62 THE CANNING OF FOODS. 



There are five general classes of canned marine products, viz, (1) plain 

 boiled, steamed, or otherwise cooked; (2) preserved in oil; (3) prepared with 

 vinegar, sauces, spices, jellies, etc.; (4^ cooked with vegetables, etc.; and 

 (5) preserved by some other process, but placed in cans for convenience in 

 marketing. 



The first class includes salmon, mackerel, herring, menhaden, cod, halibut, 

 smelt, oysters, clams, lobsters, crabs, shrimp, green turtle, etc. ; sardines almost 

 exclusively make up the second class. 



The third class includes various forms of herring prepared as " brook trout," 

 "ocean trout," etc., mackerel, eels, sturgeon, oysters, lobsters, crabs, etc. 



The fourth class includes fish chowder, clam chowder, codfish balls, green 

 turtle stew, terrapin stew, and devilled crabs. 



The fifth class is made up of smoked herring, halibut, haddock, carp, pick- 

 erel, lake trout, salmon, eels, sturgeon, etc., and brine salted mackerel, cod, 

 and caviar. 



CRABS . ( CALLINECTES H ASTA ) . 



Canned crab meat in this country was the result of experiments 

 made by James McMenamin, of Norfolk, Va. He began at Norfolk 

 in 1878, but moved to Hampton in 1879, and that has been the chief 

 point of supply up to the present time. The season for catching crabs 

 is from April to October. 



The live crabs are placed in large crates, well washed, and then run 

 into a steam box, where they are cooked for 25 minutes. After 

 cooling they are " stripped " that is, the shell, viscera, and smaller 

 claws are removed. The meat is then picked out of the bodies 

 and large claws by hand, or it may be removed by centrifugal force 

 or by compressed air. The latter methods, which are of recent origin, 

 are effective and save much labor. In the centrifugal method the 

 shell and claw are cut across to expose the cells and a quantity so 

 prepared is placed in a centrifugal drum, almost the same as that 

 used for drying in a laundry. The drum is made to spin at a high 

 speed and all the meat is extracted. The compressed-air method 

 consists of an air compressor and a storage tank, with pipes leading 

 to a nozzle. The shell is held in front of the nozzle, the air is turned 

 on, and the meat blown out. Either method is faster, better, and 

 cleaner than the hand picking. 



The meat is filled into cans and processed. The No. 1 cans gen- 

 erally used are first heated for a half hour in boiling water, vented, 

 and then processed for 35 minutes at 240 F. 



Crab meat is not so easy to keep as some other kinds, the tendency 

 being to blacken more or less in the cans. 



OYSTERS. 



The oyster is a marine bivalve of the genus Ostrea, the species used 

 in this country being Ostrea virginiana. It is found along the coast, 

 chiefly in the shallow waters at the mouths of rivers and in bays. 

 Chesapeake Bay has long been noted for the abundance of its oysters. 

 They are found naturally all along the Atlantic coast as far north as 



