KR. H. Chittenden— Dehydration of Glucose. 259 
tion of saccharose was noticed when the sugar solution was warmed 
for two hours with a portion of stomach tissue from a rabbit killed 
in full digestion. The reduction with Fehling’s solution was quite 
strong. 
With glucose, however, many experiments have been tried in addi- 
‘tion to those given above, and invariably with the same negative 
result. The conditions of the experiments, moreover, are in many 
cases identical with those of Pavy’s except in the method of deter- 
mining reducing power. There seems, therefore, to be no plausible 
explanation of the results obtained, other than that in the above 
experiments there was no dehydrating ferment present. Pavy states 
that the ferment in question, or rather ‘‘the active principle con- 
cerned in the transformation of glucose is susceptible of being de- 
stroyed by the agency of gastric digestion,” so that there is the pos- 
sibility of such destructive action having taken place in the stomach 
of the animals experimented with. It is further stated, however, 
that the converting principle is situated in the underlying portion of 
the mucous membrane, so that destruction could hardly be expected, 
except perhaps in the slow self-digestion occurring after death. Cer- 
tainly, the carefully rinsed tissue could not have retained sufficient 
gastric juice to affect the results. Furthermore, such decomposition 
would apply only to the stomach mixture and not to the intestines, 
unless sufficient proteolytic ferment from the pancreatic juice should 
adhere to the walls of the intestines to exert destructive action; but 
in the last experiment given, it is to be noticed that the saccharose 
ferment, which is presumably equally sensitive, showed vigorous 
action while the glucose was unaffected. 
It seems strange, therefore, if such a dehydrating ferment is norm- 
ally present in the alimentary tract, that we have not been able to 
obtain some tangible evidence of its presence, either in the stomach 
or intestines. 
Since the above was written, the writer has noticed that M. 
Ogita,* experimenting with dogs, has also been unable to confirm 
Pavy’s results, both in the dehydration of glucose and in the inver- 
sion of saccharose. 
*See Jahresbericht fiir Thierchemie, xv, 275. 
