ORIGIN 01' SUGAR IN THE LIVER. 
293 
period^ but in ordinary conditions, — that is to say, at a long 
time after the last meal, and without attending to the alimen- 
tation of the animal. Our experiments were made on the 
blood of man, the ox, the sheep, and the rabbit. 
The following is one of the processes which enabled us to 
prove very easily the presence of glucose in normal blood. 
At the moment it is drawn from the vein, the blood is 
beaten up, in order to defibrinise it. The quantity to be 
operated on is then weighed, and three times its weight of 
alcohol at 36° is added to it. After a few minutes, the blood 
is completely coagulated into a clot of a beautiful red, by the 
simultaneous precipitation of the globules and of the albumen 
of the serum. It is then strained through a piece of cambric 
muslin and pressed, and the residue is washed with a little 
alcohol. The liquid when filtered passes through almost 
colourless, and manifesting an alkaline reaction. A few drops 
of acetic acid are added to the liquid, so as to communicate 
to it a slight acid reaction, and it is evaporated to dryness on 
a sand-bath. Towards the end of this operation we observe 
the separation of a greenish matter, which is no other than 
the last remains of coagulated albumen. The residue of this 
evaporation, redissolved in distilled water, contains the 
glucose, united with some mineral salts, among which chlo- 
ride of sodium predominates. This liquid powerfully reduces 
Barreswil’s liquor, and furnishes, by boiling, an abundant 
yellow or brick-red precipitate of hydrated suboxide of copper. 
In order accurately to determine the quantity of glucose con- 
tained in the blood operated on, it is sufficient to proceed, 
with Barreswil’s liquor properly filtered, to the determination 
of the exact quantity of sugar which this residue, weighed 
and redissolved in water, contains. 
We succeeded, by means of beer yeast, in extracting 
carbonic acid and alcohol from litres of ox blood collected 
in the slaughter-house. 
As regards the proportion of glucose thus normally con- 
tained in the blood, we found in the blood of a rabbit 0*57 
per cent, of glucose ; the liver of the same animal contained 
1 per cent, of the same product. In ox-blood, 0*48 gr. per 
cent. ; in that of man, 0*38 gr. According to our analyses, 
in equal weight the liver would contain scarcely twice as 
much sugar as the blood contained in other parts of the body. 
It results from the experiments, of which a summary has 
just been given, that we can no longer admit the localization 
of the secretion of sugar in the liver. That which had espe- 
cially contributed to the acceptance of this opinion was 
the fact regarded as indisputable, of the non-existence of 
