NUTRITIVE VAIiUE OF FISH AND SHELLFISH 



543 



Table 21. — Total ash, phosphorus, and sulphur in the edible portion of some 

 common American fish and shellfish 



The figures in Table 21 representing ash show that fish, as a rule, 

 contains on the average somewhat more than 1 per cent of ash and 

 about one-half of 1 per cent each of phosphorus and sulphur cal- 

 culated as oxides. Shellfish contain nearly twice as much ash as 

 true fishes. This is in part due to the iron stored in the fiver and in 

 part to the calcium in the mantle (of moUusks), wliich, being the 

 tissue from which the shell is secreted, is heavily charged with 

 mineral salts. The figures in this table were taken from Atwater 

 (1892) and Dill (1921). 



Table 22. — Percentage of mineral elements in flesh of various animals 



Man 



Pig 



Ox 



Calf 



Rabbit.. 



Hen 



Frog 



Haddock 



Eel 



Pike 



Water 



7Z63 

 72.89 

 75.80 

 75.39 

 76.83 

 68.38 

 81.62 

 80.64 

 63. 10 

 79.38 



It will be noticed in Table 22 (taken from Katz, 1896) that fish, 

 with respect to mineral constituents, is richer in calcium than other 

 flesh foods. It is relatively low in iron because it does not retain 

 hemoglobin of the blood in the muscle, for example, as the flesh of 

 the ox does. 



Although iodine probably exists in the living fish only in organic 

 combination, it remains in the ash upon combustion and in this sense 

 may be classified with the mineral substances present. In Table 



