98 



LIFE: ITS NATURE AND ORIGIN 



then concentrated, the oxidizing nitrous gases being recovered by 

 "scrubbing" in Gay-Lussac and Glover towers. The sulfur dioxide 

 was made largely from iron pyrites. This often contained arsenic 

 which, unless removed at considerable cost, contaminated the acid 

 and "poisoned" platinum catalysts, when these were used to oxi- 

 dize the S0 2 into S0 3 in the presence of air. Due in part to the 

 availability of cheap and pure sulfur brought up from our western 

 "salt domes" by the Frasch process, most sulfuric acid is now made 

 by passing a mixture of air and S0 2 over catalysts, and getting 

 concentrated acid directly. Vanadium pentoxide is largely used 

 as catalyst, since it is much cheaper than platinum to install, and 

 is not so readily "poisoned." 



*-*<* 

 # 



/Mt 



^ ox 



% 



Figure 11. CATalysis. Design of a wooden medal for Kettering. Suggested to 

 Baekeland, who did not believe cyclohexane could be manufactured. 



During World War I, C. F. Kettering and Thomas Midgley, Jr., 

 of the Research Department of General Motors, in the course of 

 their collaboration with the U. S. Bureau of Mines to produce an 

 aviation gasoline as free from "knock" as possible, made exten- 

 sive engine tests with a variety of volatile organic liquids. The 

 comparatively rare hydrocarbon cyclohexane was found to be a 

 superior airplane engine fuel, and the suggestion was made that 

 its manufacture be attempted. Dr. Leo H. Baekeland, then a 

 member of the Naval Consulting Board, regarded the project as 

 impractical and advised against it. He even promised a wooden 

 medal to Kettering and his collaborators if they could make a 

 single pint of cyclohexane. 



