A sweet principle obtained from fats and fixed oils, and containing 5 per cent. of water.

Characters.-A clear colourless fluid, oily to the touch, without odour, of a sweet taste, a free solvent of many substances. Sp. gr., 1.250. Dose, 1 to 2 fl.dr.

Preparations.

1. Glycerinum Acidi Carbolici

Glycerinum Acidi Carbolici. 4 to 1.

2. Glycerinum Acidi Gallici

Glycerinum Acidi Gallici. 4 to 1.

3. Glycerinum Acidi Tannici

Glycerinum Acidi Tannici. 4 to 1.

4. Glycerinum Amyli

Glycerinum Amyli. 8 to 1; heated to 240° Fahr., until a jelly is formed. 5. Glycerinum Boracis,-4 to 1.

Glycerine is also a constituent of:

Linimentum Potassii Iodidi cum Sapone.

Action And Uses. 1. Immediate Local Action And Uses

Externally.-Glycerine is a slightly stimulant, antiseptic, hygroscopic, and adhesive substance, which forms a useful application to skin diseases and small sores, such as chaps, whether alone or in combination with other remedies as a lotion, instead of ointments, which become rancid. (In the pure state it is used to preserve microscopic specimens and vaccine lymph.) Glycerinum Amyli is used as a basis for ointments.

Glycerine is readily absorbed by the unbroken skin, and will carry in with it certain active substances, such as extract of belladonna. Glycerates may thus produce specific effects. It is also applied to the cervix uteri, conjunctiva, meatus auditorius, and other exposed mucous surfaces.

Internally.-Glycerine is very sweet, and imparts a smooth sweet agreeable taste to nauseous or astringent mixtures, rendering the addition of sugar unnecessary. As a topical stimulant and demulcent, it is an excellent vehicle for such applications for sore throat as tannic acid. In the stomach it produces no special effect; but is a mild laxative when freely given. As an enema, it has been administered in ulceration of the bowels.

2. Action On The Blood

Glycerine is freely absorbed by all surfaces, and is one of the normal products of the digestion of oils and fats in the intestines. In large quantity it is said to cause the solution of the red corpuscles, the diffusion of the haemoglobin in the plasma, and consequent haemoglobinuria.

3. Specific Action And Uses

Glycerine has been supposed to be nutritive, and may contribute to the formation of adipose tissue, as a portion of the fats and oils of food must be decomposed in digestion, and the glycerine again united with the fatty acid in the process of nutrition. The results obtained from the administration of glycerine instead of oils in phthisis have been very divergent, and on the whole not encouraging. The same may be said of its use in diabetes.

4. Remote Local Action And Uses

Glycerine is decomposed in the system, and passes out as propionic, formic, and other acids. The urine of persons taking glycerine contains a reducing body which gives the copper and fermentation-tests of sugar, but is not sugar. Haemoglobinuria after large doses has been already referred to.