OF ORGANIC COMPOUNDS. 303 



from sugar, by simply adding the elements of water, 

 or by replacing any one of its elementary constitu- 

 ents by a different substance. The elements neces- 

 sary to form these compounds are, therefore, con- 

 tained in the sugar, and they must also possess the 

 power of forming numerous combinations amongst 

 themselves by their mutual attractions. 



Now, when we examine what changes sugar under- 

 goes when brought into contact with other bodies 

 which exercise a marked influence upon it, we find, 

 that these changes are not confined to any narrow 

 limits, like those of inorganic bodies, but are in fact 

 unlimited. 



The elements of sugar yield to every attraction, 

 and to each in a peculiar manner. In inorganic 

 compounds, an acid acts upon a particular constitu- 

 ent of the body, which it decomposes, by virtue of 

 its aflfinity for that constituent, and never resigns its 

 proper chemical character, in whatever form it may 

 be applied. But when it acts upon sugar, and 

 induces great changes in that compound, it does 

 this not by any superior aflSnity for a base existing 

 in the sugar, but by disturbing the equilibrium in the 

 mutual attraction of the elements of the sugar 

 amongst themselves. Muriatic and sulphuric acids, 

 which differ so much from one another both in char- 

 acters and composition, act in the same manner upon 

 sugar. But the action of both varies according to the 

 state in which they are ; thus they act in one way 

 when dilute, in another when concentrated, and even 

 differences in their temperature cause a change in 

 their action. Thus sulphuric acid of a moderate 

 degree of concentration converts sugar into a black 

 carbonaceous matter, forming at the same time acetic 

 and formic acids. But when the acid is more diluted, 

 the sugar is converted into two brown substances, 

 both of them containing carbon and the elements of 

 water. Again, when sugar is subjected to the action 

 of alkalies, a whole series of different new products 

 is obtained ; while oxidizing agents, such as nitric 



