9 8 6 A P P E N D I X J the two atoms or molecules. There might then be a change in the structure of these spectral lines that would depend, in a way, on the combinations of atoms. Experiments on this topic have been conducted at high pressure! Dr. Damianovich: Experiments have been conducted at a pressure of 40 millimeters with a mixture of H and Hg. In this case, the potential of the inelastic collision reaches 20 volts, according to Dejardin. Dr. Einstein: And is the potential for ionization of He affected by the presence of Hg? Dr. Damianovich: Certain lines disappear completely at a pressure of 0.003. There is an influence that we can conclude comes from active He, formed by molecules owing their ex- istence to coplanar atoms and crossed atoms. Dr. Einstein: I don’t understand how certain lines can disappear without having the en- tire spectrum disappear it seems impossible to me that, if there is a series, only certain lines disappear. It’s impossible to explain these things using current theories. I don’t think a fine structure can be found because one would need to believe in the existence of a class of very unstable molecules, and also because the influence of the other atom or molecule would be very weak. Dr. Damianovich: Can we imagine the following: that, in the case of a mixture of Cl and He, one might find, in addition to the lines belonging to each element, pre-combination lines due to the chemical excitation of the atoms or molecules of one element by the pres- ence of those of the other before they combine, that is, lines produced by the mutual pres- ence of both elements? Dr. Einstein: I’m not so sure about that, but I can’t swear it’s impossible. Dr. Damianovich: If one atom influences another through induction, could a modifica- tion in the eccentricity of the ellipses be produced through the effect of the chemical field and could one see the effect of chlorine, for example, in the fine structure of the lines? Dr. Einstein: One could see only a broadening. Dr. Damianovich: What about the splitting of hydrogen doublets that has confirmed the Theory of Relativity? Dr. Einstein: That phenomenon is very difficult to observe in helium. Dr. Damianovich: Can the dissociation of a hydrogen molecule into atoms produce a chemical field that influences the broadening of the lines? Dr. Einstein: I think an effect can be produced, but not a clear effect that strikes me as impossible. It’s reasonable to think that the action of an atom or molecule can change the position of a line, but since all relative positions are possible from one side and the other, we do not have, I repeat, a clearly observable effect. Dr. Damianovich: Does Dr. Einstein think that the possible combination of helium and chlorine can be observed spectroscopically, with a large dispersion? Dr. Einstein: If a combination exists, I think there will be a dislocation of molecules, but the effect will be very small for observational purposes. The experiment can be tried—I won’t swear that it’s impossible to find the effect—but if it exists, it will be very small. It will be very difficult to observe.