CHEMICAL CHANGES OCCURRING IN OYSTERS. 21 
per cent; amino nitrogen, 59.1 per cent; ash, 52.3 per cent. Thus in 
this experiment the actual loss of total solids is only 5.3 per cent of 
the original amount present, probably soluble ammo compounds and 
inorganic salts, while the actual loss of amino acids is 19.2 per cent 
and that of ash-forming substances is even greater, amounting to 26 
per cent. As the osmotic loss is in each case 21.7 per cent, it is 
clear that the actual loss of total solids is relatively slight compared 
to it, while the actual loss of amino acids and other soluble constitu¬ 
ents is as great as, or greater than, the osmotic loss. These figures 
do not represent commercial practice, however, for, in general, oysters 
are washed for about 30 minutes. 
Experiment J +.—In this experiment the increase in volume and, 
therefore, the osmotic loss are zero. The actual loss of amino acids 
is also zero, and that of total solids is only 5.6 per cent. The actual 
loss of ash is rather high but is far lower than when the washing is 
done by the other method. 
Experiment 5 .—The results of this experiment show a gain in 
volume of 25 per cent. This makes the percentage figure for each 
substance 80 per cent and the osmotic loss 20 per cent. As the 
derivation of these figures already has been given in detail (Table 
7), it will not be enumerated for this and the following experiments. 
Experiment 7 .—The maximum osmosis was observed at the end of 
30 minutes of washing in this method. The maximum osmotic 
increase was 22.1 per cent, about 5 per cent less than that observed 
in the case of air agitation. As will be shown later, this lower 
value is due solely to the excessive handling inherent in this method 
of repeated measurement and not to any difference in the methods 
of agitation. The percentage of losses will be seen to correspond 
rather closely to those observed in the air-agitation experiments. 
It is interesting to note, however, that at the end of 40 minutes the 
loss of total solids stopped, probably because of shrinkage in volume 
caused by the excessive handling already mentioned. The per¬ 
centage of amino acids, however, continued to fall. The ash was 
apparently reduced to a minimum, the remainder being practically 
all insoluble. The percentages in Table 7 are calculated from the 
results at the end of 30 minutes, so that they closely represent com¬ 
mercial practice. 
Experiment 8 .—In the calculated results of this experiment the 
30-minute results are used, as these are representative of commercial 
practice. It will be observed that these results agree very closely 
with those obtained in Experiment 7, except in the case of ash. This 
difference is probably explained by the fact that the stock -came from 
widely scattered beds, and the inorganic constituents were probably 
dissimilar. 
