72 SUGAR OF MILK, GUM, &c. 



in which it is in contact with decaying ghiten, is con- 

 verted into sugar, the starch in the above-named 

 fruits, in a state of decay, or eremacausis, is trans- 

 formed into grape sugar. The more starch the un- 

 ripe fruit contains, the sweeter does it become when 

 ripe. 



A close connection thus exists between sugar and 

 starch. By means of a variety of chemical actions, 

 which exert no other influence on the elements of 

 starch than that of changing the direction of their 

 mutual attraction, we can convert starch into sugar, 

 but it is always grape sugar. 



Sugar of milk in many respects resembles 

 starch ; (13) it is, by itself, incapable of the vinous 

 fermentation, but it acquires the property of resolv- 

 ing itself into alcohol and carbonic acid when it is 

 exposed to heat in contact with a substance in the 

 state of fermentation (such as putrefying cheese 

 in milk). In this case, it is first converted into 

 grape sugar; and it undergoes the same transfor- 

 mation, when it is kept in contact with acids — 

 with sulphuric acid, for example — at the ordinary 

 temperature. 



Gum has the same composition in 100 parts as 

 cane sugar. (14) It is distinguished from the different 

 varieties of sugar by its not possessing the property 

 of being resolved into alcohol and carbonic acid by 

 the process of putrefaction. When placed in con- 

 tact with fermenting substances, it undergoes no 

 appreciable change, whence we may conclude, with 



