Distillation of Liquid Air 



523 



Fig. 3.— Relation between Logarithms of Ratios of Oxygen and N.trogen in Gas 



and Liquid phases. 



3SU 



300 













I— 





/ 































/ 







200 

 150 

 100 













/ 







































50 





/ 



/ 













Log (®\ liquid + log 100. 



250 



350 



The most probable relation, therefore, between the corre- 

 sponding ratios throughout the distillation is 



/= -2097 x^ 06737 , 



where /=100x ratio in vapour, 

 and r= 100 x ratio in liquid. 



The following series of calculated and observed ratios 

 shows the accuracy of the above equation (see table on 

 p. 524). 



As regards the boiling-points of oxygen and nitrogen, the 

 values given by previous experimenters differ to some extent 

 from those given above, but they have not all been compared 

 at the same pressure. Of the boiling-points of oxygen, the 

 two latest are by Olszewski *, in his comparison of hydrogen 



* ' Nature/ liv. p. 377. 

 2 2 



4oa 



