Q G. F. Barker—Physiological Chemistry. 
the process being repeated until the glycogen is freed from in- 
organic matter, and particularly from magnesia, of which it at 
first contains a ‘large quantity. Finally, the last precipitate is 
digested in glacial acetic acid to remove the proteic substances 
which it still contains, is well washed, first with alcohol, and 
then with ether, and then dried at 100°C. To compare the 
weight of the elycogen thus obtained with that of the mollusk, 
it is necessary to know how much each of the species mention- 
ed loses in weight by desiccation at 100° C., a datum easily 
obtained. Proceeding as above, Bizio found 14 per cent of 
glycogen in Cardium edule, and 93 per cent in Ostrea edulis, 
while Solen siliqua gave a precipitate too small to be deter- 
min hese numbers acquire significance when it is remem- 
bered that they refer, not to one single organ, but to the whole 
body. He calls attention to the rapidity with which these 
mollusks pass into the lactic fermentation, and states that 
where the glycogen is present in considerable quantity, the 
lactic acid produced suffices to keep the animal from putrefac- 
tion. Hence, from the more or less ready putrefaction of the 
animal, the quantity of glycogen may be inferred. Experi- 
ments show that while the Mytilus edulis and the Cardium 
edule are thus perfectly preserved, the Solen siliqua and Pec- 
ten jacobeeus, which contain less glycogen, readily putrefy. 
Arguing from this analogy up to the tissues of the higher 
animals, Bizio took a piece of human liver, and a piece of ox 
liver, and kept them seven days. The acidity of the former 
as less, = it evolved no odor, while the second gave an ce 
casein is exceeding slow. The principal point which he exam- 
ined, however, was the composition R glycogen. He finds 
that this substance, whether dried at 100° C., or at the ordinary 
*C. R., lrv., 175. 
