228 Prof. W. Ramsay and Mr. M. W. Travers. 



Oxygen.— Oxygen/hydrogen . . . 1*9512 Mean > # 1#9512 



1*9512 



Oxygen/nitrogen. . . . O9090 



0-9122 „ . . 0-9105 



0- 9103 



Nitrogen. — Nitrogen/air 1*0153 



10171 „ 1*0166 



1- 0174 



Nitrogen /hydrogen . . 2*1487 9 UW 



2*1487 " " 



Nitrogen /oxygen. . . . 1*1001 



1-0962 „ .. 1*0983 



1*0986 



To these numbers those for argon must be added. The gas was pre- 

 pared in the usual manner from air; and before admitting it into the 

 experimental tube it was sparked with oxygen in presence of caustic 

 soda for two days. The oxygen was removed with phosphorus, and the 

 argon, on its way into the experimental tube, passed over phosphorus 

 pentoxide ; a Plucker's tube was sealed to the tube through which it 

 entered, so that its spectrum might be observed. It contained no 

 visible trace of either hydrogen or nitrogen. 



Argon. — Ai'gon/air 0*9596 



0-9596 Mean . . 0*9596 



0- 9598 



Argon /oxygen 1-0350 



1- 0348 „ . . 1*0362 

 10381 



Argon/nitrogen 0'9412 0-Q4/lfi 



0-9419 " UyMb 



Placing air in each case equal to unity, and calculating the refrac- 

 tivities of the other gases, we obtain the following table : — 



Befr activities of Gases, Air equal to Unity. 



Through 





Directly 



r 



A 









compared. 



Oxygen. 



Nitrogen. 



Hydrogen. 



Argon. 



Hydrogen .... 



0-4733 



0-4737 



0*4727 









0-9243 





09247 



0-9237 



0-9261 



Nitrogen .... 



10163 



1-0155 





10170 



1*0191 





0-9596 



0-9577 



0*9572 







Carbon dioxide 





1-5316 









