Lab
Library
Journal
Shop
Sign in
to keep
Share image
1
177
The Story of Alchemy and the Beginnings of Chemistry
·
M. M. Pattison Muir
147
The
facts
which
were
available
in
Dalton's
time
confirmed
this
deduction
from
the
atomic
theory
within
the
limits
of
experimental
errors;
and
the
facts
which
have
been
established
since
Dalton's
time
are
completely
in
keeping
with
the
deduction.
Take,
for
instance,
three
compounds
of
the
elements
nitrogen
and
oxygen.
That
one
of
the
three
which
contains
least
oxygen
is
composed
of
63.64
per
cent.
of
nitrogen,
and
36.36
per
cent.
of
oxygen;
if
the
atomic
weight
of
nitrogen
is
taken
to
be
4.66,
which
is
the
weight
of
nitrogen
that
combines
with
one
part
by
weight
of
hydrogen,
then
the
weight
of
oxygen
combined
with
4.66
of
nitrogen
is
2.66
(63.64:36.36
=
4.66:2.66).
The
weights
of
oxygen
which
combine
with
4.66
parts
by
weight
of
nitrogen
to
form
the
second
and
third
compounds,
respectively,
must
be
whole
multiples
of
2.66;
these
weights
are
5.32
and
10.64.
Now
5.32
=
2.66
x
2,
and
10.64
=
2.66
x
4.
Hence,
the
quantities
by
weight
of
oxygen
which
combine
with
one
and
the
same
weight
of
nitrogen
are
such
that
two
of
these
quantities
are
whole
multiples
of
the
third
quantity.
Dalton's
application
of
the
Greek
atomic
theory
to
the
facts
established
by
the
analyses
of
compounds
enabled
him
to
attach
to
each
element
a
number
which
he
called
the
atomic
weight
of
the
element,
and
to
summarise
all
the
facts
concerning
the
compositions
of
compounds
in
the
statement,
that
the
elements
combine
in
the
ratios
of
their
atomic
weights,
or
in
the
ratios
of
whole
multiples
of
their
atomic
weights.
All
the
investigations
which
have
been
made
into
the
compositions
of
compounds,
since
Dalton's
time,
have
confirmed
the
generalisation
which
followed
from
Dalton's
application
of
the
atomic
theory.
Marker
Marker
Fine marker
White-out
Fine white-out
Circle
Paint
Unmarker
Hand
Scalpel
Dice
Sieve
Purify
Undo
Redo
Start over
