145 



From tlie foregoing experiments tlie follo\Ying eonclusinns appear jns- 

 tifiable. First, nascent li.vflrogen <il)tainecl from varying sonrces and in con- 

 tact with different substances has abnut the same reducing power. And, 

 second, gaseous liydrogen in contact witli inetals used tO' make nascent 

 hydrogen is not made more active by that contact. If tliese conchisions 

 are justifiable tlie argument upon which the "contact" explanation is 

 based becomes greatly weakened. And it becomes still weaker when the 

 first part of the work of Traube. described above, is considered. For If 

 contact with palladium is the only cause of the activity of nascent hydro- 

 gen there is i.o reason wh.y the same substance should not have formed at 

 the two poles. It remains to show that the activity of absorbed hydrogen is 

 not due to contact action. 



INIuch work has been done in investigating tlie phenomena of absorp- 

 tion of gases by metals. From the volume of giis absorbed by different 

 metals, as platinum, silver and nickel, Sieverts (Zeit. fur Phys. Cheni. LX, 

 129 and LXVIII, 115) concluded that the absorbed element was in the 

 atomic state. Richardson (Phil. Mag. VI^ 20/1 and VIII. 1), in his studies 

 on the diffusion of gases through metals came to the same conclusion, say- 

 ing "This result can be explained by supposing that the hydrogen is dis- 

 sociated and that the dissociated atoms pass freely through the platinum." 

 Gladstone and Tl-ibe in their woik on "The Action of Substances on Nas- 

 cent and Occluded Hydrogen" (('. S. Journ. 1S79. 179, Trans.) say "Among 

 other I'esults of this investigation we may >*laiin to have established still 

 more fully the close likeness of character and thei'efore of condition be- 

 tween hydrogen usually denominated nascent and hydrogen occluded by 

 metals." Also Bain in his work on the absorption of hydrogen by carbon 

 (Zeit. fur Phys. Chem. LXVIII. 171) concludes that the absorbed hydro- 

 gen is in the atomic state. If these conclusions are .iustified the activity of 

 absorbed hydrogen need not be longer considered as due to "contact" 

 action. But if it still be found that contact does modify tlie activity of ele- 

 ments is it not a condition of chemical activity or a means of altering the 

 velocity of a chemica.l change rather than an explanation? Does not the 

 question remain, "Why, and in what manner they do so? Manganese diox- 

 ide accelerates the decomposition of potassium chlorate, imt this fact does 

 not throw any light on the mechanism of the reaction nor does it explain 

 why the oxygen at the instant of separation is a better oxidizing agent 

 than ordinary oxygen at the same temperature. Heat is a necessary condi- 



10—33213 



