TABLE OF CONTENTS. 



Chapters I-II. — Relating to "Experiments with Ionmzed Air," Smithsonian Contri- 

 butions TO Knowledge, Vol. xxix. No. 1309. 



CHAPTER I. 



P.^GE 



The Relation of Ionization to Nucleation in Air after Contact with Phosphorus i 



I Introductory. 2. Method proposed. 3. Water nuclei. 4. Comparison of the steam 

 jet and the condensation chamber. 5. Decay and absorption. 6. Apparatus. 7. 

 Manipulations. 8. Data for phosphorus ionization, q. Further data. 10. EflEect of 

 different charges in the condenser. 11. Dried emanation. 12. Wet emanation. 13. 

 Residual ionization after one hour. 14. Nucleation partially precipitated. 15. Ioni- 

 zation of dry phosphorus nuclei. 16. Inferences. 



CHAPTER II. 



The Relation of the Ionization and the Nucleation Associated with Water Nuclei, 



Produced in Air 17 



loniz ation Produced by Shaking Solutions. 



I. Introduction. 2. Apparatus. 3. Results. 



Efficiency of Nuclei-Producing Jets. 



4. Powerful methods of comminution. 5. Results. 



The Ionization of Water Nuclei. 



6. Introductory. 7. Apparatus. 8. Results. Initial charges. 9. Comparison with 

 coronas. 10. Evanescence of the charges of water nuclei. 11. Results with an Elliott 

 electrometer. 12. Further data. 13. Jets self-shattering or impinging on water. 14. 

 Summary of the relative degree of ionization and nucleation. i 5. Spontaneous time loss 

 of nuclei. r6. Effect of condonsalicm on ionization. 17. I'^ffeclive condenser length. 



Summary and Inferences. 



18. Working hypothesis, ig. Charge and conduction. 20. Comparison of phosphorus 

 and water nuclei. 



Chapters III-VII. — Relating to "Structure of the Nucleus," Smithsonian Contri- 

 butions TO Knowledge, No. 137.3. 



CHAPTER III. 



Preliminary Survey of the Apertures of Coronas in Relation to the Number of Nuclei 



and their Sizes 39 



I. Introductory. 2. Apparatus and preliminary results. 3. Diameter of cloud particle. 

 4. Nucleation. 5. Cause of periodicity. 6. Effect of temperature. 7. Pressure decre- 

 ment. 8. Summary. 9. Plate-glass apparatus. 



xi 



