CHEMICAL COMPOSITION OF FOOD-FISHES. 
853 
the oysters experienced, may be estimated either by comparing the per- 
centages found by analysis before and after dialysis or by comparing 
the absolute weight of a given quantity of flesh and the weights of 
each of its ingredients before with the weights of the same flesh and 
of its ingredients after dialysis. For the estimate by the first method 
we have simply to compare the results of the analyses of the floated 
and the not-floated specimens. Taking the averages of the two experi- 
ments, it appears that : 
The percentages of— 
Water rose from 
Water-free substance fell from 
Before 
dialysis. 
11 . 9 to 
22. 1 to 
After 
dialysis. 
82.4 
17.6 
100.0 
100.0 
Protein (N X 6.25) fell from 
Fat (ether extract) fell from 
Carbohydrates, etc., fell from 
Mineral salts (ash) fell from 
10. 5 to 
2. 5 to 
6.9 to 
2.2 to 
8.9 
1.9 
5.2 
1.6 
22.1 
17.6 
There was, accordingly, a gain in the percentage of water and a loss 
in that of e*ach of the ingredients of the water-free substance. 
It is more to the point to note the actual increase and decrease in 
amounts of flesh and its constituents, the absolute gain or loss of each 
in the floating. The estimates (see table, page 812) make it appear that 
100 grammes of the flesh as it came from the salt water was increased by 
floating, in one specimen, to 120.9, and in the other to 113.4 grammes. 
This is equivalent to saying that the two specimens of flesh gained in 
the floating, respectively, 20.9 and 13.4 per cent., or, on the average, 
17.3 per cent, of their original weight. By the same estimates the 
water-free substance in the 100 grammes of flesh before the floating 
weighed, on the average, 22.1 grammes, while that of the same flesh 
after dialysis weighed only 20.6 grammes, making a loss of 1.5 grammes 
or 6.6 per cent, of the 22.1 grammes which the water-free substance 
weighed before dialysis. The main results of the two experiments 
thus computed, may be stated as follows : 
In the u floating ” of 100 grammes of flesh (body) of the oysters : 
Before After 
The weight (in grammes) of— dialysis. dialysis. 
Water rose from 77. 9 to 96. (i 
Water-free substance fell from 22. 1 to 20. 6 
Whole flesh rose from 100. 0 to 117. 2 
Protein was assumed to remain the same 10. 5 to 10. 5 
Eat (ether extract) fell from 2. 5 to 2. 3 
Carbohydrates, etc., fell from 6. 9 to 6. 0 
Mineral salts (ash) fell from 2. 2 to 1. 8 
22. 1 to 20. 6 
