DOCS.
431,
432 JANUARY
1918
439
431.
From
Hugo
A.
Kruss
[Berlin,]
Ministry
of
Culture,
6
January
1918
Esteemed
Professor,
Many
thanks
for
the
interesting
statement
by
Schweydar.[1]
Concerning
Dr.
Freundlich,
I
spoke
with
P[rivy] C[ouncillor]
Müller of
the
Astrophys.
Obs. in
Potsdam.[2]
He would
like
to consider
the
matter for
a
few
more days.
Perhaps
you
could
provide
him with
a
few
more
details
about the
matter in
a
few
lines and
persuade
him
a
little.
With
best
regards, yours very truly,
Krüss.
432. From
Pieter Zeeman
Amsterdam, 158 Stadhouderskade, 8 January 1918
Highly
esteemed
Colleague,
With the
same post
I
permit
myself
to send
you
as
printed
matter
a
short
Dutch
paper
about
some
experiments regarding gravitation
as
well
as on
the
inertial
and
ponderous
mass
of
crystals
and radioactive substances.[1]
I
hope
that
you
will
allow
me
to indicate
very briefly (also
because
the
English
translation
of
the
paper
is
not
yet
ready)
the
results
of
the
communication.
1° Weight
determinations
of
quartz
spheres
with
horizontally,
then
vertically po-
sitioned
axes
prove
that
at
the
new
orientation,
the
weight
does
not
change by
1
to
26 000
000.-These
experiments
were
conducted
a
while
ago.
2° Experiments
with the
torsion
balance,
performed according
to
the method
by
Eötvös,
on
quartz cylinders prove
that
an
influence of
the orientation
of
a
quartz
crystal
on
the
proportion of inertial and
ponderous
mass
must
be smaller
than
1
to 30
000
000.
3°
Similar
result
for
calcspar.
4°
As
regards
radioactive
substances,
it
is
shown
that
for
uranyl
nitrate,
the
proportion
mentioned deviates
less
than
1
to
5,000,000
from
the
proportion
of
masses
for
quartz.[2]
In
the
case
of
uranium
oxide, initially a larger discrepancy
was
found,
which
is probably
attributable
to
admixtures
of
traces
of
iron.