124 



ANNUAL EEPORT SMITHSONIAN INSTITUTION, 1934 



occurring substances. Since heavy deuterium water costs, at a con- 

 servative estimate, $5 per gram, it is evident that, with a 100 per cent 

 eflSciency of recovery of its tritium content, pure tritium water, T2O, 

 would cost at least $1,000,000 a gram or water roughly 20 times the 

 cost of radium. Such are the paradoxes of modern isotope chemistry. 





■a 

 « 



(pj>y 





(hh)^jo' 



(HD) 

 JL_ 



(HD2>)^10 



^ (■DT>Xi)*/0^ 



/ Z 3 ^ S 6 



/^ixsses of tke Ions 



Figure 1. — Diagrammatic representation of an analysis by the mass spectrograph of a gas 

 sample rich in deuterium. Each peak represents the abundance of the Ion of mass 

 given along the horizontal axis of the graph. The scale for the ions H+, (HH)+, 

 (HDD)+, and (DDD)+ is multiplied by the amounts shown against each peak to 

 permit their representation on the same diagram in spite of their great rarity. The 

 analysis yields 98 atom percent D and 2 atom percent H. 



Using the same method of analysis it is possible to follow the rate 

 of reaction of one isotope of a given element with its one isotope. 

 It has been shown, for example, that H2 molecules will react with D2 

 molecules to form HD molecules at temperatures as low as that of 

 liquid air, with catalysts such as chromium oxide and nickel, which 

 are active in catalytic hydrogenation processes. These results indicate 

 that the high temperatures necessary in industrial syntheses such as 

 those of anmionia or wood alcohol are required not for the activation 

 of the hydrogen but for the activation of the molecules with which the 

 hydrogen has to react. If surfaces can be found as active toward these 

 molecules as present available surfaces are with respect to hydrogen, 



