[eadie-satterly] refractive INDEX OF OXYGEN 



67 



One afternoon and evening a set of continuous readings was 

 taken starting at a pressure of about 650 pds. per sq. in. and running 

 down to atmospheric pressure. The fringes passing the cross hair 

 during each step were counted and the volume escaping into the 

 burette read. Continual adjustment of the compensating glasses 

 was necessary and in some cases the fringes were not as clear as 

 in others, no doubt it is this which causes the variation of the num- 

 bers in the last column. 



This gives a total of 4028 fringes counted and a volume of 2961.4 

 CCS. of oxygen escaped. 



The corrected spectrometer reading was 5210 A.U. 



