408 THE CANADIAN NATURALIST. [Yol. ix. 



much practical interest. In 100 pounds of the flesh of fresh 



cod we have 83 pounds of water and only 17 pounds of solids, 



while the flesh of the salmon contains only Q6^ per cent, of 



water and 33J per cent, of solids : that is to say, about one-sixth 



of the flesh of cod and one-third of that of salmon consists of 



solids, that is, of nutritive substances, the rest being water. 



Lean beef, free from bone, contains about seventy-five per cent. 



water and twenty-five per cent, solids. The figures for some of 



the more common sorts offish were: — 



Solids. Solids. 



In flesh of per cent. In flesh of per cent. 



Flounder 17.2 Halibut, fat 30.7 



Cod 16.9 Mackerel -2.2 



Striped bass 20.4 Shad 30.7 



Bluefish 21.8 Whitefish 30.4 



Halibut, lean 20.6 Salmon 33.6 



If we take into account not the flesh only, but the whole fish 



as sold in the market, including bones, skin and other waste? 



the actual percentage of nutritive material is, of course, smaller. 



Thus the following percentages of edible solids were found in 



samples analysed : — 



Flounder 7.1 Shad 14.8 



Ccd 10.5 Shad 18.7 



Mackerel 11.4 Lake trout 13.6 



Halibut, lean 15.6 Salmon 25.6 



Halibut, fatter 27.2 



This subject has of late attracted unusual attention. The 

 chemico-physiological investigation of the past two decades has 

 brought us where we can judge with a considerable degree of 

 accuracy, from the chemical composition of a food-material, 

 what is its value for nourishment as compared with other foods. 

 The bulk of the best late investigation of this subject has been 

 in Germany, where a large number of chemists and physiologists 

 are busying themselves in the experimental study of the laws of^ 

 animal nutrition. They have already got so far as to feel them- 

 selves warranted in computing the relative values of our common 

 foods, and arrange them in tables, which are coming into popu- 

 lar use. The valuations are based upon the amounts of albumi- 

 noids, carbohydrates and fats, each being rated at a standard, 

 just as a grocer makes out his bill for a lot of sugar, tea and 

 000*06, by rating each at a certain price per pound, and adding 

 the sums thus computed to make the whole bill. A table was 



