118
DOC.
159 MAY 1909
suitable.- First
I will
investigate a
whole series
of
gases
and
vapors
in
the
hope
to find
the
connection between
conductivity
and
optical properties (absorp.
etc.).-
Of
course,
this
is
only
between
us.
-
And
now
I
have two
requests
for
you. First,
I
invite
you
to
come
to Heidelberg
for
Pentecost.
You could
stay
with
me,
because
I
now
have
two
rooms
in
a
splendid location,
almost
in
the
country.
Second, I
would
very
much like to ask
you
to send
me a
photograph
of
yourself.
When
are
you
going
to
Zurich? What
are your
plans
for
the
big
vacation?
Perhaps
we can
meet in
the mountains?
Finally,
I would like to
return to
a
sentence
in
your
last
postcard.
You mention
there that
you
are
indebted
to
me
too for
the
appointment.
I
don't understand
that.
I
can
say only
this much: I
am
indebted
to W. Wien for
introducing
me
to experimental
physics;
it
is
you
whom I must
consider
as my
teacher
in
theoretical
physics.
While I
was
with
you,
I
learned
quite
a
few
other
things too,
and I
always
think of
my
time
in
Bern
with
great
gratitude.[6]
This
afternoon
I
experienced
a
nice litle
episode
with Dr.
Hertz.[7] Immediately
after
my
arrival in
Heidelberg,
H.
proposed
that
we
do
something together.
You
know
that
I have
done
experimental
studies
on
Roentgen
rays
(polarization, absorption,
etc.),[8]
and
that
I
also do
some
theorizing
about the
subject.
H.
lamented that
he
doesn't
have
any
work
to
do,
etc.
Because Hertz
is not
a
bad mathematician; he
understands
and
knows
only
a
little
about
physics, perhaps
even
less
than
I
do
about
his
mathematics,
for
example.
I
proposed
that
we
work
together
on
the
questions,
perhaps something
theoretical
would be feasible. I
suggested a
whole series of
ideas
(quanta
too
.
.
.
)
to
him,
and
we
threw
ourselves
enthusiastically
into
some
calculations. This
afternoon
he
unexpectedly came
to
me
with the
following, seemingly
naive,
but
in fact
quite
well-
considered
words:
He
would like
to
continue
working
on
Roentgen
rays
alone,
without
me;
he
must also
publish
a
paper
in
physics,
and this he
must
do
by
himself,
because of
his career!
(sic!).
"We
can always
talk about
it, etc.,
but
he will
publish
it
only
under
his
name."
I
answered that
he
is
absolutely right!
How do
you
like
that?
He
also wants
to
do
experimental
work with
me.
To
be
sure,
he
is
so
clumsy
that
Lenard didn't
want to
let
him into
the
institute, he tells
me
himself that he
would
only
be
in
my way,
he
would,
however,
like to do
an
experimental
study
because
of the
career!
I
told
him,
of
course,
that
I have
nothing against
it
as
long
as
Lenard
agrees.
But
you
can imagine
what
opinion
I
now
have
of
H.
This
is
what
happens
when
one sees
the
university as
the
only
salvation.
The
rich
German
Jews must
become
professors,
this
is
simply
what
their
parents bring
them
up
to
become.
But
they
often
want to have
people
believe
that
they
do it
only
in the
interest
of
science.
The
same
applies
to
the
rich
Prussian
bourgeois.
Perhaps
it is
improper to
write this in
a
letter,
but
it will
remain between
us.
I
just
had to unburden
myself
to
you.