[ 795 ] J 



LXXVI. The Molecular and some other Constants of the 

 Inactive Gases. By G. Rudorf, Ph.D., B.Sc* 



Part 1. 



ff^HE monatomic gases are of particular interest from the 

 J_ standpoint of the kinetic theory, and the present paper 

 has for its object the calculation of some of the molecular 

 constants in various ways with a view to seeing how far the 

 values thus obtained agree among themselves. It may be 

 stated at the outset that the result is disappointing. 



A. Molecular Velocities. 

 The kinetic theory of gases gives us the equations 



P=IPG^ (I.) 



and „ / x 



Q= vt G ' C 11 -) 



where G is the velocity calculated from the mean kinetic 

 energy (Clausius) and XI the mean velocity according to 

 Maxwell, p the pressure, and p the density. 

 For a pressure of 1 atm., 



j) = 76 x 981 x 13-595 dynes/cm 2 , 

 and G= /3-011 xT0 6 # 



To calculate G and O then we require to know only the 

 density p. 



Helium. — Ramsay and Travers (Proc. Roy. Soc. lxii. 

 p. 316 (1898)) give the value 1*98 for the density com- 

 pared with oxygen (16). Taking the weight of 1 litre of 

 oxygen as 1*1296 g.f, a value used by them in a later paper 

 (y. infra), we get for the weight of 1 litre He 0*1769 g., 

 and hence for the density 0*0001769. As the experimental 

 data are not given in the paper, wo must be content with this 

 figure. The value 1'98 for the density compared with oxygen 

 has since been amply confirmed, e. g. Olszewski, Kamerlingh 

 Onnes, Schierloh, &c. 



Neon. — From the experimental data published by Ramsay 

 and Travers (Phil. Trans, exevii. p. 47 (1901)), the density 

 works out top = 0*00089. 



\_JSote. Owing to an oversight, the volume of the bulb 

 used in determining the density was given as 32*038 c.c. 

 Sir Wm. Ramsay has kindly informed me that the correct 

 value should be 32*697 c.c] 



* Communicated by Sir W. Ramsay, K.C.B., F.R.S. 

 t All figures relating- to densities are referred to 0° C. aud 760 mm. 

 pressure. 



