359 
C—OH C—O# 
d-xylose which had to show the same was partially retained. 
The experiments have thus yielded two results: 
1. Of all the investigated sugars (hexoses and pen- 
toses) glucose alone is retained completely. 
2. This exceptional property of glucose cannot be 
C—OH 
ascribed to the group of atoms H—C—OH and just 
as little to a larger group of atoms in the molecule. Lt 
seems to be inherent in the whole atomic grouping of 
the glucose molecule. 
Still it will appear in the following article, in the light of partial 
retention, of how much importance the group H—C—OH_ is here. 
The experiments described above were partly made by Mr. C. L. 
Arons, Med. Cand. assistant in the laboratory. 
Groningen, September 1919. Physiological laboratory. 
