of Hydrogen and some other Gases. 331 





Aik (p=l atrn.). 





Calculation. 



10 h 5 m 



?.M 



., <*=12°-0C 



!., 6=20-0, 



**■,= 



:- 11-74+8-15= -3-59 cm., 



m 



,+*».: 



gm. 









C. ' 





S. 



d. 



*a= 



=0-27+8-15: 



=8-42 cm., 



amp. 





CUl. 



cm. 



m w<r 



.0-1398 gm., 



m a = 0-0048 gm 









52-70 



0-20 









10 





52-90 



0-20 



^7*7/ = 



-3-59 K_ 



:- 25-68 K, 









52-70 





N'o 



0-1398 







 10 





53-40 

 53-70 



0-30 



X a = 



3-42 K . 

 " 0-0048 ~~ 



754 K. 









64-70 



0-30 



*©-- 







10 





6500 



0-30 



_ -25-68 _ 



- 0-0146. 









6470 



0-30 



X a 



1754 





10 





65-00 



0-27 (mean) 









The values obtained in two sets of observations made at 

 a mean temperature 18° 0. are 



10 6 . Xn ,=-0'36Z and -0356, 



the mean value being 



Xa ,=- 0-360 xlO- 6 . 



The volume susceptibility at 20° C. and 760 mm. pressure is 



%iV ,= -0-00042 2 xlO- 6 . 



Taking the mean o£ the results obtained for the gas 

 prepared by the first method as the magnetic susceptibility 

 of chemically pure nitrogen gas, we have, as the specific 

 susceptibility of pure nitrogen, 



%x = -0-265 xlO-o, 



and if we consider the result for the last case as the sus- 

 ceptibility of the atmospheric nitrogen containing about 

 1*7 per cent, of inert gases, of which argon is a chief 

 constituent, we have 



Xy ,= - 0-360 xlO" 6 . 



The large discrepancy between these results can never be 

 explained as an experimental error; it must be due to the 

 magnetism of the inert gases, and we may assume for the 

 present that the result is due only to the magnetism of argon, 

 as the quantities of other gases are exceedingly small. 



Now let us calculate the magnetic susceptibility of air 

 from the susceptibilities of its constituent gases, assuming 



