THE CHEMISTRY OF THE SUGARS 85 



The first alcohol which fulfils the definition given above 

 CH2OH 

 is glycol, | , so named from its sweet taste, and 



CH2OH 



CH2OH 

 the corresponding sugar is glycol-aldehyde, | 



CHO 

 The next member of the series of alcohols is glycerol or 

 ordinary glycerine, whose sweet taste is a matter of common 



CH3OH 



knowledge. The formula for glycerol is CHOH, from which 



CH3OH 



it is evident that two first products of oxidation can be 

 obtained, that is, the CHjOH group may oxidise to an aldehyde 



group — C or the CHOH to "^CO, the characteristic 



ketonic group, and thus we have the following relationship : — 



CH2OH 



I 

 CHOH 



1 

 CH2OH 



Glycerol 



These last two substances are the first representatives of 

 two important groups of the mono-saccharoses, viz., the 

 aldoses and the kctoses, the former containing the aldehyde 



/H 

 group — C and the latter the ketonic group ^C=0. 



"^0 

 The sugars it will be noted end in ose, and according to the 

 number of carbon atoms they are referred to as biose, triose. 



