101 
METAMORPHOSIS OP SACCHARINE MATTER. 
If the blood of an animal normally impregnated with sugar 
be placed aside, and allowed to undergo spontaneous coagu- 
lation, on examining separately the serum and clot on the 
following day it will be found, that although the serum may 
be largely saturated with sugar, the clot is entirely, or almost 
entirely, destitute of it. Now, as the clot is moist and 
remains to a certain extent infiltrated with the serum from 
which it has partially separated, it would appear that even 
the molecular changes arising from the spontaneous coagula- 
tion of the blood are sufficient to effect the destruction of 
normal animal sugar ; and this conclusion is strengthened by 
the fact, that in diabetic blood (the sugar of which, as would 
appear from other considerations also, is not so susceptible of 
metamorphosis as the healthy variety) the sugar does not dis- 
appear to a similar extent in the clot. 
Under the changes of the decomposition of blood, normal 
animal glucose is very readily metamorphosed. The rapidity 
of the metamorphosis depends on the activity of the decom- 
position of the animal substances present, and when the 
destruction of the sugar is complete the blood has assumed 
an acid reaction. 
This acid reaction of decomposing blood is only observable 
in that which w as previously pretty largely impregnated w ith 
sugar. It appears to be owing to the formation of lactic 
acid. Certainly, it cannot be due to carbonic acid, for the 
reaction remains after exposure to a boiling temperature. 
The disappearance of sugar in the manner just pointed 
out does not depend on the oxygen of the air, except in so 
far as this agent is concerned in exciting the decomposition 
of the azotized constituents of the blood; for the sugar dis- 
appears as rapidly when there is a small, as when there is a 
large amount of surface exposed to the air. But if the air be 
carefully and completely excluded, no signs of decomposition 
of the animal parts of the blood are to be observed, and under 
these circumstances the sugar also remains. The disappear- 
ance of sugar is more rapid where the fibrine and corpuscles 
are present, than when the serum is exposed alone ; and in 
accordance with this, the blood in the one case undergoes 
decomposition much sooner than in the other — a fact easily 
intelligible from the greater amount of azotized ingredients 
present. 
If blood normally impregnated with saccharine matter be 
placed aside until signs of incipient decomposition are 
observed, and the sugar is beginning to disappear, exposure 
to a current of oxygen rapidly completes the total disappear- 
ance of the saccharine constituents. In this observation we 
