1915] on Science and Industrial Problems 323 



very serious nature, as the hardened fat could be mixed with a suitable 

 quantity of another fat, which would give the desired quaUtv to the 

 resultino^ soap. 



Hardened fish oil is odourless and gives a good soap, but unless 

 the iodine value of the oil has been lowered during hjdrogenation to 

 50 or less, then, on ironing materials washed with such soap, the 

 odour of fish oil again becomes noticeable. 



Hardened oils seem likely to be used largely in the future for 

 lubricating purposes, and as foodstuffs. Even at the present time 

 hardened cotton seed oil, a substance resembling lard, is used edibly, 

 and a great number of physiological experiments carried out on the 

 edible properties of hardened whale oil (Offerdahl, Ber. deutsch. 

 Pharm. Ges., 1913, xxiii. 558) have proved it to be easily digested. 



One point, however, Avill require very careful consideration in this 

 respect, namely, that, as mentioned in the patent, an oil hardened by 

 a process including nickel as catalyst always contains small amounts 

 of nickel, as nickel soap, i.e. the nickel salts of the acids contained in 

 the original oil. Offerdahl has shown that the average amount of 

 nickel in hardened whale oil is from 0*5-2 milligrams per kilo., 

 whilst the most found was 4 milligrams per kilo. Despite the facts 

 that 99*8 per cent of nickel taken is eliminated from the system, and 

 that Nermann and Htigel (Halbmonatsschrif t fiir Margarine-industrie, 

 1913, vi. No. 17) have shown that this amount of nickel is very much 

 less than that contained in many foodstuffs prepared in nickel vessels, 

 which have had no injurious effects on those who have eaten them, 

 the matter is one which wdll require detailed attention, and hence 

 into this industrial problem is drawn still another research worker, 

 namely, the physiologist, and Ave may leave him to work out his 

 experiments while passing on to consider another phase of research as 

 applied to industrial problems. 



The investigation of the process of fat burdening provides an 

 instance of a research in which the problem to be solved is recognized 

 from the start ; it is therefore systematically attacked and conquered. 

 The question to be answered is simply — What are the conditions 

 under which it is possible to change an oil into a solid fat, by the 

 addition of the necessary number of atoms of hydrogen to convert. the 

 glycerides of unsaturated acids into the glycerides of saturated acids ? 

 There are, however, other types of problems which come under the 

 notice of the research chemist, where, for example, though the ultimate 

 aim is a perfectly definite one, the means of attaining the desired end 

 are not foreseen, and it is only by the systematic scientific investiga- 

 tion of thousands of chemical derivatives in the laboratory that the 

 end is finally achieved. 



The domain of organic chemistry proper or the chemistry of the 

 compounds of the element carbon may be called upon to provide an 

 example. The organic research chemist is frequently alluded to with 

 perhaps a tinge of scorn as a " compound maker," by which epithet 



