The sun. [volume] (New York [N.Y.]) 1833-1916, 1878-01-27
C.fN IRON BE SECURED FROM RUST9

Aprocess by which iron may be preserved
from oxidation has been recently invented by
Prof. Barff and submitted To the London So
ciety Of Arts. 1t may be worth while to offer
some account Of an invention. which. IL 1t prove
susceptible Of practical application. must obvi-
ousy be Of great utility.
In order to indicate Jus, what Prof Barn pro-
poses to accomplish. We may call to mind the
familiar chemical phenomena presented in the
rustug Of iron. When W. expose n bar Of iron
TO a damp atmosphere, 1t is presently covered
with spots Of iron rust. In other words. spo-
radio disin,eeration takes place through the
combination Of the metal with the oxygen Of
the air to form sesluioxide Of iron. Another
Unknown combination OF these two sub
stances is the protoNidc and it is sufficiently
accurate for our present purpose to say that the
latter Is engrnlercd on the edges OF the rust
spots whore the sequioXide finds itself in pres
ence Of an excess Of iron. There is. on the
other hand. a third compound. known as the
magnetic oxide. which may be described as u
salt made up II the other two. and which pos
scssos the valuable property II undergoing no
mobilization whatever in n damp atmos phere.
Moreover. no variations OF temperature. such
as are encountered in the ordinary uses Of iron.
decompose it, or impart 10 it an excess II oxy-
gen. The latter fact will be readily accounted
for when We consider that the magnetic oxide
Is generally procured in laboratories by passing
current II aqueous vapor over iron filings
heated red hot. Obtained IN this way. II is. of
course. in "A pulverulent condition. and for
long time chemists had supposed that 1t could
not be reduced to a cohesive mass.
Prof Barn however. has now demonstrated
that not only are the particles OF the magnetic
oxide capable Of agglomeraton. but Of adhe-
sion in solid block to the surface on which
they are generated, 40 rs TO form a protecting
coat or shield which resists the action Of the
file. or Of emery paper, much better than the
iron itself To secure this adhesive layer Of
the magnetic oxide. he plunges the iron object.
say bar or rail- into furnace heated to a
temperature of 500 degrees Fahrenheit and
passes over il a current Of yapor. According to
! circumstances. tho treatment is prolonged for
/ five. six, or seven hours. after which the iron is
withdrawn covered with fake OF magnetic
oxide absolutely imprcgngblr 10 rust. Tho
temperature. Of course. would wary with tho
nature and use II the objects treated. To OBJ
tain. for instance. on the surface of highly poll
I ishrd steel a thick stratum. which should sup
/ port udciinittly the action OF water charged
with acid vapors. such a- are on 'ountored i'm
laboratories. it might be ne Hessary to heat the
furnace up To POO degrees. But With unpol-
ishcd iron, and for all ordinary purposes the
lower temperature nhove-namnl would SUM 'c.
Prof Barn aid before the Socirty of Arts a
number Of samples If iron coated hy his pro-
coss, and drew attention 10 another sp'cin
property resulting from this method of pr"s"r-
Walton. When we paint an iron bar, nnd the
paint is rubbed oll AT a single point IL Is woll
knownihat civilization -nt- in ana is propn-
gated with great rapidity. with the mneH tl'
oxide is not 50. but although "A spot ~ rn~'
will h'"hsoryol whore pllro has been laid