF MILK For the Preparations of Sugar of Milk see p. 250. ACTION AND THERAPEUTICS Of Sugar of MILK Being very hard, and also but slightly deliquescent, it is a valuable excipient for powders requiring the minute subdivision of their medicinal constituent and as a diluent to bring extracts to the required strength. It has been used as a carbohydrate food in phthisis and other wasting diseases, and, on account of its lesser liability to ferment, is preferred to cane-sugar for infant's food. It is also a serviceable food in acute febrile diseases, especially typhoid fever, and, being tasteless and easily soluble it may often be taken with advantage to the extent to 60 gm. (2 oz.) or more each day. It is a diuretic which may be employed in cardiac dropsy; but its action is slight when extensive renal disease exists. DIVISION V.-DRUGS ACTING ON THE SKIN While the drugs described in the preceding Division act on the cutaneous blood-vessels, in addition we have A. Diaphoretics, drugs which increase the amount of perspiration. These may do this: (1) By affecting the circulation in the skin. This may be locally (by local irritation) or systemically. In the latter, the action may be an indirect one, and due to a rise of |