102 METAMORPHOSIS OF SACCHARINE MATTER. 
notwithstanding the supply of oxygen was cut off to such an 
extent as almost to occasion death, yet a considerable de- 
struction of sugar took place in the lungs. This, coupled 
with the fact that a disappearance of sugar takes place in 
the systemic capillaries, and unequally so in different por- 
tions of them, induced him to push his investigations, and 
see if there might not be some other cause in operation in the 
living animal to effect the normal destruction of sugar, 
besides the direct chemical action of the oxygen absorbed in 
respiration. The results of these investigations, which were 
first directed towards the changes produced in blood nor- 
mally containing sugar, injected through the capillaries of 
lungs removed from the animal, and artificially inflated with 
atmospheric air or oxygen gas, have induced the author to 
refer the metamorphosis of sugar, in the animal economy, 
to a process w r hich is perfectly consistent and analogous 
with the well-known chemical bearings of this substance 
apart from the animal system. 
In experiments which the author has now several times 
repeated, he injected blood removed from the right side of 
the heart of an animal — and therefore normally containing 
sugar — through the capillaries of the artificially inflated lungs 
of another; and found that as long as the blood retains its 
fibrine, there is as much destruction of its sugar as would 
take place in the living animal; but that where the fibrine 
has been separated from the serum and corpuscles, the 
sugar ceases to be influenced by the presence of oxygen, or 
ceases to disappear during this process of artificial respiration. 
It would hence appear, that something besides mere contact 
w 7 ith oxygen is requisite for the destruction of sugar. But 
in other experiments, he has found that oxygen is neverthe- 
less a necessary agent concerned in the process of transfor- 
mation observed during the arterialization of the blood that 
has not undergone spontaneous coagulation. It would there- 
fore seem, in fact, that oxygen acts secondarily on the sugar 
through the medium of the fibrinous constituent of the 
blood : — that it exerts some changes upon this azotized prin- 
ciple, which are capable of inducing the metamorphosis of 
sugar. 
If we look to the ordinary chemical bearings of saccharine 
matter apart from the animal system, we find that an azo- 
tized substance undergoing the molecular changes of decom- 
position, placed in contact with sugar, readily excites a 
process of fermentation, and converts it by a mere alteration 
of the grouping of its elements into another substance, one 
atom of sugar (C 12 II l2 O l2 ) being resolved into two atoms of 
