( 642 ) 



brought into E and the whole pumped to a good Aacuum. The 

 required quantity of gas can then be brought into E through i\ and 

 r^. The volume temperature and pressure of the gas in Ea shut off 

 by r^ and 1\ are then accurately measured and when i\ is opened 

 nearly the whole of this can be brought over into F. The remaining 

 portion in ^690 ^nd Ei^^ is then measured by expanding to ^^^2 oi' 

 Eb^^ and C/j is again closed so that E can be again evacuated. The 

 second gas is then brought directly into the volumenometer from 

 i\ and the volume measured in the same manner. 



When this is finished i\ is again opened and the second compo- 

 nent in E mixed Avitli the lirst in F where it stands for some 

 time. The admixture of the total quantity is completed by 

 drawing the combined gases several times backwards and forwards 

 between the two vessels. The mixture is then preserved in 7^^ and as 

 much as may be necessary is driven into Ei^ or through i\ into 

 other apparatus for measurements on the compressibility. 



(April 24, 1903). 



