THE VOLATILE PART OF PLANTS. 75 



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 walnut, 

 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, 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 sugar, 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, &quot; 10 &quot; 



Sorghum 9% Goessmann 



Maize, just flowered, 3% Ludersdorff 



Sugar maple, sap,average 2j^ Liebig 



Red maple, &quot; &quot; 2% &quot; 



&quot;When a solution of this sugar is heated with dilute J 

 acids, or when acted oi\ by yeast, it is converted into a mix- / 

 ture of equal parts of levulose, (fruit sugar,) and glucose, f 

 (grape sugar.) 



The composition of saccharose is the same as that of 

 Arabic acid, and it contains in 100 parts : 

 Carbon 42.11 

 Hydrogen 6.43 

 Oxygen 51.46 



100.00 



Levulose, or Fruit Sugar, (Fructose,) C ia H 34 O 12 , exists 

 mixed with other sugars in sweet fruits, honey, and mo- 

 4 



