On the Magnetic Susceptibility of Liquid Oxygen. 325 



VI. With the Glass Boll No. 4. 



Volume of ball at temperature of liquid oxygen = 0'585S c.c. 

 Magnetic susceptibility of ball = T23 x 10~ 6 . 



Mean value of susceptibility of liquid oxygen as determined with 

 glass ball No. 4 = 320 x lO" 6 . 



The absolute susceptibility is derived from the apparent suscepti- 

 bility by adding or subtracting the susceptibility of the ball used 

 according as it is paramagnetic or diamagnetic. 



In the case of the copper ball, owing probably to traces of iron, the 

 paramagnetic susceptibility is rather large and varies with the field. 

 The proper additive correction was obtained by drawing a curve 

 and setting off the observed values of the copper ball susceptibility 

 as ordinates corresponding to the proper field strengths. 



The mean value from all the six sets of observations comprising 

 thirty-six determinations with the silver, copper, bismuth, and four 

 glass balls is to give a value of 324 x 10~ 6 as the mean co-efficient of 

 magnetic susceptibility of liquid oxygen. From the relation 

 fji=l+4:7rk, the magnetic permeability can be deduced, and if 

 k = 324 x 10~ 6 we have p = 1*0041, as the value of the permeability 

 of liquid oxygen. 



The value of fi we gave (see ' Proc. Koy. Soc.,' vol. 60, p. 292) 

 as the result of our former experiments by a totally different method 

 was fi = 1-00287, or nearly, 1-003. 



Hence these two methods agree in giving values of the magnetic 

 permeability of liquid oxygen differing only by about one part in a 

 thousand. 



The results of the present work must, however, be taken as giving 

 a much more probable value of the magnetic susceptibility. 



On examining the above results it will be seen that there is a 



