26 
STARCH FROM THE ANIMAL KINGDOM. 
impregnated with sugar, the production of this material 
having continued in the exsanguine tissue of the gland. 
Upon this fact our knowledge had rested until within the 
last few months. During the early part of the summer. 
Dr. Pavy had noticed, whilst conducting his experiments on 
the destruction of sugar (which have led him to new and unex- 
pected results which he will shortly communicate to the pro- 
fession), that he could isolate a material from the liver which 
subsequently underwent transformation into sugar; and he 
had recorded in his laboratory-book the influence of chemical 
agents, such as acids, alkalies, and alcohol, on this material. 
He had since learnt, however, on his recent visit to Paris, 
that Bernard had most satisfactorily made out the nature 
and relations of this body, w’hich, from the analogy presented 
in its chemical bearings to starch, he had called an animal 
amylaceous or starchy material. It had also been called 
glucogenic material, and this w as probably the best term to 
apply to it at present, because it implied nothing more than 
w e knew the substance in reality to be. The specimen of 
this glucogenic material which Dr. Pavy exhibited had been 
procured from the liver of a dog in the following manner: — 
The dog had for some days been submitted to a strictly 
animal diet, so as to preclude the introduction of any starchy 
material into its system from the vegetable kingdom. After 
killing the animal, by the destruction of the medulla oblon- 
gata, the liver w'as removed, and a tube firmly ligatured in 
the pnrtal vein, for the purpose of passing a current of water 
through the vessels to w^ash out, the blood, and at the same 
time remove the sugar. In half an hour’s time the water 
which had passed through the vessels was colourless and 
destitute of sugar, as w 7 as also the tissue of the liver itself. 
The organ w 7 as now 7 cut up into small slices, placed in an 
evaporating dish, boiled in the liquid w 7 hich exuded from it, 
and subsequently strained and pressed to obtain all the 
jiiquid that was procurable. The object, in fact, was to make 
decoction of the liver, which holds in solution the gluco- 
igt^ic material, and has, thereby, communicated to it an 
opalescent or a milky appearance. This w 7 as then mixed 
with alcohol (in the proportion of one part of the decoction 
to about five of the spirit), and immediately a precipitate was 
produced, which w T as collected on a filter and dried, and 
formed the specimen then before the Fellow s of the Society. 
The substance before him was of a greyish colour, which 
resulted from contamination w r ith albuminous matter. It 
might be made perfectly w T hite by prolonged boiling in a 
solution of potash, which did not at all affect its properties. 
