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BULLETIN OF THE UNTI’LI) STATES FISH COMMISSION. 
REFRIGERATION, OR PRESERVATION BY LOW TEMPERATURE. 
The temperature of fish, unlike that of mammals and other warm-blooded animals, 
corresponds to that of the medium in which they live. The atmosphere during the 
day being usually warmer than the seas and rivers the temperature of fish is generally 
increased on their removal therefrom and their consequent death, whereas in case of 
most land animals death usually results in a decrease in the temperature. This increase 
in temperature, together with the delicacy of the texture of flesh and the very large 
number of bacteria in the atmosphere to which the flesh is unaccastomed, makes fish 
extremely susceptible to i)utrefaction soon after life is extinct, especially if there be 
considerable moisture in the stomach cavities. In order to overcome this tendency 
it is important, in case fish are to be used fresh, that the temperature be kept at a low 
])oint while they are awaiting consumption. As the markets are generally situated at 
some distance from the sources of supply, preservation for a short time is a necessity, 
and for this purpose the application of low temperature is so general that it is almost 
coextensive with the fresh-fish trade in this country. 
The importance of this method of preserving fish is not readily overestimated. 
It has resulted in a wonderful development of the Gulf and South Atlantic fisheries; 
and, indeed, without its agency the fishery resources of those regions would be of 
comparatively little value. It has enlarged and widened the general fishery trade 
so extensively that at present salmon fresh from the Columbia Kiver, halibut from 
Alaskan waters, and oysters from Chesapeake Bay and Long Island Sound, are sold 
throughout the United States and in foreign countries, and nnmerous other fishery 
products are marketed thousands of miles from the source of supply, and for weeks 
after their capture, in condition not dissimilar to that when removed from the water. 
It is only within the last half century that much attention has been given to the 
fresh-fish trade. Prior to 1830 it was of very limited extent, being confined during 
the warm months to a retail business in the towns near the fishing ports, while in 
winter the fish were frozen naturally and transported to the neighboring markets, 
the business being largely in the control of peddlers. Following the introduction of 
ice, about 1830, the handling of fresh fish developed more extensively than any other 
branch of the fishery industries, and at present the quantity of fish marketed fresh 
in the United States is much greater than the quantity placed on the market in all 
other conditions. The increase in this trade is one of the most noticeable features 
in connection with the fishery industries. An important factor in developing and 
maintaining it is the improvement in transportation facilities — not only on shore but 
also in bringing fish from the sea to the fishery ports, the improvements in railway 
tralfic, and the addition of fast types of vessels. This feature of the trade, however, 
is scarcely within the scope of the present paper, as it does not tend to preserve the 
product, although it serves better than methods of preservation. 
