854 REPORT OF COMMISSIONER OF FISH AND FISHERIES. 
Estimating the increase or decrease of weight of each constituent in 
per cent, of its weight before floating, the water gained 23.9 per cent.; 
the water -free substance lost 6.G percent.; the whole flesh (body) gained 
17.3 per cent. The protein was assumed to neither gain nor lose. The 
fat lost 8.8 per cent. ; the carbohydrates, etc., lost 12.5 per cent. ; the 
mineral salts lost 15.5 per cent. 
According to these computations the flesh lost between one-sixth and 
one-seventh of its mineral salts, one-eighth of its carbohydrates, and 
one-twelfth of its fats, but gained enough water to make up this loss 
and to increase its whole weight by from one seventh to one-fifth. 
These estimates are based on the assumption that the amount of pro- 
tein (N x 6.25) in the flesh remained unchanged during the floating. 
It seems probable, however, that the flesh may have lost a small 
amount of nitrogenous material. If this was the case the actual gain 
of flesh and of water must have been less and the loss of fats, carbo- 
hydrates, and mineral salts greater than the estimate makes them. But 
there appears to be every reason to believe that the error must be very 
small, and since it would affect all the ingredients in the same ratio, the 
main result, namely, that there was a large gain of water and a consid- 
erable loss not only of mineral salts but of fats and carbohydrates as 
well, can not be questioned. 
CHANGES IN THE COMPOSITION OF THE LIQUID PORTION. 
3. The liquids might be expected to receive material from the flesh 
and to yield material to the surrounding water. The materials received 
from the flesh would be such as the latter parted with by osmose or 
secretion. Those yielded to the water would either escape by diffusion 
or be washed away when the shells were open wide enough. Compar- 
ing the percentage composition of the liquids before and after floating, 
as shown by the averages of the analyses in the two experiments, it 
appears that : 
The percentages of— 
Water rose from 
Before 
dialysis. 
. . . . 94. 9 
to 
After 
dialysis. 
95.5 
Water-free substance fell from. . . 
5. 1 
to 
4.5 
Protein (N X 6.25) rose 
100.0 
1.9 
to 
100.0 
2Tl 
Carbohydrates, etc., rose 
Mineral salts, (ash) fell 
0.7 
to 
1.1 
2.5 
to 
1.3 
The increase in the percentage of water and the decrease in that of 
mineral salts are very marked. The quantities of fats (ether extract) are 
too small to be taken into account. The increase of pitrogen and that 
of carbohydrates, though absolutely small, are nevertheless outside the 
limits of error of analysis, and must, like those of the salts, represent 
actual changes in the composition of the liquids. 
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