620 Prof. A. Battelli and Mr. L. Maori 



on 



and two similar equations for V and W. The resulting law 

 is found to be 



/=A*-M(«-U) 2 +(t;-V) 2 +(«.-w) 2 ] # m m (47 ) 



The case of a mass- velocity of rotation may be treated in the 

 same way. 



§ 39. We have so far dealt only with the case in which 

 the energy is supposed to remain constant throughout the 

 motion. Besides the energy there are no quantities which 

 are known to remain constant throughout the motion except the 

 six mass- velocities of rotation and translation, and, of course, 

 the total number of molecules in the gas. For the pur- 

 poses of the Kinetic Theory, we may suppose these mass- 

 velocities to each be zero. The solution is then given by 

 equation (45). 



On the other hand, the values obtained for the ratio of 

 the specific heats show that this solution does not accord with 

 the facts of nature. This may be for either of two reasons. 



It may be that the number of constant quantities is greater 

 than we have supposed, and that the knowledge of some now 

 unknown constant would alter our result, just as § 38 a 

 knowledge of the mass-velocity altered the result previously 

 obtained. As I have suggested elsewhere, the uniformity of 

 the experimental results obtained from different samples of 

 gas supplies an argument of overwhelming strength against 

 this supposition*. 



Or it may be that the number of constant quantities is less 

 than we have supposed, through the energy of the gas not- 

 remaining constant, a possibility which provides an escape 

 from the difficulties in question. 



LXV. On Oscillatory Discharges. 

 By A. Battelli and L. Magri f . 



i 



[Plate XV.] 



Part II. J 



The Arrangement and General Course of Experiments. 



30. T)EFORE reporting the results of experiments, we 

 X) wish to describe the whole arrangement of the 

 apparatus. 



* " The Condition necessary for Equipaitition of Energy," Phil. Mag - . 

 [6] iv. p. 585, §§ 14-17. 

 t Communicated by the Authors. 

 X Part I., this -volume, ante, pp. 1-34. 



