Institute for Theoretical Physics
July 12, 1926
Dear Dr. Noyes:
We were very glad to hear from you, and to know that you are getting along well
this summer. The news regarding people at the Institute was most welcome, too. I had
worried a little about the draft I sent you, for a accidentally ported it without
registering it, but it arrived safely.
I appreciate very much all of the work you have done on my Debye-Hüchel paper.
Your changes help the paper very much. I have carefully revised Page II, for it seemed
not to be clear even to me; I think the new version, enclosed in this letter, is much
better. In addition I feel it desirable to make the following changes:
1. crossed out
2. To replace B by Bo on all pages before P. 11
Also once each in Tables I and II,
3. Leave B as written on P. 14, but write instead of the last sentence
“In Equations 21, 22 and 23 B2is equal to 4πe2/KhT Σ(niZi2);
for in the first two no differentiation is made between √Σ(NaZi2) and
√Σ(NiZi2), and in the last equation √Σ(NaZi2) has been replaced by √Σ(NiZi2) by introducing
the correction factor S.
I hope that my explanation of the use of an averaged value of √Σ(NaZi2), independent
of r, will be clear to you. It is true that the arguments I used here are very complicated
and not too straightforward, but I think the second correction factor is really required,
and is of approximately the form I have given it. In an earlier draft of the paper
I gave the methods by which I obtained the factor ½, and showed it to not depend on
the concentration, but I found this to be only confusing, on account of its length
and complexity. If you still have this earlier draft, you might re-read this part
of it (especially the footnote regarding the independence of y on r) and incorporate
part of it, perhaps: I would like not to have the present P. 11 changed except by
If Prescott prepared any pure ZrC, even in powder form, think it would be worthwhile
to try to determine its crystal structure; for it might be of importance in regard
to the theory of tetrahedral-type crystals, developed by Grimm and Sommerfeld (you
received a reprint of this, unless it went astray). Crystal interpretation is difficult:
I am hoping to be able to do something on it soon. I have talked with Fajaus, and
also with Knorr, who has some interesting cases of non-polar compounds- metallo-organic
ones. I think it might be worth while to prepare a review of the evidence regarding
the dynamic model of the non-polar bond. I feel that Grimm and Sommerfeld’s theory,
somewhat expounded, may get support from many crystal-structures; Huggins work is
important in this connection; his only difficulty being that he wanted al crystals
to be of this type. In this regard, have you thought it worth while to buy crystal
models here? If so, I think perhaps Selmayr should start pretty soon and make them
during the winter semester, while I am here, for I’d like to have some of them made
in a special way. They seem to me to be worth having.
Hansfeld, who is a physical chemist as well as a physicist, is going to stay in America
at Johns Hopkins. Professor Sommerfeld was sorry to lose him.
We went to Zurich June 22-26 for a congress on magnetism, called by Debye. Professor
Sommerfeld presented my work on the influence of a magnetic field on the dielectric
constant of HCl; later W. Pauli Jr. showed me that probably the effect definitely
predicted by the old quantum theory would not be predicted by the new quantum mechanics.
The fact that Matt Smith did not find the effect is accordingly good evidence against
the old quantum theory and for the new. I am now working on the new quantum mechanics,
for I think that atomic and molecular chemistry will require it. I am hoping to learn
something regarding the distribution of electron-orbits in atoms and molecules.
I talked with Professor Ewald in Stuttgart about crystal structures. He asked me particularly
if it would not be possible for us to publish such papers regularly in the Zeitschrift
für Kristallographie. Wyckoff, Bragg, and others are now doing so. He does not want
a paper to be represented there, as Wyckoff has done, but wants an abstract of it
only if it is published elsewhere. Papers of purely crystallographic interest should
be published there in full, I think. He would like us to send him, say once a year,
a review of our own crystal work for publication also. He said that perhaps in a couple
of years they would publish papers in their original language; at present he is willing
(not anxious) to translate them.
I should like to have your advice in regard to my publishing papers during this year.
Do you think I should publish in the American journals? I prepared a paper for the
Zeitschrift für Physik; but now I have to revise it, including the new quantum mechanics.
The German publications seem better than ours in one way- in the Zeitschrift für Physik,
for example, papers are often published in six weeks after their receipt. Also, would
the Institute like reprints of my papers, and if so, how many?
I am sure that you will enjoy spending the summer in your new house at Balboa. I send
best wishes to Professor Sherrill.