154 TRANSACTIONS LIVERPOOL BlOLOCxICAL SOCIETY. 



flask. The bulk of water was reduced by beating on the 

 water bath, cooled, and the glycogen again precipitated with 

 alcohol and filtered on to a fresh weighed filter paper. It 

 only remained to give a final washing with ether, and dry the 

 glycogen on the paper at 100° C. The quantity of alcohol 

 used is large, but easily recoverable in a still. The subsequent 

 weighing gave a yield of six grammes of glycogen. The actual 

 amount of time taken during the operation was not great, since 

 the periods required for the sediment and glycogen to settle 

 may be employed in other work. The manner in which the 

 mussel tissue breaks down helps the process considerably, and 

 the haste required in obtaining glycogen for instance from 

 mammalian livers, where inversion takes place immediately 

 after death, is not necessary. 



The only supply of mussels available for many laboratories, 

 however, will be those obtained from local shops, where they 

 may have languished for two or three days. Therefore, in order 

 to effect a comparison with the fresh sample, a second lot of 

 thirty- three mussels were kept until midday of January 29th 

 or 4 days. By this time most of the shells were gaping, and the 

 animals contained had a flaccid appearance although still able 

 to show some little signs of movement. The weight of flesh 

 was less than in the first sample owing to the slow evaporation 

 of the water contents. The same procedure was gone through 

 as in the fresh mussels, and the amount of glycogen obtained 

 was 4-422 grammes, approximately two-thirds of the first 

 amount, but still in sufficient quantities to show that as a 

 cheap and easily-handled source of glycogen, the common 

 mussel is worthy of consideration. 



Estimation of Ash. 



To obtain the non- volatile mineral matter, about 0-5 

 grammes of dried powder was incinerated in a silica crucible. 

 After half an hour of heating to a dull red, the substance was 

 cooled and one or two drops of strong nitric acid added. The 



