The sun., 1900-12-30

| forming an oxide OF carbon, carbonio oxide.
| on the one hand. or carbonic acid" on the
J other, while the metal is reproduced in
| its "regulne" or metallic condition. and
| that the true elements are metals, carbon
! sulphur. phosphorus and similar bodies.
and not the products Of their oxidation
The discovery that air II. In the main. a mix
| ture Of nitrogen. an inert gas. and oxygen.
| an active one. together Win a small pro
| portion of carbonio acid" (or, as 1t Is now
| termed, anhydrideJ-a discovery perfected
| by Rutherford. Black and Cavendish--and
| that water Is compound with oxygen OF
| hydrogen. previously known a. inham-
mable air. by Cavendish and by Watt,
| finally overthrow the theory of phlogiston,
| but at the beginning OF this century 1t still
| fingered on and was defended by Priestley
| until his death in 1904. Such. in brief,
was the condition OF chemical thought
in the year 1890. Scheele had died in 1885.
at the early age Of a; Lavoiser was one
of the victims Of the French Revolution.
having been guillotined in 1894: Cavendish
had ceased to work at chemical problems
and was devoting his extraordinary abili-
ties to physical problems Of the highest
Importance. while living the Life Of All ec-
centric recuse. and Priestley. driven by
religious persecution from England 10 the
more tolerant shores Of America. was enjoy
ing a peaceful old age enlvened by ocCa-
sional incursions into the region Of sec
tartan controversy.
FIRST STRIKING DISCOVERY or THE
CENTURY.
The first striking discovery Of our CEN
tury was that OF the compound nature OF
the alkalles and of the alkaline earthS
This discovery was made 10y llumphry
Davy Born in Cornwall in i77s. he began
the study of chemistry, self-taught. in liv6,
and In 1890 he became director Of the Pneu-
matte Institution" an undertaking founded
by Dr. Beddoes at Bristol for the purpose
Of experiments on the curative effects OF
gases in general. Here lie at once made
his mark by the discovery Of the remGka-
BILE properties Of laughing gas," or nitrous
oxide Al the same time he constructed
a gavanic battery and began TO perform
experiments with it in attempting to de-
compose chemical compounds by its means.
In ls0l Davy was appointed professor of
ciety or club which had been founded a
few years previously by Benjamin Thom-
son, Count Ruinfori. for the purpose of
instructing and amusing its members with
recent discoveries in chemistry ami natural
philosophy. In 1907 Davy applied his gal
vanic battery to the decomposition Of damp
cau-tic potash and soda. using platinum
poles. He was rewarded by seeing globules
Of metal, resembling mercury IN appear
ance, at the negative pole. and he sUb-e-
cuently proved that these globulcs, when
burned. reproduced the aika from which
they had been derived. They also conn
bined with "oxymuriatic acid" as chlorine
discovered by SCheeieJ was then termed.
forming ordinary salt, If sodium be- enl-
ployed. and the analogous salt. "muriate
of potash" il the allied metal. potassium.
were subjected to combustion. BY using
mercury as the negative pole. and passing
a current through a strong solution Of the
chloride OF calcium. strontium or barium.
Davy succeeded in procuring mixtures
with mercury or "amalgam," OF their
metals. To which he gave the names
calcium, strontium, and barlum. Distilla-
tion removed most Of the mercury. and
the metal vas left behind in a state Of
comparative purity. The alkai metals.
potassium and sodium. were found to
attack glass liberating the basis Of the
slick" To which the name silicon has since
been given.
Thus nearly the last ~ the "earths"
had been decomposed, 1t was proved
that not merely were the "ca!ces" of iron
E,r p,1l ly,,.,, ~
compounds of the respective metals with
oxygen. but Davy showed that lime and
it, allies. strontia and baryta. and even
silica or flint, were to be regarded as oxides
OF elements Of metallic appearance, TO
complete our review Of this part OF the
subject. suffice il TO say that aluminium, a
metal now produced ON an industrial scale,
was prepared for the first time in 1921 by
Wohler, professor OF chemistry at Gottlngen.
by tine action of potassium on its chloride
and alumlna, the earthly basis Of clay,
was shown 10 be the oxide of the metal
aluminium Indeed, the preparation Of
this metal in quantity is now carried ont
at Schairhauscn-on-the he Rhine and at the
Falls Of Foyers in Scotland by electrolysis
OF the oxide dissolved in melted cryolite.
u
sodium and aluminium. by a method DIFF
ferinE only in scale from that by means of
which Davy isolated sodium and potassium
in 1909,
DAVIS IMPORTANT WORK.
To Davy. too. belongs the merit Of hav-
Ing dethroned oxygen from its central
position among the elements. Lavoisier
gave To this important gaS the name
oxygen" because he imagined it to be
the constituent OF all acids. He renamed
the common compounds Of oxygen in such
manner that the term oxygen was not
even represented in the name only in
ferred Thus nitrate" Is Il compound
OF an oxide OF nitrogen and an oxide of a
metal; "sulphate." Of the oxide of a metal
with one of the oxides Of sulphur. and 80
on. Davy. by discovering the elementary
nature Of chlorine. showed first that il Is
not an oxide of hydrochloric acid Tor mIria-
tic acid. AZ it was then called; and, second.