+----------------------+------+------+------+-----------------+ | Gas. | V+. | V-. | V. | Observer. | +----------------------+------+------+------+-----------------+ | Air | .. | .. | 1.6 | Rutherford | | Air (dry) | 1.36 | 1.87 | .. | Zeleny | | " | 1.60 | 1.70 | .. | Langevin | | " | 1.39 | 1.78 | .. | Phillips | | " | 1.54 | 1.78 | .. | Wellisch | | Air (moist) | 1.37 | 1.81 | .. | Zeleny | | Oxygen (dry) | 1.36 | 1.80 | .. | " | | Oxygen (moist) | 1.29 | 1.52 | .. | " | | Carbonic acid (dry) | 0.76 | 0.81 | .. | " | | " | 0.86 | 0.90 | .. | Langevin | | " | 0.81 | 0.85 | .. | Wellisch | | Carbonic acid (moist)| 0.82 | 0.75 | .. | Zeleny | | Hydrogen (dry) | 6.70 | 7.95 | .. | " | | Nitrogen | .. | .. | 1.6 | Rutherford | | Sulphur dioxide | 0.44 | 0.41 | .. | Wellisch | | Hydrochloric acid | .. | .. | 1.27 | Rutherford | | Chlorine | .. | .. | 1.0 | " | | Helium (dry) | 5.09 | 6.31 | .. | Franck and Pohl | | Carbon monoxide | 1.10 | 1.14 | .. | Wellisch | | Nitrous oxide | 0.82 | 0.90 | .. | " | | Ammonia | 0.74 | 0.80 | .. | " | | Aldehyde | 0.31 | 0.30 | .. | " | | Ethyl alcohol | 0.34 | 0.27 | .. | " | | Acetone | 0.31 | 0.29 | .. | " | | Ethyl chloride | 0.33 | 0.31 | .. | " | | Pentane | 0.36 | 0.35 | .. | " | | Methyl acetate | 0.33 | 0.36 | .. | " | | Ethyl formate | 0.30 | 0.31 | .. | " | | Ethyl ether | 0.29 | 0.31 | .. | " | | Ethyl acetate | 0.31 | 0.28 | .. | " | | Methyl bromide | 0.29 | 0.28 | .. | " | | Methyl iodide | 0.21 | 0.22 | .. | " | | Carbon tetrachloride | 0.30 | 0.31 | .. | " | | Ethyl iodide | 0.17 | 0.16 | .. | " | +----------------------+------+------+------+-----------------+ _Ions produced by Ultra-Violet Light._ Air 1.4 Rutherford Hydrogen 3.9 Rutherford Carbonic acid 0.78 Rutherford _Ions in Gases sucked from Flames._ Velocities varying from .04 to .23 McClelland _Ions in Flames containing Salts._