322 Mr. Take Sone on the Magnetic Susceptibilities 



Eight sets of such observations made at various tem- 

 peratures ranging from 14° C. to 18° C. give the following- 

 values of the susceptibility of oxygen, which are all reduced 

 to the value at 20° C. 



10*. X o= 104*00, 104-48, 104*00, 104-10, 103*89, 104-12, 

 104*60, and 103*86, the mean of which is 



Xo =104* 1 xlO- 6 at20°C.. 



the mean error being +0 09 x 10~ 6 . Multiplying the density 

 of oxygen at 20° C. and 760 mm. pressure, we get as the 

 susceptibility of oxygen gas per cubic centimetre, 



yr O2 =0'138 6 x 10" 6 ±0-0001 x 10" G . 



The above result is in fair agreement with Piccard's value, 

 which seems to be the most reliable among the values of 

 the previous investigators, but as he used a commercial 

 oxygen, the error which might arise from the impurity of 

 the gas w r ould probably make the mean error of his result 

 larger than he had believed. He also determined the mass 

 of the gas by the absorption method, which is accompanied 

 by some uncertainty. In the present case the gas was 

 obtained by electrolysis and carefully purified, so that there 

 is no uncertainty about its purity. At any rate the error in 

 my case, if there is any, may arise from the determination 

 of the susceptibility. 



If the magnetism of air is due solely to that of oxygen 

 present in it, the ratio of the specific susceptibilities of air 

 and oxygen should be identical with the ratio of the mass of 

 the oxygen in air to the total mass of air, that is, the ratio 



-^ = f^ =0-2291 



must be equal to 0*2315, the difference being 0*0024. 



The difference amounts to about 1 per cent, of the total 

 value and is certainly beyond the experimental errors of the 

 measurements of the susceptibilities. The explanation for 

 this discrepancy will be given later on. 



I§ 7. Carbon dioxide. 



About ten years ago Professor K. Honda * found an 

 anomalous behaviour of tin in that its magnetic property 



* K. Honda, loc. cit. 



