They possess a delicate Laticiferous layer of protoplasm, with numerous small nuclei lining Tissue the walls, while the interior of the tube (corresponding with the cell-vacuole) contains a fluid called latex, consisting of an emulsion of fine granules and drops of very various substances suspended in a watery medium in which various other substances (salts, sugars, rubber-producers, tannins, alkaloids and various enzymes) are dissolved.
Cane sugar has been known for many centuries; milk sugar was obtained by Fabrizio Bartoletti in 1615; and in the middle of the 18th century Marggraf found that the sugars yielded by the beet, carrot and other roots were identical with cane sugar.
It is convenient to divide the sugars into two main groups: monosaccharoses (formerly glucoses) and disaccharoses (formerly saccharoses).
The first term includes simple sugars containing two to nine atoms of carbon, which are known severally as bioses, trioses, tetroses, pentoses, hexoses, &c.; whilst those of the second group have the formula C12H22011 and are characterized by yielding two monosaccharose molecules on hydrolysis.
All sugars are colourless solids or syrups, which char on strong heating; they are soluble in water, forming sweet solutions but difficultly soluble in alcohol.