222 



Theory of a Non-Conservative Gas 



VALUES OF n + 3. 



[CH. X 



DISCUSSION OF RESULTS. 



267. If the experimental values were entirely trustworthy, and if our 

 theory had taken a complete account of the physical conditions, the values 

 obtained for n by all the three methods ought to be the same, and these 

 values ought to be exact integers in every case. 



-* 



Approximately this is so, although the divergencies from the values 

 indicated by theory are sufficiently marked to be noticeable. Undoubtedly 

 this is partly due to the inaccuracies of experiment.. For instance in the 

 case of oxygen the values of n + 3 calculated from the observed value of 

 C v and Cp are each 5'08, so that the discrepancy between this value and the 

 value 4r98 obtained by calculation from direct observations of 7 cannot be 

 laid to the charge of the Kinetic Theory, but must be attributed to 

 imperfections of observation. It is, in general, very much easier to obtain 

 good experimental values of 7 from observations on the velocity of sound, 

 than by finding G v and C p separately, so that the values of n + 3 in the first 

 column of the table ought to be given more weight than those in the 

 other columns. 



We shall find it convenient to discuss first the meaning of the values 

 found for n on the supposition that they are exact integers. 



