247
or
six
the
and
times.
were
uf all the
five
average
fmwu
usuallyrepeated
taken.
readings
were made at
varying
Experiments
pressures
150
Special Articles.
ON THE
to
in
fuund
taken
mm.
down
given
1000
the
mm. ;
averages
pressure
are
and
1.
com-
uf the
Table
(foi,
readings
the
fur the
averages
oxygen
pressures.
parison)
ignition-points
from
uf
in
curves at the
the
hydrogen
IN
CASES
IGNITION-POINTS OF
NITROUS OXIDE.
corresponding
TABLE
irr
Nitrous
of
I.—IgnOitxiyong-eponints Different
Hydrogen
BY H. B.
PROFESSOR
DIXON,
OF CHEMISTRY
D.SC., F.R.S.,
IN THE UNIVERSITY
C.B.E.,
Oxide
in
ot
an
Pressures.
OF
MANCHESTER.
AT
the
of
of the
Anesthetics C’ommittee
request
the Medical
Research Council
and the
Iloval Society
of
I
have made
gases
onthe
Medicine,
ignition-
experiments
of
certain
of
with
into
an
when introduced
points
nitrous
and have
gases
such
in air
and in
atmosphere
oxide,
compared
of
those
The two
the same
lgnitions
ygen.
and
account of their
gases, ethylene
propylene,
are of
interest
on
special
medically
use in
and of the
othmeraysupepxoprltoedres
anaesthesia,
producing
proposed
violence with which these
mixedwith
gases
or with
great
It is evident from these
that the
different
figures
that
in
ignition
pressures
ignition
or
when
air,
oxygen
of
in
oxide at
nitrous
general
hydrogen
such as nitrous oxide.
the literature of the
of combustion
follows the same
rule
gases
the
governs
it
gases
On
wasof
in
consulting
subject
and
crucial
and
air.
in
other
hydrogen
oxygenof
little
of
to tind how
the flames
is
a
that
There
the atmo-
surprising
pressure—about
had been studied.
oxide
he discovered
nitrms
when
J1o7s76e&pmdhash;calling
Priestley.
and below which the
sphere—above
ignition-point
in
it
the
gas
of
falls.
In
case the
every
hydrogen
ignition-point
Nitrous Air "-describes a, candle
in
oxide is lower than in
conditions.
under
the
oxygen
nitrous
"Dephlogisticated
with
large
a
much
in the
flame.
and
a,.
enlarged
gas
burning
corresponding
as it is
five or six times
twice as
"sometimes
naturally,
less than
also observed
when
sometimesnot
EtlaJlcrre and Propylene.
burnin nitrous oxide
larger."
the
in size
increase
into
Both
with an
central
and
Davy
Humphry
ethylene
propylene
an
tit
the
the candle-flame
flame
luminous
gas.
plunged
having
intensely
enlarged
formed
that the heat
the nitrous
have
the
He seems to
also form with
nitrous oxide
ignition-points
opinion
zone ;
they
tlf
first
the
mixtures.
The
burning
decomposed
body
explosive gas
highly
a
of
combustion was the result
that the
and
oxide,
of
determined in the same
were
into the
these
gtasheesm
way by
Inflammable
direct
withtheliberated
union
concentric-tube
oxygen..,
bringing
II. apparatus
and III.
madeat different
"
coln-
for their
tnnlics in
he writes.
general."
In
tilled with -nitrous oxide.
Tables
readings
require
oxide
they
bustion in nitrous
much
burn in air or in
the
of the
with
are
higher temperatures
average
compared
given
tlian
Most
"pinion,
those at which
modern writers
but our
for
those found
the same
oxygen."
pressures
gases
to
are
have followed
in
under
same conditions.
the
Davy’s
appear
oxygen
in
accord with
not
our
experiments
in
TARLE
Nitrous
this
tower
and
below that at
nitrous
tested in
nitrous oxide than
have
oxygen,
of
Ethylene
view. All the
II.—IgOnixtyiogne-pnoints
gases
in
apparatus
Pressures.
Oxide and in
at
in
Different
ignition-points
found at
are
these
ignition-points
temperatures
of
which the thermal
appreciable.
decomposition
is
oxide
Hydrogen.
As
oneof
the
the
of
of
is
in
burning
hydrogen
oxygen
prohably
"
reactionsinitiated
natural to start
the
temperature,
of
flame
simplest
at
the
"f
it
definite
it was
in nitrous oxide with that
flames
investigation
hydrogen.
On
an
of nitrous
oxide round
in air with
observed
bringing
atmosphere
The
for
mm. ;
in nitrous
crucial
oxide
ethylene
pressure
ethylene
a
small
of
pressure
is
which
the
jet
hydrogen
burning
is seento beabout 500
at
this
a
non-luminous
in the
flame,
the
name
fiye.
becomes
change
atmo-
At the
within half
a
second at
C.
605"
of
of
ignites
character
diameter
)-.
is
flame
most
remarkable : the
at 592°
ethylene
C.,
spheric
ignites rapidly
the
ipsressure11°C.
is
while its
height
doubled,
in
which
below the
only
ignition-point
The
central core
a
multiplied
by
(of
pale
in
but when the
are
contact
oxygen ;
with
mingling gases
and the
luminous,
colour)
apricot
spectrum
continuous from red to
a
the
heated surface the difference between
it
to
be
given
nolet.by
appears
is more
Under the same
lower
marked.
ignition-points
at
conditions
a
ethylene
temperature
but at low
ignites
In the
nitrous
determinations
a
flow of
following
steady
in
nitrous oxide
in
than
fails to
the
oxygenw;hen the
pressures
oxide
was
a
a
through
upwards
large
passed
of
exceeds
ethylene
ignite
in these
used
lag
while
wasintroduced from
jet
hydrogen
cylinder,
one second.
The
to time from
middle of the
a
narrow central
in
tube
lags
time
opening
was
The
gases
the
between
the
ethylene
experiments
mainly
cylinder.
in
and condensed
steel
that
the British
of
two
and
the
of contact
the
moment
cylinders by
prepared
appear-
of the
a
This
contains
asthe
lag ")
of
ance
the flamewere
noted,
Company.
gas
Oxygen
temperature
small amount of
interval
between the issue
the
furnace rises
impurity (chiefly
very
but
and
nitrogen),
prepared
(’’
the same
in the
as that
I.f
this
until
then
slowly.
its
and
decreases
the
gave
purified
propylene
from
normal
ignition-points
ignition gradually
gas
current is
a
the
half
becomes
laboratory.
second ;
temperature
fall
allowed
to
reduced
the
usedwas
in the
isopropyl
and
The
prepared
laboratory
alcohol.
A
the
then made while
are
of observations
and from
second
both
In
series
propyl
"
of
The mean
the
increases.
formed in considerable
case ethers were
each
quantity,
" lag
gradually
for
each
is
The two
be
the
and washed
in
and had to
condensed
propylene
and
the
readings
lag
descending
ascending
taken
as
that
for
was tested
from the
the
When
lag.
gas.
ignition-point
series
of
at
it
andfalling
concentric-tube
ignited
ordinary
rising
apparatus
readings(with
temperatures)
Dixon, H. B.
