White. — Marine Animal Oils 83 



cinating problem has been that of the conversion of oleic 

 acid or olein into stearic acid or the corresponding glyce- 

 ride." 1 Since fish oils contain large amounts of glycerides 

 of unsaturated acids, under proper conditions they should 

 add hydrogen directly, just as they take up bromine and 

 iodine. Hydrogen is very active in the presence of finely 

 divided nickel heated to a suitable temperature, and such 

 carefully prepared nickel will hasten the reduction of 

 any reducible substance. 



Catalyzers are those substances which change the 

 rate of a chemical reaction without being noticeably af- 

 fected at the end of the reaction. "With a powerful cata- 

 lyzer the hydrogenation of oils becomes a rapid, simple 

 procedure; almost, as it sometimes seems, independent 

 of the hydrogenating apparatus." 



"Catalyzers recognized as useful for the purpose are 

 nickel and palladium, although platinum, copper, iron 

 and other metals have been used to a great extent. . . . 

 As nickel is probably the most important of these cata- 

 lyzers, in view of its efficiency and relatively low cost, 

 it will be first considered. The preparation of an effec- 

 tive nickel catalyzer requires considerable care. The ox- 

 ide or hydrate of nickel is first obtained by reduction of 

 nickel nitrate, or precipitation of nickel hydrate from, 

 say, a nickel sulphate solution by the addition of an al- 

 kali. Obtained in this or any other suitable manner, the 

 next step is the reduction to metallic nickel. For this 

 purpose the nickel is placed in a receptacle which may 

 be heated controllably, and hydrogen gas is passed over 

 the mass at a temperature ranging from 250° to 500° C. 

 or so, until water is no longer evolved." Such a catalyzer 

 is very sensitive to outside influences, and is poisoned by 

 certain gases, loses its activity if exposed to the air, etc. 

 "Catalyzer made from the oxide without supporting ma- 

 terial, weight for weight, is hardly as efficient as when 

 the active surface is increased by the use of a carrier. 

 Hence we find many proposals for the production of cata- 



"The quotations referring to the hydrogenation of oils are 

 taken from the article of C. Ellis, Journal of Industrial and 

 Engineering Chemistry, Vol. 5, p. 95 (1913). 



