PRODUCTS FROM THE SEA 343 



according to size, in strong brine. It is afterwards 

 smoked for a night. 



These methods of salting and smoking fish do not apply- 

 only to herring, and large quantities of such fish as haddock 

 and cod are similarly treated. 



Another method of preserving fish is to tin them in 

 oil. In this way sardines, which are young pilchards, are 

 prepared for market by the French. The fish are cleaned, 

 immersed for a short time in brine, dried and then fried 

 for about two minutes in olive oil. They are then packed 

 in olive oil in tins which are hermetically sealed. A similar 

 trade is carried on in Norway only there the " sardine " 

 is either a sprat — " Brisling " — or a young herring. 



In some countries sardines or other fish may be pickled 

 in vinegar. Fish are used in some European countries 

 for making sausages, and are mixed with pork and flour. 



Products from Fish 



There are many commercial by-products to be obtained 

 from fish, chief amongst which are certain oils, fertilizers 

 and meals, glue, isinglass and leather. 



Fish may be divided into two classes, those that contain 

 most oil in their bodies and those that have most in their 

 livers. Of the former the herring, the menhaden and the 

 salmon are good examples and they furnish what is com- 

 mercially known as " fish oil." This oil is used to a large 

 extent in the manufacture of paints. To the latter group 

 belong such fish as the cod, which yield those " liver oils " 

 so well known for their medicinal value. Cod-liver oil, 

 as well as that of other fish such as the shark, is used in the 

 tanning industry for " currying " leather — making it water- 

 proof and pliable. It is also used in the manufacture of 

 soaps and for tempering steel. 



In the manufacture of fish meal all the waste parts of 



