CHEMICAL COMPOSITION OF FOOD-FISHES. 739 
Id brief, while the error involved in estimating the total nitrogenous 
substance by multiplying the nitrogen by the factor 6.25 in the usual 
way, is, when viewed from the exact scientific standpoint, very consid- 
erable in many cases, it is seldom large enough ro be of great practical 
importance. The exceptional cases, however, demand further study. 
Sum of protein ( N x 6.25), ether extract, *ash, and water in the flesh of specimens of 
American flshes. 
Protein -f 
ether ex- 
tract-fash 
in water- 
free sub- 
stance. 
Averages. 
Lab. 
No. 
Name. 
Protein -f- 
ether ex- 
tract +ash 
-f water 
in flesh. 
Protein + 
ether ex- 
tract-fash 
in water- 
free sub- 
stance. 

Protein -f 
ether ex- 
tract-fash 
-f water 
in flesh. 
40 
41 
36 
35 
81 
236 
15 
31 
262 
127 
208 
110 
98 
Per cent. 
97.01 
98. 00 
99. 15 
99. 61 
99.74 
100. 18 
99. 94 
100. 16 
100. 57 
•99. 55 
101. 04 
100. 30 
100. 32 
100. 15 
100.72 
100. 48 
100. 5$ 
100. 61 
100. 62 
100. 60 
100. 70 
100. 70 
100. 77 
100. 74 
100. 75 
100.53 
101.02 
100. 81 
100,81 
100. 84 
100. 18 
101.19 
101. 30 
100.45 
100. 68 
100. 74 
100. 87 
100. 96 
101.28 
Per cent. 
99. 34 > 
99. 59 5 
99. 82 > 
99. 91 5 
99. 95 
100. 05 
99. 98 ) 
100. 05 > 
100. 14 ) 
99. 91 > 
• 100.22 5 
100. 08 
100. 07 
100. 03 \ 
100.14 5 
100. 09 
100. 14 
100. 16 
100. 18 
100. 20 \ 
100. 15 5 
100. 18 i 
100. 20 5 
100. 13 
100. 16 
100. 14 \ 
10C. 30 5 
100.21 
100. 15 
100. 16 
100. 04 ) 
100. 28 > 
100. 38 ) 
100. 12 1 
100. 16 1 
100. 21 | 
100. 22 > 
100. 25 1 
100. 36 | 
Per cent. 
Per cent. 
97. 50 
99.47 
99. 38 
. .T.do - 
99. 87 
Pollock 
100. 22 
100. 06 
do 
100. 29 
100. 13 
Cusk - 
100 
224 
258 
111 
126 
100. 43 
do - , 
100. 09 
Small-mouthed red-horse 
1 
j- ' 
Cisco 
Mullet 
90 
234 
263 
220 
5 
Butter-fish . . _ 
Pompano 
100. 65 
100. 18 
do - 
Ale wife 
100. 73 
- » 
do 
100. 19 
113 
52 
Hake 
Pike perch, wall-eyed pike. 
217 
4 
Salt-water eel 
100. 77 
100. 22 
do 
91 
238 
Small-mouthed black bass 
Sturgeon 
99 
Tomcod - 
1 
211 
9 
Halibut 
...do 
100. 89 
100.28 
do 
221 
Shad 
245 
10 
...do 
do 
249 
do - 
100. 91 
100. 27 
32 
do 
212 
— do 
6 
do - 
101.37 
100. 92 
100. 63 
101. 32 
100. 97 
101. 01 
100. 67 
100. 73 
100. 77 
100. 88 
100. 96 
102. 03 
100. 93 
100. 95 
100. 98 
101. 62 
101. 12 
99. 17 
103. 09 
100. 75 
101. 03 
101. 72 
101. 29 
100. 39 J 
ICO. 20 
| 100. 15 l 
100. 32 5 
100. 30 » 
100. 30 5 
100. 16 ) 
100. 16 j 
' 100. 16 
100. 21 { 
100. 24 | 
100. 43 J 
100. 20 \ 
100. 17 ( 
100. 20 ( 
100. 37 J 
100. 20 
99. 82 ( 
100. 62 5 
100. 17 ) 
100. 27 V 
100. 35) 
100. 28 
53 
46 
Large-mouthed black bass. 
White perch - 
100. 97 
100. 24 
44 
17 
255 
do . 
Lake trout 
100. 99 
do 
100. 30 
260 
Striped bass 
1 
248 
....do 
225 
do 
101. 00 
100. 23 
237 
do 
19 
do 
7 
do 
269 
Black fish 
205 
do 
101. 12 
100. 24 
244 
do 
38 
do 
270 
Red bass ....... 
207 
Smelt 
23 
....do 
101. 13 
100. 22 
24 
256 
Brook trout 
do 
101. 17 
i 100. 26 
254 
do 
252 
Kingfish 
1 
1 _ 
