CHEMISTRY OF A LUMP OF SUGAR. 95 



The acid is then removed by chemical means, and 

 the solution evaporated to a thick, heavy syrup; 

 for the action of the acid upon the starch has 

 converted it into sugar. Starch sugar and the 

 sweet principle of grapes, when solidified, are re- 

 garded as identical. If we evaporate the starch 

 syrup down to a point of great density, it will, in a 

 few days, solidify into a mass of grape sugar, weigh- 

 ing more than the starch used in its manufacture. 

 These are, indeed, curious transformations ; but 

 still more curious is the fact, that the acid under- 

 goes no change whatever. It is all withdrawn in 

 its original amount after the boiling is completed ; 

 nothing is absorbed from the air, and no other 

 substances but dextrine or grape sugar generated. 

 Our limits do not permit us to explain the nature 

 of these wonderful chemical changes. 



Allusion has been made to the instability of sugar 

 as a chemical compound. The equilibrium of forces 

 in such a body must be very different from that of 

 an inorganic compound. It must be far weaker, and 

 more subject to derangement. The elements are 

 held together by a kind of balance of chemical at- 

 tractions, and remain united only while that balance 

 is exactly maintained. Sugar, even among organ- 

 ized bodies, is peculiarly weak and unstable in con- 

 stitution. A rude diagram, after the following 

 manner, will, perhaps, represent the nature of the 



