66 HOW CROPS GAOW. 



elements of water and are thereby resolved into glucoses. 

 In this decomposition one molecule of sucrose usually 

 yields either two molecules of one glucose or a molecule each 

 of two glucoses, C 12 H 22 U -f ILO = C 6 H 12 6 -f C 6 H 12 6 . 



Saccharose, or Cane Sugar, Ci 2 H 22 On, so called 

 because first and chiefly prepared from the 

 sugar-cane, is the ordinary sugar of com- 

 merce. When pure, it is a white solid, 

 readily soluble in water, forming a color- Fig. 14. 

 less, ropy, and intensely sweet solution. It crystallizes 

 in rhombic prisms (Fig. 14), which are usually small, as 

 in granulated sugar, but in the form of rock-candy may 

 be found an inch or more in length. The crystallized 

 sugar obtained largely from the sugar-beet, in Europe, 

 and that furnished in the United States by the sugar- 

 maple and sorghum, when pure, are identical with cane- 

 sugar. 



Saccharose also exists in the vernal juices of the wal- 

 nut, birch, and other trees. It occurs in the stems of 

 unripe maize, in the nectar of flowers, in fresh honey, in 

 parsnips, turnips, carrots, parsley, sweet potatoes, in the 

 stems and roots of grasses, in the seeds of the pea and 

 bean, and in a multitude of fruits. 



EXP. 29. Heat cautiously a spoonful of white sugar until it melts (at 

 356 F.) to a clear yellow liquid. On rapid cooling, it gives a transpar- 

 ent mass, known as barley swjar, which is employed in confectionery. 

 At a higher heat it turns brown, froths, emits pungent vapors, and be- 

 comes burnt sugar, or caramel, which is used for coloring soups, ale, etc. 



The quantity per cent of saccharose in the juice of various plants is 

 given in the annexed table. It is, of course, variable, depending upon 

 the variety of plant in case of cane, beet, and sorghum, as well as upon 

 the stage of growth. 



SACCHAROSE IN PLANTS. 



Per cent. 



Sugar-cane, average 18 Peligot. 



Sugar-beet, " 10 " 



Sorghum 13 Collier. 



Maize, just flowered 3| Liidersdorff. 



Sugar-maple, sap, average 2i Liebig. 



Bed maple, " " 2J " 



