The Seattle post-intelligencer. [volume] (Seattle, Wash. Terr. [Wash.]) 1888-1914, 1900-12-30

chemical compounds in combination. In
1901 Davy. propounded the theory that all
compounds consist of two portions. one
electro-positive and the other electro
negative. This idea was the result OF ex-
periments on the behavior OF substances
such, for example, as copper and sulphur;
II portions of these elements be insulated
and then brought into contact they be-
come oppositely electrified The degree
OF Identification Is intensified by rise of
temperature until. when combination en-
sues, the electrihcation vanishes. Com
bination. therefore, according to Davy, is
concurrent with the equalization OF poten-
tails. In 1912. Berzelius brought forward
an electro-chemical theory which for the
Following twenty years was generally ae-
cepted- His primary assumption was that
the atoms OF elements. or. in certain
cases, groups OF atoms. are themselves
electrified that each atom, or group or
atoms; possesses two poles. one positive.
OF one or these poles predonnates over
that of the other. 50 that the atom or
group Is itself. as a whole, electro-positiye,
or eiectro-negative: that combination en-
sued between such oppositely electrified
bodies by the naturalization, partial or
complete, Of their electric charges; ana
lastly, that the polarity of an element
or group could be determined by noting
whether the element or groap separated
at the positive or at the negative pole
q the galyanic battery, or eiectroiysls .
electromagnetic and potassium the most
electro-positive OF the elements. the bridge
between the ''non-metals and me
metals being hydrogen. which, with
nitrogen. forms a basic, or electro-p posi-
tive. group, while with chlorine, etc, u
forms electromagnetic groups. The fact
than an electric current splits compounds
in solution into two portions. led Berzelius
TO devise his "dualistic" system, which
involved the assumption that all COM
pounds consist OF two portions, one cleo
tro-posItive, the other electromagnetic.
Thus sulphate of magnesium and potas-
stun was TO be regarded as composed OF
electro-positive potassium sulphate IN
combination with electro-nesative mag
nesium sulphate: the former In Its turn
consisted OF electro-negative sulphur
trioxide 500 in combination with electro
positive oxide of potassium tk4O)i while
each of these proximate constituents Of
potassium suphate were themselves
composed OF the electro negative oxygen
in combination with eleetro-positiye SUI
phur or potassium. On contrasting sui
phur with potassium, however, the former
was considered more electro-negatiye than
the latter, so that the group SOS as
whole was electromagnetic, while ksO
was the eiectro-postive. The symbols
given above which are still In universal
use were also devised by Berzelius for
the purpose of illustrating and emphasiz-
ing his views. These views. however, met
with little acceptance at the time in Eng
land.
I.avoisier's idea, that oxygen was the
necessary constituent of all acids, began
about this time to lose ground For Davy
had proved the elementary nature OF
chlorine: and hydrochioric acid, one OF
the strongest, was thus seen TO contain
no oxygen, and Davy expressed the view
founded on his observation, that iodic
"acid." los. was devoid Of acid proper
ties. until dissolved In water, and that
the. essential constituent OF all acids was
hydrogen. not oxygen. The bearing OF
this theory on the dualistic theory is, that
while. O. g., sulphuric acid was regarded
by Berzelus as SOs, containing no hydro-
gen, and was supposed TO be separated as
such at the positive pole of a battery,
Davy's suggestion led TO the opposite con-
clusion that the formula OF sulphuric acid
Is H.SO.. and that by the current II Is
resolved into Ha and So. Faraday''s
electrolytic law, that when a. current Is
passed through electrolytes in solution
the elements are liberated in quantities
proportional to their equivalents, led TO
the abandonment OF the dualistic theory.
For when a current is passed In success.
sion. through acidified water. fused lead
chloride and a solution OF potassium sui
phate. the quantities OF hydrogen and
oxygen from the water, OF lead and chic
rim from the lead chloride. and the pot
with Faraday's law. But In addition 10
the potassium, there Is liberated at the
same pole an equivalent OF hydrogen.
products should be 500 and Kso. but IL
the opposite view be correct. then x, Is
liberated first, and by its subsequent
action sn sa OF yre eas poTa s @ %as
lessor at Kings college. London, and
~ , was ssss assn. ssrueus sysseu
In 1889, too. Graham investigated the
phosphoric acids, and prepared the salts
OF three, to which he gave the names.
ortho-. pyro- and meta phosphoric acids.
To understand the bearing OF this on the
doctrine OF duaiism II must be remember
cd that Psos. pentoxide Of phosphorus,
was at that date named phosphoric acid.
When dissolved with water II reacts
with bases, forming salts-the phosphates.
But the quantity OF water necessary was
not then considered essential Graham,
however, showed that there exist three
series OF salts. one set derived from
Psos. 3Hso; one from Pos lHso, and a
third from Psos. fIso. HIS way Of stating
the fact was that water could play tho
part OF q base; for example. the ordi-
nary phosphate of commerce possessed,
according 20 him, the formula PsOs- 2NasO.
Hso. two thirds of the water OF consti-
tuition" being replaced by oxide of So
dunn. Iiebig then professor at Giessen
tlSo2-iSi3), founded ON these and on SINH
lar observations OF hts own the doctrine ~
polybasic aeids--aoids In which one two.
three or more atoms of hydrogen were re-
plaeeable By metals. Thus, instead of
writing. as Graham did, Psos2Nago. Hso.
he wrote Po.NasH: and for orthophos-
phorlc acid pO.Hs The group Of atoms
tpO.l, therefore existed throughout the
whole series of orthophosphates. and
could exist in combination with hydro
gen. with hydrogen and metals, or with
metals alone, Similarly the group PgO1l
was ehacteristic Of pyrophosphates and
IPpa) of metaphosphRtes. for PsOs.2 20
Pso1H.; and Psos Hso=2(PoDH-
The first clear ideas OF the structure OF
the molecule were. however gained from
the study OF the compounds OF carbon.
II was difficult 20 apply the dualstie tho
ory to them. For few Of them are cleo
trolytes, and therefore their products II
eiectroiysis, being nonCxtstant, could not
be classified. Nevertheless Lussac
regarded alcohol CHIC. as COM
pound OF CsHa. ethylene, and Hso. wafer.
and oxalic acid tanhydrousl Goa az one
az CO, with CO. The discovery OF 'iso-
merle compounds" C.. OF compounds
which possess the same ultimate formula
and yet differ entirely In their properties
forced upon chemists the necessity ot at
tending 10 the structure Of the molccuie;
for only by such superstition could the
difference between Two ismsric bodies be
explained. In las IAebig discovered that
silver illuminate and silver cyaaato both
possessed the enpirtcal-formula AECNOt
In iseS this was followed by the discovery
by Faraday that oil gas contains a hydro
carbon Identical In composition with ethy-
iens. Gill;. yet differing from Il In prop
critics. and In is39 Wohler. professor n
Gottingen CiSo0-iSSA. discovered that urea.
4