FOUNDATIONS
OF
STATISTICAL
PHYSICS 43
Just
as
he studied
Maxwell's
electrodynamics on
his
own,
Einstein
pursued
his
interest
in
thermodynamics
and kinetic
theory
through
independent
reading.
Among
the first books
that he studied
was
Mach's
Wärmelehre,
which he
probably
read
in
1897
or shortly
there-
after.[18]
But
as
Einstein's
papers
on
statistical
physics
themselves make
clear,
Boltz-
mann's Gastheorie
was
the most immediate influence
on
his work in this
field.[19]
He
began an
intensive
study
of
Boltzmann,
perhaps
in the
summer
of
1899,[20]
and late the
following summer
he wrote:
I
am firmly
convinced
of
the correctness
of
the
principles
of
the
theory, that
is,
I
am
convinced that
in
the
case
of
gases
it is
really a
matter
of
the movement
of
discrete
mass
points
of
definite,
finite
magnitude
that
move
in accordance
with
certain
conditions.
. . .
It
is
a
step
forward in the
dynamical explanation
of
physical phenomena.
Ich bin
fest
von
der
Richtigkeit
der
Prinzipien
der
Theorie
überzeugt,
das
heißt
ich
bin
überzeugt,
daß
es
sich
wirklich
um
Bewegung
diskreter
Massen-
punkte
von
bestimmter endlicher Größe bei den Gasen
handelt,
die sich
gemäß
gewissen Bedingungen bewegen.
. . .
Es ist ein Schritt weiter in
der
dyna-
mischen
Erklärung
der
physikalischen Erscheinungen.[21]
Einstein continued to
study
the
Gastheorie
at least
through
the
summer
of
1901
.[22]
In the
spring
of
that
year,
he mentioned O. E.
Meyer's
widely
read text, Die kinetische Theorie
der
Gase,
as a possible source
of
empirical
data for
an investigation
of intermolecular
forces that he
was
then
carrying
out with
Maric's
assistance,[23]
and also asked Maric to
send him
a copy
of Kirchhoff's
Vorlesungen
über
die Theorie
der
Wärme.[24]
He
seems
to
[18]
See Mach 1896. Besso recalled
recom-
mending
Mach's
writings to
Einstein in 1897
or
1898
(Michele
Besso
to Einstein, 12
October-8
December
1947);
Einstein recalled that Besso
had
recommended
both the
Mechanik
(Mach
1897)
and the Wärmelehre
"during
my
first
years
of
[university]
studies"
("während meiner
ersten Studienjahre") (Einstein to Besso, 6
Jan-
uary
1948),
and
"about
the
year
1897"
("etwa
im Jahre 1897")
(Einstein to
Carl
Seelig, 8
April
1952).
A
copy
of
the second edition
of
the
Wärmelehre,
Mach
1900b, is
in
Einstein's
per-
sonal
library
and contains
a
few short
marginalia
in
Einstein's
hand. The earliest
extant
mention
of
Mach in
Einstein's
correspondence
is
in Ein-
stein to Mileva
Maric, 10
September
1899
(Vol.
1,
Doc.
54).
[19]
See Boltzmann
1896, 1898a.
A
copy,
with
the label
of
a
Milan book
store, is
in
Einstein's
personal library
and contains
a
few,
mostly
in-
significant marginalia
and inclusions in Ein-
stein's
hand.
[20]
See Einstein
to
Mileva Maric,
10
Septem-
ber 1899
(Vol.
1,
Doc.
54).
[21]
Einstein to Mileva
Maric, 13
September
1900
(Vol.
1,
Doc.
75).
Shortly
thereafter,
Ein-
stein sent Boltzmann
a manuscript copy
of
Ein-
stein 1901
(Doc.
1)
(see
Mileva Maric to Helene
Savic, 20 December
1900,
Vol.
1,
Doc.
85);
for
a
discussion
of
the
possible
influence
of
Boltz-
mann
1898a
on
this
paper, see
the editorial
note,
"Einstein
on
the Nature
of
Molecular
Forces,"
p.
4. Einstein's
sister
Maja
claimed
that Einstein
continued
to
correspond
with Boltzmann until
the
latter's
death;
but she stated that their
corre-
spondence
concerned the
theory
of
relativity
(Winteler-Einstein
1924, p. 18).
[22]
See
Einstein to Marcel
Grossmann,
6
Sep-
tember
1901
(Vol. 1,
Doc.
122).
[23] Meyer,
O. E.
1877, 1895, 1899
(see
Ein-
stein
to
Mileva
Maric,
30
April 1901,
Vol.
1,
Doc.
102).
For
a
discussion
of
Einstein's
work
on
molecular
forces,
see
the editorial
note,
"Einstein
on
the Nature
of
Molecular Forces,"
pp.
3-8.
[24]
See Kirchhoff
1894.
For the
request,
see
Einstein
to
Mileva
Maric, 15
April
1901 (Vol.
1,
Doc.
101).