THE ROYAL SOCIETY OF CANADA 



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 ff.f.i. . 303, 



Check of Calibration by Means of Known Mixtures 

 Several mixtures of hydrogen and air and of helium and air were 

 made up from dry air, pure hydrogen and pure helium, in a water- 

 jacketted burette fitted with a compensation tube. The mixtures 

 were then passed into the gas tube of the interferometer in the usual 

 way and readings were made. 



The following table shows some of the results obtained: 



