UTILIZATION OF THE FISH WASTE OF THE PACIFIC OCEAN. 35 



fully, than to apply them direct to the soil. It can be taken as thor- 

 oughly well established that both the nitrogen and the phosphoric 

 acid, after performing their role in the life processes of the adult 

 animal, are eliminated. Then the high food value of these rich foods 

 is utilized, and at the same time the fertilizing elements are still 

 available for use on the growing crops. From the point of view of 

 cattle and poultry feed, the salmon scrap must be considered supe- 

 rior to the menhaden. In the first place, the acidulated scrap is 

 totally unfit for feeding purposes. Its use in that manner undoubt- 

 edly would result in disaster. And in smaller degree, the greater 

 care expended in drying the salmon scrap makes it a more desirable 

 article of food. In fact, when the nature of the raw material and 

 the sanitary condition under which it is treated, obtaining in certain 

 manufactories, are considered, it might almost be regarded as fit for 

 man's consumption. It would be interesting to learn whether the 

 oil remaining in the salmon scrap is of a more digestible nature than 

 that in the menhaden scrap. Xo experimental data is at hand in sub- 

 stantiation of such belief; but such appears plausible when it is re- 

 called that the salmon oil is light and sweet and partakes more nearly 

 of the nature of the edible oils, while that from menhaden is dark, 

 heavy, and viscous and has a disagreeable odor. 



The subject of the suitability of fish scrap for cattle and poultry 

 feed and the experiments performed relating thereto have been dis- 

 cussed in an earlier publication of this department and therefore 

 will not be repeated here. In all of the experiments, records of 

 which have come to the attention of the writer, the results have been 

 affirmative and of such a nature as to justify the further exploita- 

 tion of this food material for that purpose. The reader interested 

 in this phase of the subject is referred to Bulletin 2. United States 

 Department of Agriculture, The Menhaden Fish Fertilizer Indus- 

 try of the Atlantic Coast. 



OIL. 



The literature contains little having to do with salmon oil. The 

 amount actually produced, 286,000 gallons, is too small to give it 

 any great importance in the industries. It is rated, however, as a 

 high-grade fish oil. The price which it brings in the market, 30 

 cents a gallon, against 23 cents for menhaden oil, is sufficient evi- 

 dence of that fact. There is no reason to doubt that it is destined 

 to play a"n important part as an animal oil when the salmon-scrap 

 industry is fully developed and there is enough oil available to 

 make its study and exploitation profitable. 



In the absence of more detailed information concerning the physi- 

 cal and chemical properties of salmon oil, it must suffice to say that 

 it is merely a high-grade fish oil. The crude salmon oil is lighter 

 in color than, perhaps, the refined menhaden. Its properties, as now 



