538 HISTORICAL INTRODUCTION TO CHEMISTRY CH. xx 



shown that further drying prevents the calomel from vaporising 

 at 352 C. In 1902, Baker showed that pure dry hydrogen and 

 oxygen did not inflame at a red heat, nor when a silver wire 

 was melted in the gas ; when dried less perfectly, a slow 

 combustion took place, but there was no explosion even when 

 visible moisture was present in the tube. In 1907, he showed 

 that nitrous anhydride, which dissociates completely at ordinary 

 temperatures (N 2 O 3 -> NO 2 + NO), can be vaporised as a 

 mixture of N 2 O 3 and N 4 O 6 if carefully dried. In 1912 he 

 showed that longer drying raised the boiling-point of the 

 anhydride from -2 to +43 C. and that the boiling-point of 

 nitrogen peroxide was raised from +22 to +69 C. 



The experiments of Gore, Veley, Reynolds and Ramsay, 

 Lambert and others have shown that purified acids do not act 

 on commercial metals, and that purified metals are not acted on 

 by commercial acids. The conditions for interaction are the 

 same as in a battery, which consists of three essential parts, 

 namely, two electrodes and an electrolyte. Armstrong, in 1885, 

 suggested that all chemical action was reversed electrolysis^ a 

 view that is supported by the whole of Baker's work. 



