DOC.
331
DECEMBER
1911 241
331. To
Michele
Besso
Prague,
26
December
[1911][1]
Dear
Michele,
I
am
taking pen
in
hand
feeling guilty as
usual
.....
It's
just
that
you
scared
me
with
your many
questions,
which
I partly
did not
understand
and
partly
did
not
know how to
answer,
so
that
I could not
bring
myself
to
write
you.
I have
made
no
headway
with the
electron
theory.
In
Brussels, too,
they acknowledged
the
failure of the
theory
with much
lamentation but without
finding
a remedy.[2]
In
general,
the
congress
in Brussels
resembled the
lamentations
on
the
ruins
of Jerusalem.
Nothing
positive
has
come
out
of
it.
My
fluctuation
arguments
met with
great
interest
and
no
serious
objection.[3]
I
did
not find it
very stimulating,
because
I
heard
nothing
that
I
had
not
known
before.
Recently
I wrote
a
short
paper
on
residual
rays.[4]
Rubens had
his
experiments
wrong.[5]
He
sought
to determine the
wavelengths
of the
residual
rays
of NaCl
in the
following
way:
NaCl
plates
Jamin's
interference-quartz plates
NaCl
source
A
thermoelement
[source;
NaCl
plates;
NaCl;
Jamin's
interference-quartz plates; thermoelement]
If the residual
rays
were
monochromatic,
then the
intensity
I
(indicated
by
the
thermoelement)
as a
function of
the distance
between
the
plates A
would be
as
follows:
I
A
But what was found was the following:
thus,
a
sort
of beats. Rubens
interpreted
this
as a
kind of
beats
resulting
from
the
fact
that there
are
two
almost
monochromatic residual
rays
in the beam,
NaCl
two proper