39. Saccharum.—Sugar.
Cane-sugar.
The refined sugar obtained from Sac'charum officina'rum Linné, and from various species or varieties of Sorghum, also from one or more varieties of Be'ta vulga'ris Linné (nat. ord. Chenopodiaceae).
SOURCE AND VARIETIES.—The sugar cane is extensively cultivated in Africa, East and West Indies (especially Cuba), Brazil, and Southern United States, particularly Louisiana. The sugar beet is extensively cultivated in France and Spain, and has been introduced with varying success into some parts of the United States. Cane-sugar is also a constituent of the sugar maple; of the carrot and turnip, of cassia pulp, etc. The sugar in fresh fruit is mainly cane-sugar; by the action of the fruit acids, or a ferment, it is generally inverted, becomes uncrys-talline, and influences polarized light in the opposite direction from that of cane-sugar, twisting the ray from right to left. Honey-sugar is probably a mixture of the two varieties—right- and left-handed. It is readily altered to a crystalline and granular mass of grape-sugar in dried fruit, as in the raisin, the prune, and solidified honey. This, the common form of grapesugar, is right-handed, and is called dextrose (dextrogyrate), to distinguish it from laevulose. Barley-sugar is made by heating canesugar till it fuses, becoming thus, in a great measure, uncrystalline. Molasses (treacle)—Syrupus fuscus (official 1860-1870)—is the result from the evaporation of cane-sugar syrup; it is a mixture of canesugar with uncrystallizable sugar and coloring matter.
DESCRIPTION.—Sugar or sucrose, C12H21O11, is in "white, dry, hard, distinctly crystalline granules, odorless, and having a purely sweet taste. Permanent in the air." The aqueous solution saturated at 15°C (59°F.) has a sp. gr. of 1.345 and is miscible with water in all proportions, soluble in 175 parts of alcohol.
OTHER SUGARS. Saccharum Lactis.—Lactose obtained from the whey of cows' milk and purified by recrystallization.
SOURCE AND DESCRIPTION.—It is prepared from cows' milk by evaporating the whey after removing the curd. Cows' milk contains from 4-5 to 4.9 per cent. of sugar. It crystallizes in large hard prisms, has a feebly sweet taste and is soluble in six parts of cold water. It occurs in white, hard crystalline masses or as a white powder feeling gritty to the tongue, odorless, permanent in air. Like cane-sugar it forms compounds with metallic oxides, and reduces alkaline copper solutions. Practically insoluble in alcohol, ether, or chloroform. It is not effected directly by ferments. When heated with mineral acids it forms dextrose and galactose.
ACTION AND USES.—When injected into the blood-vessels it appears unaltered in the urine. When taken in the alimentary canal it is perfectly assimilated. When administered in large doses it acts as an active diuretic. Milk loses this diuretic effect on being boiled. Used in making tablet triturates.
MANNOSE (from mannite); maltose (from starch by the action of dilute acid or diastase); melitose (from eucalyptus).
CARAMEL, N.F. is a name applied to burnt sugar (Saccharum ustum), used in the liquid form as a coloring for spirits, vinegar, etc.
SACCHARUM UVEUM.—Grape-sugar. Glucose. Yellowish or whitish masses or granules much less sweet than cane-sugar. Composition C6H12O6H2O
ACTION AND USES.—Demulcent and lenitive. Used in making the various syrups and compound syrups of the Pharmacopoeia, etc.
OFFICIAL PREPARATION.—Syrupus.
