Institute for Theoretical Physics
University of Munich
May 22, 1926
Dear Dr. Noyes,
We have been getting along nicely here; but we miss Pasadena, for everything so different
from what we had become accustomed to. Even in the Institute, things are done differently;
for example, the seminars are devoted to formal presentations of new papers, without
the invigorated discussion which we are accustomed to having; and the research problems
of the men themselves are not discussed or at any rate have not yet been discussed.
Instead it seems proper to do everything through Professor Sommerfeld, who holds private
discussions with the men here concerning their researches.
Yesterday I went with Professor Sommerfeld to the Deutsches Museum, where he suggested
some changes in the exhibits on the structure of matter and on optics. On introducing
me to one of the officials he said, “Dr. Pauling is from America, but he speaks very
good German.” Despite the fact that I know he was joking, I was pleased, for the remark
is untrue enough to be flattering. The Deutsches Museum is a marvelous place, with
an immense collection of exhibits, models, apparatus, etc; and it is kept up-to-date
through the efforts of the leading scientific and technical men. I saw, for example,
a model of a Flettmer rotor, which really worked: the wind was supplied by electric
fans, and the rotor, turned by an electric motor, was on a little car which ran back
and forth at right angles to the wind. In the section on the structure of matter there
are models of the hydrogen atom and the hydrogen mol-ion, of a number of crystals,
of solid solutions, showing atom-for-atom replacement, of metals, showing plastic
deformation through slip along glide-planes, and models of a number of organic molecules,
including a complicated dye and bees-wax, which looks like this- /\/\/\/\/\/\/\/\/\,
and is about four feet long. There is a fac-simile reproduction of Liebig’s laboratory,
and of an alchemist’s laboratory, and of others. Of historical interest are samples
of the original specimens of most of the elements discovered in modern times; Sancke’s
original space-group models; Van Hoff’s original tetrahedral showing stereo-numerism;
and many other things. I am glad that we shall soon have in America a similar museum.
I am enclosing an advertisement regarding crystal models. I now think that it would
be unwise for us to make these models at the Institute, since Selmayre, who is Sommerfeld’s
mechanic, makes them so cheaply. I do believe strongly that we should have a large
number of them; for I think it will continue our work in crystal structure. As far
as I am concerned the models will not be needed for a year and a half, and unless
Dr. Dickinson will want them for next year it might be well to wait awhile before
bringing them, for Selmayre said that he might reduce his prices, which are now about
$4 per model. I have checked about twenty-five, which would give us a good collection
of these handsome and well-built models, at a cost of $100.
Sommerfeld and Grimm have written an interesting article in which they conclude that
the shared-electron bond is present in a number of crystals, including AlN, BeO, ZnS,
AgI, etc. I agree in all cases but ZnS and AgI, and I am doubtful there. They have
shown thermodynamically that AlN does not consist of Al+3 and N-3 ions. Dr. Niesseu,
a Dutchman here on an International Fellowship, has made some calculations regarding
shared orbits. I think it probable that I shall make some later, too. Recently I have
been studying paramagnetism, and have found a new derivation of Langevin’s law (or
Curie’s law) for crystals. However, I just recently found a paper by Cabrera in which
he qualitatively and somewhat vaguely suggested the same thing, thus taking the edge
off my work. Yesterday I told Dr. Sommerfeld of my work on the quantum theory of the
dielectric constant of hydrogen chloride, and he was interested in it, especially
in the part (as yet unpublished) concerning the action of crossed magnetic and electric
fields. He said for me to begin work immediately on the problem of fields of any strength
(I had before considered one to be much stronger than the other), for he thought the
problem to have great theoretical as well as practical interest. He said that he would
present the results next month in Zurich at a congress on magnetism called by Debye.
I shall accordingly have to work to have results by then.
noticed in Physikalisde Zeit, 27, 165)1926) an article in which E. Ott applied the
powder method to determining size of unit and hence an upper limit for the molecular
weight and so the amount of polymerism of some organic compounds. Then later in Naturwissiuschaften
he reported a similar research on rubber. However, no one has yet reported a true
molecular weight determination. I am accordingly anxious ot learn how Kirkpatrick
has turned out in his work on K3Ni(NO2)6. I still think that it would be a fine thing
to make a molecular weight determination on insulin, in case large enough crystals
could be obtained.
Dear Dr. Noyes,
We are going Wednesday with some boys on a trip to the Bavarian Alps. We shall have
our first experience in real mountain climbing. I have an ankle which is a bit tender,
but I shall wear proper shoes.
Perhaps you will be interested to know that I can understand German conversation a
little now, and that I can even say a few things. Linus does nicely.
We are both very well and happy, and Linus looks much much better, which pleases me.
Mamma writes that Linus Jr. walks all around and that he is extremely well and happy.
We are enjoying Munich very much but we shall be happy to get back and Linus gets
really lonesome for the Institute.
We have seen several operas which were excellently done. Fortunately the price of
tickets is well within our means.
We saw Mr. Anderson and Mr. Ewing quite often when they were here. They too are enjoying
I trust everything is going nicely with you and the Institute.
Ava Helen Pauling
P.S. I study my German grammar daily and attend all of the lectures. One of the German
boys said that including myself there are five Americans in the Institute for Theoretical
I fear I don’t lend much to the department.
Ava Helen Pauling