314 Professor Arthur W. Crossley [Feb. 5, 



have been made in the past to find commercial methods for the con- 

 version of oleic acid into stearic acid, such as the action of iodine or 

 sulphuric acid or by the electric discharge (for an outline of and 

 references to these processes see Carleton Ellis, J.S.C.I., 1912, xxxi. 

 1155), but it was the work of the two French chemists, Saba tier and 

 Senderens, which directly led up to the hydrogenation of oils in 

 presence of reduced nickel or other catalyst. Sabatier and Maihle 

 (Ann. Chim. Phys., 1909 (8), xvi. 78) have shown that oleic and 

 elaidic acids, when treated with hydrogen in presence of reduced 

 nickel at 280-300°, are almost entirely transformed into stearic 

 acid ; but in -these experiments and quite generally in the application 

 of Sabatier and Senderens' reaction, substances are only used in the 

 state of vapour. Notwithstanding this and the fact tliat these authors 

 lay stress on the point that the catalyst should not be allowed to 

 become moistened with the substance under treatment (Ann. Chim. 

 Phys., 1905 (8), iv. 335), the present methods for the hardening of 

 oils must be acknowledged to be the direct outcome of the researches 

 of Sabatier and Senderens. 



The first patent dealing with the hydrogenation of oils in the 

 liquid form was taken out by Normann (Eng. Pat. 1,515, 1903), who, 

 after referring to the work of Sabatier and Senderens, states : " I 

 have found that it is easy to convert by this catalytic method un- 

 saturated fatty acids into saturated acids. This may be effected by 

 causing the vapours of fatty acid, together with hydrogen, to pass 

 over the catalytic metal, which is preferably distributed over a suit- 

 able support, such as pumice-stone. It is sufficient, however, to 

 expose the fat or the fatty acid in a liquid condition to the action of 

 hydrogen and the catalytic substance. For instance, if fine nickel 

 powder obtained by reduction in a current of hydrogen is added to 

 chemically pure oleic acid, then the latter heated over an oil bath, and 

 a strong current of hydrogen is caused to pass through it for a 

 sufficient length of time, the oleic acid may be completely converted 

 into stearic acid. The quantity of the nickel thus added and the 

 temperature are immaterial, and will only affect the duration of the 

 process. Apart from the formation of small quantities of nickel soap, 

 which may be easily decomposed by dilute mineral acids, the reaction 

 passes off without any secondary reaction taking place. The same 

 nickel may be used repeatedly. Instead of pure oleic acid com- 

 mercial fatty acids may be treated in the same manner. The same 

 method is applicable not only to free fatty acids, but also to their 

 glycerides occurring in nature, that is to say, the fats and oils. Olive 

 oil will yield a bard tallow-like mass ; linseed oil and fish oil will give 

 similar results. 



•'By the new method all kinds of unsaturated fatty acids and 

 glycerides may be easily hydrogenized. It is not necessary to employ 

 pure hydrogen for the purpose of the present invention ; commercial 

 gas mixtures containing hydrogen, such as water gas, may also be used." 



