('«*»#') 
Mean of all observations 1.448, whence it follows that 
Z6i°.oK. = 284-2.10-6. 
Finally for finding the specific susceptibility * the density of 
oxygen was found from the formula 1 ) 
q = 1.2489 — 0.00481 (T — 68). 
From table II we obtain 
K» o°.i K .= 275,2.10-6 
^?i°.35K.= 382,8.10-6 
K6i°. 9jL =z 359,0.10-6. 
Table III gives y\/T for each of the temperatures and for each 
of the scries. 
Series with the first apparatus 
Series with the improved apparatus 
yyT.W 
71 35' 
63 9 
There is no systematic change to be noticed in the product yft/T; 
the greatest deviation from the mean is 1% with the first apparatus, 
and only l / 4 ®/ 0 with the second; moreover the deviations in the two 
series at corresponding temperatures are in opposite directions. Hence 
within the limits of accuracy of the observations the specific suscep¬ 
tibility can be represented by the formula 
*=”“. 10 -.. 
* i/r 
In the comparative measurements which we shall describe in the 
sequel we shall find the same law, at least as far as its form is 
regarded. For the discussion of this point we refer to $ 5. 
The differences between the various values of the ratio — are 
greater than we should be led to expect from the accuracy obtained 
i) Baly and Donnan. J. Chem. Soc. 81 (1902) p. 907. 
