CHEMICAL COMPOSITION OF FOOD-FISHES. 
847 
Tables XVI . — Composition of flesh (edible portion) of crustaceans and turtles. 
Names and localities of specimens. 
Laboratory No. j 
H 
© 
Specimen 
received. 
In water-free substance. 
Nitrogen. 
; Protein (N X 
6.25). 
| Fats (ether 
extract. ) 
Ash. 
Protein, fats, 
and ash. 
Albuminoids 
(by differ- 
ence). 
Lobster (Homarus americanus) : 
P.ct. 
P. ct. 
P. ct. 
P. ct. 
P.ct. 
P.ct. 
Maine - - 
50 
Mar., 1881 
1.86 
11. 63 
1.82 
1.63 
15.08 
12. 25 
Do 
62 
Apr., 1881 
2. 24 
14. 05 
1.55 
1.71 
17.31 ! 
14. 97 
Do 
239 
Apr., 1882 
2. 76 
17. 24 
1.45 
1.62 
20.31 
17.76 
Massachusetts 
69 
May, 1881 
2. 41 
15. 03 
2.54 
1. 87 
19. 44 
13. 48 
Average of 4 specimens 
2.32 
14.49 
1.84 
1. 71 
18. 04 
14. 62 
Lobster, canned : 
Maine ... . . . ...... . ... 
76 
2. 68 
16. 75 
0. 46 
2.78 ' 
19.99 i 
17. 40 
Bo 
121 
3. 12 
19. 52 
1.68 
2. 15 
23.35 
20. 02 
Average of 2 specimens 
2. 90 
18. 13 
1. 07 
2. 47 
21. 67 ; 
18.71 
Crayfish : 
Potomac River, Va 
64 
Apr., 1881 
2. 56 
16.00 
0.46 
1.31 
1 17.77 
17.01 
Crab (Callinectes hastatus) : 
New Jersey 
101 
Nov., 1881 
2. 66 
16: 64 
1.96 
3. 13 
21.73 
17.84 
Crab, canned : 
TTfimyitnn Va, 
124 
2. 50 
15. 62 
0. 79 
1. 78 
18.19 
16. 45 
Bo ’ 
274 
2. 56 
15. 98 
2. 30 
2.10 
i 20.38 
16. 65 
Average of 2 specimens 
2. 53 
15.80 
1. 55 
1.94 
19. 29 
16. 55 
Shrimp, canned : 
frlllf ftf 
123 
4. 06 
25. 38 
1. 00 
2. 58 
28. 96 
25. 62- 
Terrapin : 
Savannah, Ga 
235 
Apr.,. 1882 
3.40 
21.23 
3.47 
1. 02 
25. 72 
' 21. 04 
Green turtle (Chelonia mydas) : 
Key West, Fla 
272 
May, 1882 
3. 17 
19. 84 
0. 53 
1. 20 
21. 57 
18.49 
4. FLOATING OF OYSTERS. 
Not every lover of the oyster knows that the size and plumpness 
which are so highly prized in the great American bivalve, and which 
are scr attractive in specimens on the half-shell or in the stew as to lead 
the average man to pay a considerable extra price for extra size, are 
not entirely natural ; and even those who do know that the majority 
of the oysters in the market are artificially swollen by introducing 
water into the tissues are not all aware that the process by which this 
is done is closely analogous to that by which the food in our bodies is 
conveyed through the walls of the stomach and other parts of the diges- 
tive apparatus and poured into the blood and lymph to do its work of 
nourishment. 
Physiologists are, I believe, agreed that the passage of the digested 
food through the walls of the alimentary canal in man and other ani- 
mals is, in large part, due to osmose or dialysis, and that the operation 
of this physical law is a very common one in the animal body. But the 
quantitative study of the chemical changes involved is generally ren- 
dered difficult or impossible by the very fact of their taking place in 
living animals where the application of chemical analysis is impossible; 
an opportunity is, however, offered by the oyster, which, since it lives 
in water and has a body so constituted as to readily permit the inflow 
and outflow of water and solutions of salts, may be easily used for 
* The substance of this chapter was printed in the Report of the Oyster Investigation 
and Shellfish Commission of New York, for 1887. 
