10 THE CANNING OF FOODS. 



fishing ports. In 1845 the canning of sardines was begun in France; 

 in fact, the early products were nearly all sea foods. 



The first canner in this country was Ezra Daggett, who learned the 

 trade abroad. He and Thomas Kensett packed a few salmon, lob- 

 sters, and oysters in New York in 1819. The next year William 

 Underwood and Charles Mitchell began operations and a factory 

 was opened in Baltimore. In 1839 Isaac Winslow began experiment- 

 ing with the canning of corn in Portland, Me. His early efforts were 

 mostly failures, but he had a persistence worthy of any cause, and 

 by continuous work he felt warranted in 1852 in asking for a patent. 

 So skeptical was the Patent Office that letters were not granted until 

 1862. In 1841 the first real fish cannery was established at East- 

 port, Me., the product being lobsters and mackerel, and by 1860 there 

 were a number of canneries on the coast, handling both fish and 

 vegetables. The first cannery in the Central States seems to have 

 been established in the early sixties in Cincinnati, closely followed 

 by one at Indianapolis. Canning was begun at San Francisco in 

 1856 and in the Alaskan waters in 1878. 



The Civil War gave the first great impetus to canning in this 

 country. That event showed the enormous advantage of having 

 canned foods and emphasized their general superiority over the dried 

 foods in palatability. The more recent extension of the industry has 

 been due largely to a better knowledge of the wholesome character 

 of canned products and the economy in their use. 



EARLY THEORIES ON PRESERVATION BY CANNING. 



From the beginning there were numerous theories explaining the 

 preservation of foods by canning. The first was that of the exclu- 

 sion of outside air. This theory was recognized in part by Appert 

 in his description of the preservative process. 



It is obvious that this new method of preserving animal and vegetable sub- 

 stances proceeds from the simple principle of applying heat in a due degree to 

 the several substances, after having deprived them as much as possible of all 

 contact with the external air. It might, on the first view of the subject, be 

 thought that a substance, either raw or previously acted upon by fire, and 

 afterwards put in hot bottles, and they completely corked, [would] be preserved 

 equally well with the application of heat in the water bath. This would be 

 in error, for all the trials I have made convince me that the absolute privation 

 of the external air (the internal air being rendered of no effect by the action of 

 the heat) and the application of heat by means of a water bath, are both 

 indispensable to the complete preservation of alimentary substances. 



Appert did not know what was in the air to cause spoilage, but did 

 recognize that it was the external and not the internal air. At this 

 time some foods and wines were being preserved by excluding the 

 air, the method being to cover the surface of the food or wine 

 with hot oil. The experimenters, following Appert, laid special 

 stress on excluding air, and when tin cans were first used care was 



