The Lake Charles echo. [volume] (Lake Charles, Parish of Calcasieu, La.) 1876-1898, 1893-12-01
NO 40
solLMo FONTS
Tliess ARE worcestershire end Hsrpa css
saans staay.

These Ara fanuRaerable and Herui Gsla
saans Study.
Tt Il interesting ~ nota that si,a tsHss
perature It which 4 liquid bQ9la s. tbs
same as that at which its vapog IS coa-
denaad, precisely as tho temperature as
which waiter fieegos IN the saina ID that
Al which 40 ineits
At may seem superiiuous to oheerve
that there are more boiling points than
the boiling point of water e il were
not 10, all bodies would be ia the solid
liquid or gaseous state together and lifa
would Be Impossible. II ii partly tn
giving every substance lis own boiling
point On rather its own set pf boiling
points -for Tho fixed Temperature, even
Tor the same substance, y d afallacg
that nature has rendered ouF physical
environment suitable to cur needs.
What is generally understood BY the
boiling point Of water IS q Temperatures
Of 2t9 aegrees on The Fahrenheit thor
Inonetrio scale, but Alpine climb9Es
know we'll that, on q high mountain
water boils at very much lower tene-
perature on the summit Of Mont Rlano
at ls4 degrees The reason 4 that az
these attitudes, the pressure ee the at-
mosphere Is very much reduced, since
the density Of the air decreases with The
distance above the earth a sugface, end
the water expands at q coTresp9aaingty
lower temperature, passing more yaad-
lily into the vaporous condition, in which
the volume Of given mass e any sab
stance - always faT greater than thas
Of the same mass when liquid Tine
boiling point Of liquid iss therefore.
seen to depend not only on temperature,
but also on pressure, and the boiling
point Of water at 319 degrees coTra-
spends To what Is called - pressure or
one atmosphere, approximately t5
pounds to the square inch, 81 the pFes-
sure capable Of supporting the columu
Of mercury in 4 mercurial barometer
at q height of 500 inches. Thia ID
the average pressure Of the atmosphere
at the sea level, and Il it il reduced the
boiling point is lowered, while If IL IS
inoreased the boiling point is raised.
"a very curious result IA arrived "A
K we place q vessel of watar ia the re-
eeiver Of AZ airpump and reduce tho
pressure to 000 Of an atmosphere, for
then the water boils at 90 degree that
is at ita freoziug point under ordinary
pressure, Since II Is now possible To
produce an almost perfect vacuum,
water may be boiled at still lower tem-
peratures,
All liquids DO not boil AZ the same
Temperatures Thus, while water under
q pressure OF one atmosphere boils at
s12 degrees, alcohol, which passes more
readily into the state Of vapor, boila
at 179,a degrees and ether at a3. 3 do
grees, which Is below tho nornal tenn
peFature Of the body,
Since increase Of pressure retar6la tho
vaporization d d liquid, 1t Of course
facilitates the liquefaction of gas By
assisting the process of contraction.
Consequently many gases are capable
OF being hquefed By pressure alone,
though only when they are below what
Is called their critical temperature
tdifferent for every different gas, above
which cold as we'll Is pressure baeomes
necessary, Oxygen, hydrogen and nitro
gen are the most remarkable examples
of gases having low critical tempara
lures, and IL Is only recently that their
liquefaction has been accomplished at
all, They were long thought 70 be
''permanent gases, but Il ID now
kliown that all gases arc hquehahle.
The boiling points Of oxygen and MI
trogen are respectively 87b.s degrees
and 1856 degrees +. below the fraez-
ing point Of water, and therefore
these are the highest temperatures at
which they can exist as liquids. 70
produce these extremely low Temporal
lures It is necessary to employ great
pressure along with freezing mixtures.
Themost remarkable liquefaetion which
has yet been accomplished il that Of
air, 1t was supposed that, the oxygen
and nitrogen having different boiling
points, they would liauefy separately.
This Ia not the case; tile mixtura liques
fes as air and presents the appearance
of water, hut on being again eYaporRted
tho nitrogen evaporates FIRST and the OK
ygen afterward, This Is q puzzle II
phyaics which win doubtless ba ex-
planned era long Good Words.