. The chemistry of agriculture, for students and farmers. Agricultural chemistry. 56 PLANT COMPOUNDS the same role as dextrose. Levulose is a white solid, crystal- lizable with considerable difficulty, very soluble in water and in hot alcohol. It is much more strongly levorotatory than dextrose is dextrorotatory, the specific rotation being —°. Hence it is called levulose, "left ; It is sweeter than dextrose. Although it does not contain an aldehyde group it is easily oxidized, that is, it reduces Fehling's solution. Levulose forms compounds with calcium hydroxide and bariu
. The chemistry of agriculture, for students and farmers. Agricultural chemistry. 56 PLANT COMPOUNDS the same role as dextrose. Levulose is a white solid, crystal- lizable with considerable difficulty, very soluble in water and in hot alcohol. It is much more strongly levorotatory than dextrose is dextrorotatory, the specific rotation being —°. Hence it is called levulose, "left ; It is sweeter than dextrose. Although it does not contain an aldehyde group it is easily oxidized, that is, it reduces Fehling's solution. Levulose forms compounds with calcium hydroxide and barium hydroxide—''levulates"—insoluble in water and in alcohol. It is fermented by fungi and bacteria like dextrose. One way to make it is to boil sucrose with hydrochloric acid and thereby change the sucrose to dextrose and levulose. On treating the cold solution with an excess of calcium hydroxide, the crystals of calcium levulate are precipitated and can be filtered. On decomposing the precipitate with oxalic acid, and concentrating the filtered solution, levulose will crystallize out. Aside from its use as a food in fruit and honey, where it occurs naturally, levulose has no economic importance. 54. Sucrose, Saccharose, Cane Sugar.—C12H22O11, graphic- allv: H—C—O—H H- -C- 1 -0- -H 1 o H- 1 -C- 1 -0—H H- 1 -c- -0- -H H I H—C—O—H I H—C H—C :-o- -H —0- -H 1. This constitutes a double "sugar" group of atoms or the union of two single groups. Hence it is a disaccharide. It is very widely distributed in plants, being found particularly. Please note that these images are extracted from scanned page images that may have been digitally enhanced for readability - coloration and appearance of these illustrations may not perfectly resemble the original Stoddart, Charles William, 1877-. Philadelphia, New York, Lea & Febiger
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