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XXIX. On the Magnetic Susceptibilities of Hydrogen and j 

 some other Gases. By Take Soke *. 



Index to Sections. 



1. Introduction. 



2. Method of measurement. 



3. Apparatus for measurement. 



(rt) Magnetic balance. 



(b) Compressor and measuring tube. 



4. Procedure for measurements. 



(a) Adjustment of the measuring' tube. 

 {b) Determination of the mass. 



(c) Method of tilling- the measuring tube with gas. 



(d) Electromagnet. 



(e) Method of experiments. 



5. Air. 



6. Oxygen. 



7. Carbon dioxide. 



8. Nitrogen. 



9. Hydrogen. 



(a) Preparation of pure hydrogen gas. 



(b) Filling the measuring tube with the gas. 



(c) Results of magnetic measurement. 



( d) Purity of the hydrogen gas. 

 10. Concluding remarks. 



§ 1. Introduction. 



IN the electron theory of magnetism, it is assumed that 

 the magnetism is due to electrons revolving about the 

 positive nucleus in the atom ; and hence the electronic 

 structure of the atom lias a very important bearing on its 

 magnetic properties. The models of the atoms or molecules 

 hitherto proposed are so constructed as to explain only the 

 phenomena of light ; but the question whether the nature 

 of atomic or molecular magnetism, due to the system of the 

 revolving electrons, agrees with the results of observation 

 or not, is in most cases not touched at all. For example, 

 Bohr's model t of hydrogen molecules explains very satis- 

 factorily the light dispersion of hydrogen ; but its magnetic 

 polarity is paramagnetic in contradiction to the observed 

 fact that hydrogen gas is diamagnetic. A correct theory of 

 the constitution of the atoms or molecules must, however, 

 not only explain the phenomena of light, but also their 

 magnetism. In this respect, a knowledge of the magnetic 

 susceptibility of various gases, especially those of hydrogen 



* Communicated by the Author. 



t N. Bohr, Phil. Mag. xxvi. p. 857 (1913); P. Debye, Site, d. math.- 

 phys. Klas. d. Akad. d. Wissensch. Munchen, p. 1 (1915). 



Phil. Mag. S. 6. Vol. 39. No. 231. March 1920. X 



