720 GRAMINE^. 



pounds some of which are crystaUizable, From an alkaline solution of 

 tartrate of copper, cane sugar throws down no protoxide, unless after 

 boiling. 



If sugar is kept a short time in a state of fusion at 160° C, it is 

 converted into one molecule of Grape Sugar and one of Levulosan; 

 the former can be either isolated by crystallization or destroyed by fer- 

 mentation, the latter being incapable of crystallizing or of undergoing 

 fermentation. 



Cane sugar which has been melted at 160° C. is deliquescent and 

 readily soluble in anhydrous alcohol, and its rotatory power is diminished 

 or entirely destroyed. It is no longer crystaUizable, and its fusing point 

 has become reduced to about 93° C. Yet before undergoing these 

 evident alterations, it assumes an amorphous condition if allowed to 

 melt with a third of its weight of water, becoming always a little 

 coloured by pyrogenous products. In the course of time, however, this 

 amorphous sugar loses its transparency and reassumes the crystalline 

 form. Like sulphur and arsenious acid, it is capable of existing either 

 in a crystallized or an amorphous state. 



If sugar is heated to about 190° C. water is evolved, and we obtain 

 the dark brown products commonly called Caramel or Burnt Sugar. 

 They are of a peculiar sharp flavour, of a bitter taste, incapable of fer- 

 menting and deliquescent. One of the constituents of caramel, Cara- 

 mielaiie, (J-W^O'\ has been obtained by Gelis (1862) perfectly colourless. 

 When the heat is augmented, the sugar at last suffers a decomposition 

 resembling that which produces tar (see p. 621), its pyrogenous products 

 being the same or very analogous to those of the dry distillation of wood. 



Varieties of Cane Sugar — The experiments of Marggraf referred 

 to at p. 717, note 9, showed that cane sugar is by no means confined to 

 the sugar cane ; and it is in fact extracted on an extensive scale from 

 several other plants, of which the following deserve mention : — 



Beet Root — The manufacture of cane sugar from the fleshy root of 

 a cultivated variety of Beta maritima L., is now largely carried on in 

 Continental Europe and in America, and with admirable results. 



Of fresh beet root, 100 parts contain on an average 80 per cent, of 

 water, 11 to 13 of cane sugar, and about 7 per cent, of pectic and albu- 

 minous matters, cellulose and salts. Of the total amount of juice which 

 the root contains, eight-ninths are extracted ; and by the best process 

 now in practice, 8 to 9 parts of sugar from every 100 parts of fresh root. 

 The yield of crystalline sugar is still on the increase, owing to continual 

 improvements in the mechanical and chemical parts of the process. 



Palm — Several species are of great utility for the production of the 

 sugar called by Europeans Jaggery^ This substance is obtained by the 

 natives of India in the following manner : — The young growing spadix, 

 or flowering shoot, of the palm is cut off near its apex ; and an earthen 

 vessel is tied on to the stump to receive the juice that flows out. This 

 vessel is emptied daily ; while to promote a continuous flow of sap, a 

 thin slice is cut from the wounded end. The juice thus collected, if at 

 once boiled down, yields the crude brown sugar known as jaggery. If 

 allowed to ferment, it becomes the inebriating drink called Toddy or 



* A word of Sanskrit origin, corrupted from the Canarese sharkari. 



