737 
CHEMICAL COMPOSITION 
OF FOOD-F’JnLS. 
Table 9 .— Composition of American fishes. Specimens as received for analgsis, includ- 
ing both flesh (edible portion) and refuse — Continued. 
In whole or dressed fish as 
analysis. 
taken 
for 
1 
© 
1 
— 
Edible portion. 
© 
& 
a i 
a 
o 
^5 
3 
I © 
1 
; | 
Nutrients! 
Names of fish and portions analyzed. 
Salt. 
© 
6 
1 25 
>> 
u 
o 
(S 
3 
.© 
a 
Hi 
Refuse : Entrails, 
skin, etc. 
l 2 
£3 
.2 
© 
2, 
3 
§ | 
; a; 
1 
! Water-fre-. substa 
(nutrients). 
■3? 
'3 a 
Is 
s 
d 
8 
CD 
S 
l 
g 
© 
.2 
Preserved Pish— Continued. 
Salmon (Oncorhynchus chouicha) 
2.2 
96 
P. ct. 
0.0 
P. ct. 
97.8 
P. ct. 
1 62. 2 
P. ct. 
■5.6 
P.ct. 
19.7 
P. ct. 
14.6 
P.c. 
1.3 
Do 
0.4 
241 
0.0 
99.6 
56.6 
42.0 
19.2 
21.5 
1.3 
Do (average of 3 specimens) . . 
1.0 

3.9 
95.1 
59. 3 
35.8 
19.3 
15.3 
1.2 
Mackerel (Scomber scombrus) 
1.9 
94 
0.0 ! 
98.1 
68.2 
29.9 
19.9 
8.7 
1.3 
Saltmackerel (Scomber scombrus), “No. 2mack- 
erel” 
7.9 
95 
17.0 
75.1 
35.8 
39.3 
14.0 
23.2 
2.1 
Do 
8.7 
219 
22.4 
68.9 
33.8 
35.1 
13.7 
19.3 
2.1 
Do (average of 2 specimens) . . 
Tunny, “Horse mackerel” (Orcynus secundi- 
8.3 
19.7 
72.0 
34.8 
37.2 
13.8 
21.3 
2.1 
dorsalis) 
0.0 
240 
0.0 
100.0 
72.7 
27.3 
21.5 
4.1 
1.7 
Smoked haddock (Gradus segleflnus) 
5.6 
275 
0.0 
94.4 
68.7 
25.7 
2i.8 
2.3 
1.6 
5. PROTEIN IN THE FLESH OF FISHES. 
ERRORS INVOLVED IN THE COMMON METHOD OF ESTIMATION. 
( 
In the tables in division 3 Of this section, which give the results of 
analyses of specimens of the flesh of fishes^the percentages of protein 
as estimated by multiplying the nitrogen by the factor 6.25, and those 
of “ albuminoids, etc.” (actual nitrogenous substances), as estimated 
by difference [100 — (ether extract ash) = “ albuminoids, etc.”], are 
both given. In the tables which recapitulate the analyses these fig- 
ures for u albuminoids by difference ” are taken for the nitrogenous 
matters. 
It will be interesting to observe the differences between results 
obtained by estimating the nitrogenous substance by these two methods 
(see remarks on “ Nitrogen, Protein, etc.,” under Methods of Analysis, 
above). If we leave the carbohydrates out of account/ eaSume the ash 
to represent the mineral matters, and take ether extract as represent- 
ing the fats, but as including no nitrogeuized fats, then the figures for 
“albuminoids, etc., by difference ” will represent exactly the amount 
of nitrogenous substance (albuminoids, gelatinoids, nitrogenous extract- 
ives, and nitrogeuized fats). Of course, these assumptions are not abso- 
lutely correct. The flesh contains a minute quantity of carbohydrates 
(including all non-nitrogenous organic substances other than fats) ; 
the ash is not the exact measure of the mineral matters, and the ether 
extract does not exactly represent the neutral fats. But the errors 
involved are small, and until better methods of analy 's are devised 
H. Mis. 274 47 
