Orange County observer. [volume] (Hillsborough, N.C.) 1880-1918, 1882-02-25
ALna1gans.

Op Mon is still divided with regard to
the nature OF amalgams, some considering
them TO be lsomorphous mechanical mix
lures. others true chemical compounds
The former. View derives support from
those cases In which analgamation is as
scciatci with al absorption OF heat, as in
tire so''ticn of salt o. IN dilutioa Of q
solution; the latter is supported by he fac,
tuat many amaigxins are formed with
strong development Of heat. A cOauibu-
tion to the subject has been lately made
by Herrcn Me'z and Weith, in the Berlin
Chemical Society. These chemists have
Investigated whether, with regular heating
amalsams part with their mercury con-
tlnnously or in distinct gradations
The experiments consisted IN placing
the amslgam in a porcelain dish within a
glass tube, contracted below, and inclosed
in second tube, having bulb at lis lower
end. This bulb of the outer tube
contained the substance Of the
varor bath (sulpnu-, or diphen, laminc).
To guard the snalgan from air, lively
current of an indifferent gas was passed
through the interior tube while the expert
mcnt lasted. The analgau.s used, which
we always directly produced by known
meth DDS. contained on an nveage 80 to so
per cent cf mercury. This heating was
continued wherever possible, until after
several hours no Gecrea-c OF weight (,r
hardly any, was perceptible. There were
examined gold, silver, copper, lead, tin,
bismuth, Zlnc. cadmium, and potassium
| amalgams. The results fer the first eight
are very briefly communicated, those fer
the last two, whose easy oxiGablity re-
/ quired special precautions, more fully. In
| the &c Of these alkai amaigams the
| authors also sought to determine the-snelt-
| ing points, but, for Oertain reasons. very
! accurate results wer not reached. In gen.
elal the melting points of the amalgans
rise at first very quickly with the prppor-
tion of alkah metal, then gradually tall. 1t
was thus observed that when mercury- is
heated under paraff1n to $50 ce, AMI then
some sodium is added in portions. the
whole mass soildihe5 with four to FIVE per-
cent Of sodium; but with further addition
some ercentage5 the mass fuses complete
ly.
The results Of their investigation are
summed up by the authors as follows: A
survey of the results described shows, for
. series of ana gam, hat even with mOder-
ate heating they do not furniah determnate
compounds.
The amalgams of gold, silver, copper,
bismuth, lead, tin, ZINC and cadmium lose
their mercury entirely, or nearly so. even
at or under the boiling temperature Of ner-
curry. Where no mercury remained, the
cause is to be sought rather in mechani
cal exclusion than in a chemical action.
But. on the other hand. the easy decon1-
possibility Of these amalgams evidently
offers no proof that there are no chemical
compounds in them.
For the rest, If we consider the great
variability of amalgams, together with the
fact that, in squeezing the so-caled mcr-
curry solutions of metals these latter dc
not remain behind, but certain mercury
compounds, the view acquires the greatest
probability, that at least very many ANAL
gains may be, indeed, molecular comblna
tons, but in fixed relations.
Most pronounced does chemism appear
to re in the amalgams of potassium and
sodium. They lose their mercury ext-emlJ
slowly, even at the boiling point OF sui
phur, as also in a gas current, and SO il
circumstances highly favorable to removal
Of mere mixed substances. The remark
able relations, too. as regards the melting
point, seem to speak for the presence O
true chemical compounds. Probably
these amalgams, at a comparatively low
as well rs a. q high-temperature, consls
Of different compounds, none Of which
however, have durable existence, ant
therefore reculrcnt, fxei relations o
composition are not TO be met with. Aikali
metal amalgams of fixed composition
would probably be obtained on production
Of larger quantities of amalgaln; perhap
also by heating considerably above tn
boiling temperature Of mer curry.