1903.] 



Amounts of Krypton and Xenon in Air. 



425 



Residue of 1500 c.c. 



A 

 B 



(1) C 

 D 

 E 



2— 1—12—V 



8^13^18— I Eejceted 

 -4^ 9^14^19— • 

 -5^10^15^20 



-11^-16^-21 



-22- 



— 37 Rejected. 

 Rejected —38 Trace Kr. 



—23^28^-33 



—24^29^34—! 1—39 Strong Kr 



—25^30— ,35 1—40 Strong Kr 



26^-31—36— — - —41 Kr. and Xe. 



Residue. Residue. Residue. No residue. 



Xo. 41 was mixed with the residues, which contained much xenon,, 

 along with krypton. Xos. 38, 39, and 40 were mixed, and the frac- 

 tionation continued in a small apparatus. The gases were now 

 sparked with oxygen over soda, so as to remove traces of air ; for 

 the operations had now to be conducted with great care, and the 

 spectra of the two samples showed traces of nitrogen. After with- 

 drawal of oxygen from both sets of gas, by means of phosphorus, 

 the krypton mixture was fractionated into three portions ; 42, 

 containing much argon; 43, rich in krypton; and 44, a non- 

 volatile residue. The xenon residues, 41, were also solidified with 

 liquid air, and placed for a few seconds in connection with the vacuum 

 of the Topler pump. The gas which was pumped off was added to 

 43, and the residue to 44. The bulb was now left for a quarter of 

 an hour, so that equilibrium might be restored, and the stop-cock 

 opened a second time. A bubble or two was removed with the pump. 

 On making communication with the pump a third time, no gas escaped • 

 and this is not remarkable, for the vapour pressure of xenon is little 

 over 0*1 mm. at that temperature. It was therefore assumed that the 

 final residue was pure xenon ; and, indeed, its spectrum showed no 

 trace of the krypton lines. And it may also be taken for granted 

 that very little xenon was added to Xo. 43. The densities of Xos. 42 

 and 43 were determined ; and from the known densities of argon 

 and krypton, their relative proportions were calculated. 



The density of 42 was found to be 21*31, corresponding to the per- 

 centage composition, argon, 93*5 per cent., krypton, 6 '5 per cent. ; the 

 density of 43 was 39*43, implying a mixture of argon, 6*6 per cent.,, 

 krypton, 93*4 per cent. The volume of Xo. 42, reduced to 0° and 

 760 was 22-0 c.c; it therefore contained 1*43 c.c. of krypton; that 

 of Xo. 43 was 6*5 c.c, and it contained 6*1 c.c. of krypton. The 

 total volume of krypton was therefore 7*5 c.c, and its weight 

 0*0028 gramme; the volume of the xenon, reduced to 0° and 760 

 was 0*87 c.c, and its calculated weight, 0*0005 gramme. 



These results are reproduced in the following tabular statement : — 



Air passed through liquefier 191 '1 kilogrammes. 



Air liquefied 1T3 ,, = 5*91 p.c 



Argon obtained (11*8 litres at J & 760) 21*3 grammes. 



,, per cent, of gaseous air 0*0118 ; of liquid air, 0*1885. 



