Kansas agitator. [volume] (Garnett, Kan.) 1890-1905, 1899-01-20
MICRO METALLURGY.
A New Science n.,1 It's Application to
Common Uses.

Tho Philadelphia Record tells in an in
teres.ing way how. during the past twenty
years, metallurgists in Europe and in this
country have discovered that the micro
scope can be used to reveal the hitherto
hidden molecular structure of metals. A
piece of steel, bronze or any other metal
may he prepared for this examination by
grinding it to a fiat surface, then polishing
it with the finest emery dust, rubbing it
for long time upon a smooth surface of
some soft, yielding material free from
grit. like pitch I'm order to remove all
scratches, and lastly by immersing 1t for
few moments in Il weak solution of acid
to develop its crystalline structure. The
specimen is then ready for examination
under the microscope to study its micro
structure. 1t is not an exaggeration to
say that the revelation is as striking to
the astonished oeholder as is the effect
produced by looking for the first time at
the moon through a powerful telescope.
The surface Of the metal. which 20 the
unaided eye appears as smooth as velvet
is now seen to be broken up into bands.
ridges and peaks. some of which reflect
the light with dazzling brilliancv, while
other portions appear as IL In deep Shad-
ow. When alleys of tw metals Of differ
ent colors-such as copper and silver, or
copper and tin-are treated in this way,
1t is even possible to identify particles of
the different metals by their different
colors. Very recently a bronze cent was
thus prepared by an investigator by filing
away the design upon one surface. then
polishing and etching It In acid. sim
liar disk was prepared in the same way
from bronze metal which had bsen simply
cast into shape without being subjected
to pressure When examined under the
microscope the molecular structure or the
cast disk was found to be entirely differ
ent from that of the coin-as much so as
though the specimens were composed OF
entirely different metals. The surface or
the bronze cent consisted of very fine
CRYSTALS, closely woven together in a reg
ular pattern. while the surface OF the
cast metal showed very irregular group
ings of coarse crystals, with spaces be-
tween. Moreover, the portion of thu latter
disk near the edge presented very
different appearance from that near the
center.
One important practical result of these
microscopic examinations of metals has
been to indicate thai alloys are In reailty
solutions of one metal in another and
that when the point Of saturation has
been reached the metal in excess is SIM
ply mechanically distributed throughout
the mass Of the entire alloy The metal
in excess Is, however, still! capable OF
Disabling n certain quantity of some 9TH
oIsaoiNtn5 ,,,, w. Satmrafing noint for
i.o'ai u.,' t. rooo,,od. ond 60 On al
most without limit. A familiar illustra-
eloi' may ,,, o s,,ai,,a oor, in or,ourt of
"d wa. w 49,. .,,'t ,ta colt u,oter will
SAT- SAT- anu ',o i'o'' ,,,,t', ~ s,,sor and
sun uis .,n '..tnii;,o so,ts NAV he dis.
namy JIM =, ,,,,,inb 10. oirood, heen
soiveu II, VIZ VIZ ,,,,n, so,t ond ,ugor
sa.ula'eu miom IN ,,,a,i t,ror,n fnct is
. r ,oS ,a,, ba tii,ed to the brim
that tu'"o,el nids We ny a,. 49,,
sHu "a coHSIuet"p'e uuai.i.S VI ~, Iii III;
De auoeu witnou, any ny. -. 80, ha
OF inc water. .nem sun! ., su .a.o ~ o,,or
adueu witnou, caus,'is w 49,, ' Ell, ho
HOW We siaIa' c a,' .,,,io ,,,i,tot ca,,S.