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 visGera 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 (19141. 
