52 THE WONDERFUL HOUSE THAT JACK HAS 



just to furnish us sport, or do they serve a more useful 

 purpose as well? On the average, they are composed 

 of from seven-tenths to eight-tenths water, one-tenth 

 to two-tenths proteid, one-twentieth to one-tenth fat, 

 and one one-hundredth to two one-hundredths mineral 

 matter. We can see they contain a good proportion 

 of the necessary building materials. This, together 

 with the fact that they are not difficult to digest, 

 makes them an excellent substitute for meat. 



Fish caught in cold, clear, or running water are 

 usually preferable to those from stagnant, shallow, or 

 warm water. The kinds living in streams having a 

 rocky' or sandy bottom are, as a rule, better than those 

 found in streams having muddy bottoms. Fish should 

 be killed as soon as caught. Allowing them to die 

 slowly not only is cruel, but also, according to some 

 authorities, makes the quality of the flesh less desir- 

 able. Some fish become soft and flabby when streams 

 grow warm in summer, and should never be eaten in 

 that condition. 



The flesh of fish that die in the water from various 

 causes is spongy and yellowish, and has a foul odor. 

 Decaying fish also have a disagreeable odor, are bluish 

 in the under part, and feel flabby and sticky. Of 

 course these should not be eaten. Fish that have been 

 frozen and kept for a time after being thawed out are 

 especially likely to contain poisons called ptomaines. 

 If the water in which fish is being washed or boiled 

 blackens silver, we may be sure it is not fit to eat. 



