452 REPORT OF COMMISSIONER OF FISH AND FISHERIES. [20] 



Composition of fat and spent salmon, whole fish. 



Eecapitulation. Percentages of flesh, water-free substance, and nutrients in fat and spent 



salmon. 



Salmon. 



In flesh : 



Fat 



Spent 



In whole fish 



Fat 



Spent . - - 



Flesh, 

 edible 

 portion. 



Per cant. 

 100.0 

 100.0 



61.5 

 56.4 



Water- 

 free sub- 

 stance in 

 flesh. 



Per cent. 

 38.8 

 23.2 



23.9 

 13.1 



In water-free substance. 



Protein. 



Per cent. 

 24.3 

 18.5 



15.0 

 10.4 



Fats. 



Per cent. 



13.1 



3.6 



8.0 

 2.0 



Ash. 



Per cent. 

 1.4 

 1.1 



0.9 

 0.7 



In the above statements the protein is estimated by difference, as ex- 

 plained in the description of methods of analysis, and, the discussion of 

 the nitrogen factors of the protein. Some differences in the composition 

 of the nitrogenous constituents of the flesh are brought out by the fol- 

 lowing figures, which will be made clear by reference to the discussion 

 of the nitrogen factors referred to. 



The figures show (1) the percentages of protein as estimated by mul- 

 tiplying the nitrogen by 6.25; (13) the sum of the percentages of 

 protein thus estimated + fats + ash + water; (3) the percentage of 

 protein as computed by subtracting the sum of water + fats -\- ash 

 from 100, "protein by difference"; (4) the nitrogen in the flesh, and (5) 

 the "nitrogen factors," obtained by dividing the percentage of " protein 

 by difference" by the nitrogen. 



In flesh of salmon. 



(1) Protein, N X 6.25 percent.. 



(2) Protein, N X 6.25, + fat + ash + water do 



(3) Protein bv difference do 



(4) Nitrogen 'in (3) do 



(5) Nitrogen factor 



Professor Miescher has shown that in the Ehine salmon the develop- 

 ment of the reproductive organs is done entirely at the expense of the 

 other organs and tissues, or, to be more specific, at the expense of the 

 albuminoids and fats of the flesh; the fish taking no food during its so- 



