CONTENTS. 



Chapter I. — The Transpiration of Air through a Partition of Water. 



PAGE. 



r. Molecular transpiration of a gas i 



2. Apparatus. Fig. i i 



3. Barometer i 



4. Equations. Manipulation. Fig. 2 2 



5. Data. Table i 2 



6. Conditions of flow 3 



7. Coefficients of transpiration 4 



8. Values of the coefficients 5 



9. Conclusion 6 



Chapter II. — The Transpiration of the Systems Air-Air, Hydrogen- 

 Hydrogen, Air-Hydrogen, Hydrogen-Air, etc., through Water. 



10. Introductory. Apparatus. Figs. 3 and 4 7 



11. Imprisoned hydrogen diffusing into free air. Preliminary data. Fig. 5, 



table 2 8 



12. Continued. Coefficients depending upon water heads only 10 



13. Continued. Apparent frictional resistance per molecule. Virtual viscosity. 11 



14. Continued. Transpiration depending upon barometric pressure 12 



15. Continued. Influx of air into the imprisoned hydrogen 13 



16. Continued. Coefficients depending on diffusion gradients. Transpiration.. 13 



17. Continued. Flotation 14 



18. Continued. Potential energy of the gas mixture 17 



19. Transpiration of air into air through water. Fig. 6; table 3 18 



20. Transpiration of hydrogen into hydrogen through water. Fig. 7; table 4. . . 22 



21. Transpirationof imprisoned air into hydrogen through water. Fig. 8; tables. 25 



22. Transpiration of oxygen into hydrogen through water. Fig. 9; table 6 28 



23. Transpiration of hydrogen into air through water. Fig. 10; table 7 31 



24. Correction for density of the glass. Table 8 32 



25. Summary. Relatively slow diffusion of mixed gases. Tables 9 and 10 33 



Chapter III.— Hydrostatic Methods for the Absolute Electrometry 



OF High Potentials. 



I. Hydrometer Methods. 



26. Introduction 39 



27. Absolute electrometer. Figs. 11 a, ii b, 12, 13 39 



28. Equations for the tubular float 42 



29. Constants of the tubular float. Fig. 14 43 



30. Constants of the conical float (capsule) 44 



31. Experiments with the tubular float. Table 11 45 



II. Absolute Electrometry by Aid of the Cartesian Diver. 



32. Introductory 46 



33. Apparatus. Fig. 15 47 



34. Equations. Table 12 48 



35. Measurements. Tables 13, 14 50 



Chapter IV. — The Diffusion of Gases through Solutions and 



Other Liquids. 



36. Purpose 55 



37. Apparatus. Fig. 16; table 15 55 



38. Equations 57 



39. Diffusion of air into air through water. Fig. 17; table 16 58 



40. The same, continued. Fig. 18; table 17 61 



41. Diffusion of air into air through water; further experiments. Figs. I9A,B,C, 



20; tables 18, 19, 20, 21, 22 62 



V 



