INTRODUCTION 



Cold is the nearest approach to an ideal preservative that we have. 

 It has been employed from the most ancient times for preserving 

 foods, jars of milk and butter in cool spring water, meats exposed 

 to outside temperatures in winter, and melons and fruits in cool 

 caves and cellers being ancient examples; but it was only with the 

 development of machinery for producing and controlling cold arti- 

 ficially, beginning in the latter part of the last century, that cold was 

 applied systematically and in a large way to the preservation of 

 perishable foods. During the greater part of the time since the 

 first practical ice machine was invented, attention and scientific study 

 have been concentrated on the perfection of mechanical means of 

 producing cold rather than on the best methods of utilizing cold to 

 preserve various classes of foods. This order of progress is natural 

 and logical, but the time has arrived when study is being directed 

 more specifically to the best methods of applying cold to keep the 

 various kinds of perishable commodities. The aim of this paper 

 is to present and discuss the application of refrigeration to fish and 

 sea foods as a special class in which sufficient progress has been 

 made in recent years to justify such a presentation. 



FUNCTION OF REFRIGERATION IN THE FISH INDUSTRY 



Before artificial refrigeration was used as a method of preserving 

 fish they were dried, salted, or pickled, and later were canned; but 

 fish preserved by any of these methods are greatly changed and are 

 suitable for special purposes only. They do not at all meet the 

 demands for fresh fish. Refrigeration is the only method of pre- 

 serving that keeps fish in essentially its original condition over long 

 periods and during transportation over long distances. 



Perhaps few who are not directly connected with the fish industry 

 fully realize the importance of refrigeration in the distribution of 

 fish to the consumer. Fish are highly perishable ; yet if there were a 

 regular and dependable supply, and if the demand for fish were also 

 steady and continuous, there would be little need for artificial refrig- 

 eration. But both supply and and demand are highly irregular. 

 Nearly all fishes are migratory ; they have their seasons of abundance 

 and scarcity; weather influences the capture and chance plays an 

 important part in locating the schools of fish. Many fishes, like the 

 mackerel, may be taken in diminishing numbers from year to year, 

 and then, all of a sudden, appear in tremendous abundance, choking 

 the market and demoralizing prices. 



The demand for fish also is subject to marked fluctuations because 

 of social, racial, and sectarian customs. In summer, when fish are 

 generally abundant and the weather is fair, the popular demand 

 declines and fish move much more slowly in the markets than they do 

 in winter. In the Lenten season often more fish are demanded than 



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