CONSTITUTION OF THE SUGAR SERIES. 165 



H 



I 

 f C— H 



which becomes the first member of the series and this may be 

 called Monose. Acetic acid being the second in the series of fatty 

 acids becomes the second of the new group — Biose 



H 



I 

 H— C— H 



f C— HO 



The oxidation of glycerol and subsequent treatment with phenyl- 

 hydrazine by Fischer and Tafel gives us the third member, namely 

 — Triose. 



H HO 

 \0/ 



HO— C C— H 



/ \ 



H HO 



and triose may be regarded as the earliest one of the series pos- 

 sessing sugar-like properties. 



Next is Tetrose, the only one yet prepared being Erythrose 



HO H 



I I 

 H— C C— HO 



HO— C C— H 



I I 



H HO 



Pentose follows with three well-known examples : these being 



Arabinose (present in many New South Wales plants), Xylose 



and Rhamnose. 



By far the most important yet known is the sixth group — 

 termed Hexose which includes many sugars known from the 

 earliest period of the world's history, and for which I propose a 

 ring somewhat similar to the Benzene chain, but with different 

 linkage, thus instead of alternate double linkage there is but a 

 single linkage throughout. 



