22 BULLETIN 150, U. S. DEPARTMENT OF AGRICULTURE. 



lumps, together with a more or less finely divided and slimy mass 

 of roe, pieces of flesh, and viscera. In rendering, the fleshy and bony 

 portions withstand cooking with less tendency to disintegrate, as 

 they are composed largely of muscular tissue on a framework of bone 

 and cartilage. The roe, the milt, and the viscera are of much softer 

 structure and are readily disintegrated. If the roe has reached that 

 stage of development where the individual eggs have attained the 

 size of peas, each has an envelope which is hardened and toughened 

 by cooking or drying, and the albumen constituting the major por- 

 tion of the egg is readily coagulated by heat. Materials which 

 retain their structures under the cooking action of steam are rendered 

 easily, while those which, on the contrary, disintegrate into an 

 amorphous mass present serious difficulties. The preponderance of 

 heads and fleshy pieces in the waste from the salmon canneries is 

 a very favorable circumstance. 



The waste as it is removed from the cannery floor is fresh, with 

 but slight odor, and is practically entirely free from foreign sub- 

 stances. As most of the canneries are located in regions of compara- 

 tively cool climate, there is not a very strong tendency for the waste 

 to spoil. This is particularly true of Alaska. On Puget Sound 

 periods of warm weather of sufficient duration and severity to induce 

 rather rapid decomposition in the waste may be expected. Alto- 

 gether, the material is remarkably clean and inoffensive. And in a 

 by-products plant in which the waste is rendered as fast as produced, 

 the odors arising therefrom should be no more undesirable than those 

 already liberated from the salmon cooking in the cannery proper. 

 This odor, the odor of steamed salmon, can not be considered objec- 

 tionable from a sanitary point of view. 



OTHER SALMON-PRESERVING INDUSTRIES. 



The preservation of salmon in salt constitutes an industry of con- 

 siderable extent, though it scarcely compares with the canning in- 

 dustry in importance. It results in the production of large amounts 

 of waste, and deserves attention as a possible auxiliary source of 

 raw materials, under favorable conditions, for a possible adjacent 

 rendering plant. The extent to which this method of preserving is 

 carried on at any one station is scarcely great enough to warrant the 

 installation there of a by-products plant to render the waste. 



In Alaska, during the past season, "mild-curing" (the preserva- 

 tion by the aid of a small amount of salt combined with cold storage) 

 was prosecuted to the extent that 7,443 tierces, of 800 pounds each, 

 were prepared. 1 The greater proportion of this was packed in south- 

 east Alaska. In the States, 3,621 tierces were packed on Puget 



1 Bower and Fassett, Pacific Fisherman, 12, No. 1 (Special*. 58 ( 191 4 ) . 



