242 



THE INCOME OF ENERGY 



sugar) are the first oxidation products of the hexahy- 

 dric alcohols ; the higher carbohydrates are anhydrides 

 of the monosaccharides. Most of the higher carbohy- 

 drates cannot be fermented directly, but must first 

 be hydrolyzed (i. e. take up water). This hydrolysis 

 may be accomplished by the prolonged action of dilute 

 acids at high temperatures, by the action of water at 

 still higher temperatures, or by specific ferments,' e. g. 

 diastase, at the relatively low temperature of the body. 

 The polysaccharides, consisting of the starches, the 

 gums (e.g. dextrine or starch gum) and the celluloses 

 (wood fibre) differ greatly from the lower carbohy- 

 drates. The poly sacchar idea are usually amorphous 

 and are not easily soluble in water. 



CARBOHYDRATES. 1 



1 Richter's Organic Chemistry, Third American Edition, i, 

 p. 121. 



