84 American Fisheries Society 



. 



lyzers with a great diversity of carriers, ranging from 

 pumice stone and kieselguhr to charcoal and sawdust." 



"By hydrogenation, oils which formerly made soaps 

 only of soft consistency, now yield the more valuable 

 hard soaps. This has led to a very rapid development 

 of the art with respect to the production of soap-making 

 fats. In particular, fish and whale oils have been made 

 use of because these oils may be completely deodorized 

 by the addition of hydrogen. . . . When hydrogenated 

 down to an iodine number of about 50, fish oil has the 

 consistency of hard tallow and the odor of fish oil is 

 wholly absent. Even the fishy taste is scarcely in evi- 

 dence. For soap-making, this product is satisfactory as 

 it complies with the test for a deodorized fish oil suitable 

 for soap-making in that the odor of the original oil is 

 not apparent when ironing laundered goods on which 

 such soaps are used." 



In the consideration of the edibility of hydrogenated 

 oils, the presence of the catalyzer in the finished product 

 must be considered. "Whale oil, containing 0.6 per cent, 

 fatty acid, yielded 0.006 per cent, ash and 0.0045 per 

 cent, nickel oxide. Such an amount of nickel presum 

 ably would not be tolerated in a product intended for 

 edible purposes." 



MENHADEN OIL. 



In the United States, menhaden oil obtained in the 

 south Atlantic waters is called "Southern" oil and is dis- 

 tinguished from "Northern" oil by its lighter color, and 

 by the fact that it contains more glycerides of higher 

 fatty acids, therefore depositing a greater quantity of 

 stearine when cooled. The oil is sold under several trade 

 names — "Prime Crude," "Brown Strained," "Light 

 Strained," "White Bleached" and "Yellow Bleached," de- 

 pending on the degree of refinement. Sometimes the 

 grades are called "A," "B," "C," and "D," the distinction 

 being based on the color, "A" grade being a very light 

 yellow, while "D" grade is the very dark brown oil. 



