C3H5(OH), - 91.79. A triatomic alcohol. Synonym. -Glycerol.

Source

A liquid obtained by the decomposition of vegetable or animal fats or fixed oils (see pp. 13 and 605), and containing not less than 95 per cent. of absolute Glycerin.

Characters

A clear, colorless liquid, of a thick, syrupy consistence, oily to the touch, odorless, very sweet and slightly warm to the taste. When exposed to the air, it slowly abstracts moisture. Sp. gr., not less than 1.250.

Solubility

In all proportions, in Water or Alcohol; also soluble in a mixture of 3 parts of Alcohol and I part of Ether, but insoluble in Ether, Chloroform, Carbon Disulphide, Benzin, Benzol, and fixed or volatile oils.

Glycerin is contained in Elixir Phosphori, Liquor Ferri et Ammonii Ace-tatis, Mucilago Tragacanthae, Massa Hydrargyri, Pilulae Phosphori, in the Glycerita and in many Extracta, Extracta Fluida, Syrupi and Tincturae.

Dose, 5 to 60 m.; .30 to 4.00 c.c

Preparations

1. Glyceritum Amyli. - Glycerite of Starch. Starch, 10; Water, 10; Glycerin, 80.

Dose, freely.

2. Glyceritum Vitelli. - Glycerite of Yolk of Egg. Synonym.- Glyconin. Fresh Yolk of Egg, 45; Glycerin, 55.

Dose, freely.

3. Glyceritum Acidi Carbolici. - See Carbolic Acid, p. 329.

4. Glyceritum Acidi Tannici. - See Tannic Acid, p. 593.

5. Glyceritum Boroglycerini. - See Boric Acid, p. 273.

6. Glyceritum Hydrastis. - See Hydrastis, p. 640.

7. Suppositoria Glycerini. - Suppositories of Glycerin. Glycerin, 60; Sodium Carbonate, 3; Stearic Acid, 5 gm. By solution with heat, pouring into ten moulds, and wrapping in tin-foil, when cold. Each suppository contains 90 gr.; 6. gm. of Glycerin.

Dose, as required.

Action Of Glycerin

External

As glycerin is an excellent solvent for numerous substances, such as iodine, bromine, alkalies, tannic acid, many neutral salts, alkaloids, salicin, etc., it is a good vehicle for applying these substances to the skin and to sores. It does not evaporate nor turn rancid, and is powerfully hygroscopic.

Internal

In man the only visible effect produced by its administration is purging. This occurs with quite small doses if it is given by the rectum, but large doses are necessary if given by the mouth. It is absorbed from the alimentary canal, and is to a slight extent a food, for some of it is oxidized in the body. Sometimes its administration leads to the appearance in the urine of a body which reduces cupric oxide and gives the fermentation test for sugar. There has been much dispute as to whether glycerin can control nitrogenous metabolism, but it appears that it cannot in any way save the waste of nitrogenous tissues. It probably has some influence on the amount of glycogen in the liver. It has also been thought to prevent artificial glycosuria, but this is doubtful.

Very large doses in animals cause the urine to be dark from the presence of the coloring matter of the blood, although there are no corpuscles in it; they also lead to loss of muscular strength, lethargy, dryness of mucous membranes, collapse and death.

Therapeutics Of Glycerin

External

Glycerin is much employed as a basis for applications to the skin and the eye. It is commonly used for chapped hands and slight excoriations. It is readily absorbed when rubbed into the skin, therefore it is a convenient vehicle for the absorption of substances by the skin. Belladonna mixed with glycerin is often rubbed in when we desire its local anodyne action (see p. 379.) Glycerin as well as boroglycerin (see p. 273) is used extensively in various local applications in the treatment of diseases of women.

Internal

As glycerin is sweet, it is an excellent flavoring agent. It is demulcent, and is used as a vehicle for applying substances, such as tannic acid, to the throat. It is rarely given by the mouth for any medicinal virtue. It has been administered for dyspepsia, for diabetes, and as a nutritive agent, but in each case without any good result. One to two fl. dr., 4. to 8. c.c injected into the rectum, or a glycerin suppository, form an excellent means of opening the bowels in simple constipation, especially when the faeces are in the sigmoid flexure and rectum. The result is prompt, often occurring within less than half an hour. No pain nor constitutional disturbance is produced.