THE PRESERVATION OE EISHERY PRODUCTS EOR ROOD. 
By Charles H. .Stevensox 
INTRODUCTION. 
Methods of preservation are of constantly iucreasiny' importance to the prosperity 
of the fisheries — more so, perhaps, than to any other food-snpplying industry. In 
agricnltnre, cereals are cared sufficiently in the open air to keep for indefinite periods; 
vegetables and frnits with X)roper care will generally remain in edible condition long 
enough to reaxh distant markets, and some will last until the following season; the 
domestic animals intended for food may be transported alive to the place of marketing 
and there slaughtered; but, under ordinary conditions, fishery products are subject 
to rapid putrefaction after removal from the water. 
It is now a generally accepted opinion that all putrefaction is caused by the devel- 
opment of living organisms known generally as bacteria or putrefactive germs, this 
theory being announced first in 1837 by the German physiologist, Theodore Schwann. 
“Putrefaction,” says Cohn, “begins as soon as bacteria, even in the smallest numbers, 
are introduced, and xirogresses in direct proportion to their multixfiication.” In living- 
animals there is a tendency to counteract the develoxunent of these germs, and main- 
taining marine animals alive is the simplest form of preservation, although rarely the 
most economical. After life is extinct, heat, moisture, and air are all more or less neces- 
sary to the develojunent of bacteria, and it is xirincipally by removing one or all of 
these factors that xireservatiou is accomxdished. This gives us three xu-incipal 
methods of preserving dead fish, viz: Eefrigeration, which diminishes the heat; desic- 
cation or drying, which decreases the moisture; and canning, which separates the 
preserved jiroduct from the air. Another method of great importance is the axiplica- 
tion of antisexitics, such as salt, vinegar, etc., this x>rocess being known generally as 
pickling. Other forms of preservation, the most important of which is smoking, par- 
take of the characteristics of the preceding with the addition of further treatment 
for the XBirpose of flavoring. These six processes, viz, preserving alive, refrigeration, 
desiccation, canning, xiickliBg, and smoking, include x^ractically all the general 
methods of xJreserving fishery foods. 
The qualities of the original products, however, are so varied and subject to such 
delicate influences that a xirocess well adaxited to the x)reservatiou of one article may 
be impracticable or deleterious when axixilied to another, even of the same class. 
Thus it would not do to refrigerate salmon, herring, and oysters in the same manner; 
nor is the x>rocess of salting codfish, halibut, herring, and swordfish the same. The 
manner of preservation also differs according to the marker for Avhich the article is 
intended. Codfish destined for the New England market would not be statable for the 
Gulf States, and that for the West Indies and Brazilian trades requires still different 
F, 0. n., 1898—2-2 
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