704 MARINE PRODUCTS OF COMMERCE 



Table 154. Oils of Common Porpoise {"Pliocaena communis") Analytical 



Constants. 



C22 



Body 13.6 3.5* 12.1 4.7 4.7 (—2H) 27.2 (-2H) 16.7 (—2.8H) 10.5 (-4. 8H) 7.0 (— 4.9H) 



Head 20.8 4.1 15.8 7.5 0.2 4.6 (-2H) 20.8 (— 2H) 15.2 (— 2.6H) 9.4 (— 4.5H) 1.6 (— 4.7H) 



Jaw 



Liver 4.6 9.0 1.2 0.1 (—2n) 16.5 (—2H) 27.0 (-2.4H) 31.0 (—3.3H) 10.6 (—5.4H) 



* Traces of Lauroleic Acid, 

 [columns for foetus omitted]. 



Source: Lovern. J. A., "Fat Metabolism in Fishes and Cetaceans. III. Selective Formation of Fat 

 Deposits," Biochem. J., 28, 394-401 (1934). 



In refining, the oil is heated in tanks by means of steam coils until all moisture 

 is expelled. After heating from 6 to 10 hours the oil is allowed to settle and partly 

 cool, during which process the solid impurities settle out. The purified oil is then 

 drawn from the top of the tank into barrels and casks. 



The oil is then chilled. In cold weather this is done by placing the barrels out 

 of doors. At other times this is accomplished by artificial refrigeration. The con- 

 gealed mass is usually dumped on wooden strainers. After the liquid oil has 

 drained off, the residue is placed in canvas or hemp bags, holding from 2 to 4 

 gallons each, and subjected to great pressure. The first oil from the press con- 

 geals at 36 to 40° F (2.2 to 4.4° C), and is called "winter whale oil." The foots 

 or stearin that remain in the bags average Mo the original bulk of the oil, and are 

 usually white. 



Some oil is bleached by treatment with caustic soda or soda ash, or by expo- 

 sure in shallow vats to the action of sunlight, or by filtration through fuller's earth. 



Composition and FropeHies. Whale oil resembles the slow-drying fish and fish- 

 liver oils in many respects. The highly unsaturated fatty acids consist chiefly of 

 clupanodonic acid, which is also found in fish and fish-liver oils, but there is a 

 greater amount (30-45 per cent) of unsaturated C^^ acids. 



The iodine value of a given specimen of oil depends to a large extent upon the 

 amount of "stearin" left in the oil since the "stearin" consists chiefly of palmitin, 

 a saturated fatty acid. The deposited stearin has an iodine value of about 40. The 

 amount of unsaponifiable matter in commercial whale oil varies from about 0.65 

 per cent to 3.72 per cent. As a rule the lower the quality of the oil, the higher the 

 percentage of unsaponifiable matter. The characteristics of a number of samples 

 of whale oil are presented in Table 155 (p. 705). 



Use. Prior to the discovery of the process of obtaining kerosene by the distilla- 

 tion of petroleum, whale oil was extensively burned for illumination purposes. 

 Today very little is burned as many other superior illuminants have been discov- 



