CHAPTER XIX 

 FISHES AND MANKIND 



Fish as food. Composition of flesh. Value of fresh-water fishes. Different 

 kinds of edible fishes. Commercial value of deep-sea fisheries. Fishing 

 industry of Great Britain. Fishing methods: trawling, seining, drifting, 

 lining. Preservation of fresh fish. Fish curing, etc. By-products of 

 fishes: oils, meals, fertilisers, glue, isinglass, leather, etc. 



As a staple article of food, fish must have found favour with man 

 at a very early stage of his history, and there can be very few 

 races living to-day who do not include this valuable protein 

 food in their ordinary diet. Whether eaten raw, as in Japan 

 and the Hawaiian Islands, cooked, salted, smoked, or preserved 

 in one way or another, the popularity of fish-flesh is world- 

 wide. Apart from certain species whose flesh is watery, dry, 

 and tasteless, full of small bones, or heavily charged with rank 

 oils, the flesh of fishes is generally white and flaky, and has an 

 agreeable flavour. In the ease with which its contained proteins 

 and fats are digested by the human body, it compares very 

 favourably with beef or other meats, and it has been shown 

 that man is able to digest completely as much as 93*2 per cent, 

 of the protein content of tinned Salmon, and 93*1 per cent, of 

 that of fresh Mackerel, and can make use of 93*7 per cent, 

 and 95-2 per cent, respectively of the fatty content of the same 

 fishes. 



The muscular tissue or flesh of a fish is made up of 60 per 

 cent, to 82 per cent, water, about 13 per cent, to 20 per cent, 

 proteins, and a greater or lesser amount of fat. The following 

 table illustrates the percentages of these substances in the flesh 

 of some of our commoner food-fishes, and the figures in the 

 fourth column represent the "energy value" or "fuel value" 

 expressed in calories. Calories are nothing more than measure- 

 ments of heat, and provide a simple means of comparing one 

 article of food with another in terms of its energy value, which 

 may be briefly defined as "the number of calories of heat 

 equivalent to the energy which it is assumed the body would 

 be able to obtain from one pound of given food material, 

 provided the nutrients of the latter are fully digested." 



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