TABLE OF CONTENTS. 



CHAPTER I. 



Preliminary Experiments . 



1. Color tube. 3. Jet. 3. Available color sequences. 4. The boundaries of tlie opaque region. 

 5. Ionizers and "dust" producers. Phosphorus. 6. Ignited ionizers. 7. Concentrated sul- 

 phuric acid. 8. Thermal dissociation. 9. Hot metallic surfaces. 10. Ammonic polysul- 

 phide. 11. Volatile chemicals. 12. Electrical (high potential) ionizers. 13. Perfected 

 device. 14. X-ray ionizers. 15. Persistence of nuclei. 16. Coefficient of decay. 17. Per- 

 sistence of nuclei in long tubes. 18. Persistence of X-ray nuclei in long tubes. 19. Dif- 

 ferential experiments with long tubes. 20. Ultra-violet ionizers. 



CHAPTER II. 



The Colors of the Steam Jet, as Related to the Number of Nuclei in Reaction 16 



1. Preliminary. 3. Apparatus. 3. Results of the graduation. 4. Results charted. 5. Dis- 

 cussion. 6. Color margins and distribution. 7. Effect of steam pressure. 8. Effect of air 

 temperature. 9. Corroborative method of graduation. 10. Modified color tube. 11. Results. 

 13. Discussion. 



CHAPTER III. 



Transmission of the Ionized Emanation of Phosphorus through Air in the Absence of 



an Electric Field ; ^^ 



1. Introductory. 3. Method and apparatus. 3. Results for thin tubes. 4. Results for wide 

 tubes. 5. Working hypothesis. 6. Computation for saturated emanation. 7. Case of ab- 

 sorption without decay. 8. Computation for diluted emanation. 9. Case of decay without 

 absoi'ption. 



CHAPTER IV. 



Tlie Transmission of the Ionized Exhalations of Phosphorus through Air and Other Media 



the Presence of an Electric Field -^^ 



SailSSiUU Lli mc ilJIJl^cl-l .UJAHamuiv^no vyi. J- nv^.jj. ...... ...- — "'-o-- — '■ 



in ' ^ ' -"!•.- 



Transmission through Air. 



1. Object and plan. 3. Apparatus and method. 3. Computation. 4. Data as to ageing of 

 the ionizer. 5. Effect of temperature. 6. Fall of potential in the lapse of time. 7. Insuf- 

 ficiency of the geometric equation of leakage. 8. Effect of distance between condenser plates. 

 9. Another computation. 10. Working hypothesis. 11. Electrical considerations introduced. 

 13. Constants computed. 13. Number of ions in the saturated emanation. 14. Electrolytic 

 mechanism. 



Transmission through Solid Media. 



1.5. Method. 16. Results. 17. Effect of temperature, etc. 



Ionization by other Dust Producers. 



18. Concentrated sulphuric acid. 19. Annnonic polysulphide. 



