EINSTEIN'S COLLABORATORS 489end. The open end is connected to an air pump. The empty tube is hung in a bath
of aether (chosen for its low capillary constant a). The aether fills the membrane
pores. The air pump serves to increase the pressure inside the tube until, at a
pressure p, air bubbles begin to appear in the aether. Then p = 4a/d. Here d is
the diameter of the widest membrane pores and is therefore the optimal colloidal
diameter to be determined. The authors record the results of experiments in which
diameters of about 1 /jm were obtained.
The friendship between the two men grew and became very important in Ein-
stein's life. Tor a long period, Einstein visited us daily in Berlin' [M2]. Mrs
Miihsam wrote to Seelig after her husband's death, 'Do you know that Einstein
once said to me, "First comes your husband, then for a long while comes nothing,
and only then come all other people"?' [M3]. I have reasons to believe that
Miihsam became Einstein's closest confidant in the Berlin days. It was to
Miihsam that Einstein told the story of having, at age twelve, composed songs in
honor of God which he would sing to himself on his way to school [S5] (see Chap-
ter 3). When Miihsam once asked what would have become of Einstein if he had
been born the son of poor Russian Jews, Einstein replied that he would probably
have become a rabbi [S6]. Muhsam could have informed us better than anyone
else about personal events which may well have contributed to Einstein's becoming
a figure who went his lonely separate way in physics after 1926.
Einstein and Muhsam kept in touch after the Einsteins had settled in the
United States and the Miihsams had fled from Germany to Israel. A letter from
Einstein in 1942 still shows personal touches: 'I have become a lonely old chap
who is mainly known because he does not wear socks and who is exhibited as a
curiosum on special occasions' [E27]. In that same letter, he also writes about his
work: 'In regard to work, I am more fanatic than ever and really hope to have
solved my old problem of the unity of the physical field. However, it is like an
airship with which one can sail around in the clouds without seeing clearly how
to land in reality, that is, on earth.' Muhsam died in Haifa in 1957.
- Leo Szilard. b. 1898, Budapest. He went to Berlin for his university
education. 'As soon as it became clear to Szilard that physics was his real interest,
he introduced himself, with characteristic directness, to Albert Einstein. I believe
it was largely Szilard's doing that Einstein gave a seminar on statistical mechan-
ics.... The seminar was a unique experience for most participants; it also
inspired, I believe, Szilard's doctoral dissertation' [W2]. PhD in Berlin in 1922
with von Laue. Until 1933 Szilard worked at one of the Kaiser Wilhelm Institutes
in Berlin. From 1928 to 1933 he was also Privatdozent at the University.
Einstein and Szilard made a considerable number of joint patent applications,
eight German (November 1927-December 1930), six British (December 1927-
December 1929), one U.S. (December 16, 1927), one to Einstein's old patent
office in Bern (December 21, 1928), and one Dutch (December 27, 1928). All
applications were granted except for two of the British ones. All the German pat-