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

| Strassburg nSiG-1S5G) emphasized the fact
replace another without Parliamentary
| altering its chemical character, and also
that an atom OF hydrogen can be re-
| placed by a group of atoms or radical be-
having for the occasion like the atom of
| an element 1t is to Laurent and Ger
hzrdt that we owe the definition of an
| atom-the smallest quantity of an element
| which can be present in a compound; an
eduivalent-that weight Of an element
which combines with or replaces one part
| by weight of hydrogen; and moecule-
the smallest quantity which can exist in a
Tree state, whether of an element or a
| compound. They recognized, too. that
| molecule of hydrogen, chlorine, etc, con-
sists Of two atoms.
In 1919 Wurtz. professor in Paris psl7-
lsSD. and HOFFMAN,, then professor in
the College Of Chemistry in London, aft,
erward at Berlin QSls-ls92), discovered
series of compounds allied to ammonia,
| Mia IN which one or more atoms of n.y.
sd nagg We're replaced BY a group Or rad
| or phenyl (CsHO. Wurtz referred such
compounds to the ammonia type. They
all resemble ammonia in their physical
| properties-smell, taste, etc.-as wei as
| In their power of uniting with acids TO
! form salts resembling ammonium chic
componnds shortly aga af 4snsF i Wiiiaml
son. professor at University college, Lon
don us2i- >, added the water type" in
consequence of his researches on mixed
others bodies in which the hydrogen of
water might be regarded as replaced by
organic radicals. Thus We have the
series:
H.o. H.; CHI. O. H.; CHI. O. CHI: and
Mia; NlIs; Hes, NH(CHOs; and NtCHOs;
the first representing compounds fol-
lowing the water type, the latter the am
monia type. This suggestion had been
previously made by Laurent in 1876 But
Williamson extended his views to inor-
ganie compounds; thus. sulphurIc acid
double water type-HO. So. OH being
derived from Fl. Q. lH. HI o: II. the two
hydrogen atoms Enclosed in brackets be-
types Gerhardt added the hydrogen and
hydrogen chloride types, H.H. and H.Ci;
and later Kekule, professor In Bonn
The next important step was taken by
FARMLAND. professor in the Royal School
Of Mines. London; his work, however.
had been anticipated by Gum Brown
professor at Ednburg university in a
pamphlet even yet little known. 1t was
TO attribute to elements one or more
the name ''valency," and -the capacity OF
possessing valency was called ''quanti-
yalence; Thus hydrogen was taken as
''monad" or monovaient Chlorine, be-
cause IL united with hydrogen atom to
atom, Is also monad oxygen, having
the. power TO combine with two atoms OF
hydrogen, was termed a dyad, or d.
yalent; nitrogen triad, or triyalent;
carbon tetrad, or tetravalent, and
on. This is evident from inspection OF
the formulate of their compounds with
hydrogen, thus:
Instances of penta, hexa, and even
hepta-valency are not wanting.
This was the key to unlock the struc-
tnre Of chemical compounds: and Frank
lands views just stated. are still held by
chemists. The determination of the con-
stitution OF compounds chiefly those of
carbon occupied the attention of chem
lists, almost exclusively, until 1880. The
plan of action is much the same as that
or mechanician who wishes to initiate
complicated mechanism. He must first
OtSSeCE IL INTO GrOuDE of mechanical con-
trivanees; these are next constructed; and
they are finally built together into the
complete machine. In certain cases the
atoms OF carbon are arranged in chains
as, for example In pentyl alcohol:
HsC-C-C-C-C-O-H
He Hs II, Ha
each atom being tetrad, and its "afifni-
ties or powers Of combination, saturated
either with hydrogen or with those of
neighboring atoms of carbon: in others
they are in the form Of ring" as in
benzene the formula OF which was first
suggested by Kekule, or in both, as in
ethyl benzene. One or moro atoms OF
r,itrosen, or OF oxygen, may form part OF
the circle. as In pyridine, and furfurane,
and so on. BY means OF conceptions such
as these many interesting compounds
have been built up out OF the elements
acid. constituents of urine: theobromine
and caffeine, the essential principles of
cocoa and tea; alizarine and indigo, valu-
able dye stuffs: and several OF the aka
loids, bitter principles contained in plants.
OF great medicinal value.
They have led, too. to the discovery OF
many brilliant colors, now almost uni
| versally employed, to the exclusion OF
those less brilliant, because less pure. de-
rived from plants, and In one or two
cases from animals; the manufacture OF
gun cotton, dynamite and similar hgh
explosives; and to the development OF
! the candle Industry; the sugar manufac-
ture, to the Improvement In tanning. In
I brewing and IN the preparation OF gas
and oils for illuminating purposes. In
short, II may be said that the Industrial
progress Of the latter half Of the pres
ent century has been due to the theo-
retical views of which short sketch has
/ just been given
Such formulate, however, can evidently
not represent the true constitution OF
matter, inasmuch as the atoms are mag
ined 70 lie on plane. whereas 1t is evil
dent that they must occupy space OF
three dimensions and possess the attri-
butSs OF soldity. The conception which
led 10 the formulation OF such Views was
due first To Pasteur, In his later years d.
rector OF the institute known by his name
at Paris. and more directly TO LeBe and
Van & Hon, now professor at Berlin, In
dependently OF each other. In isss Pas
teur discovered that IL was possible 20
( separate the Two varieties OF tartaric acid
from each other, ana that one which rO-
T tated the plane OF polnrizcd light TO the
I right gave crystals with an extra face,
Z unsymmetricaily disposed with regard 20
4 the other faces OF the crystal. The va
I riety, the solution Of which IN water was
I tiOn, also possessed a similar face. but 80
I placed that its reelection Ia mirror re-
/ produced the right-hanaed variety. Pas
teur also showed that mixture Of these
acids gave crystals not characterized by
an unsymmetrCallY placed face. and also
that the solution was without action on
} polariEed light These observations re-
I NAMED unexplained until LeBal and van
I 4 Hen, ia 1874 simultaneously and inde-
pcndentiy devised q theory which has up
I til now stood the test OF research II Is
briefly this: Imagine two regular tetra-
Z hodra, or three-s sided pyramids standing
! each on its triangular base. An idea can
/ best hH got by a model. easily made by
laying on tahie three lucifer matches
] so as 20 form NJ eQuiiatcrel triangle ana
{ erecting tripod with three othere
{ matches. so that each leg OF the tripod
stands on one corner % the triangle. At
I the center OF such tetrAhedrau an
/ atom OF carbon u supposed 10 be placed.
/ Marsh gas, CH.. Is supposed 10 have such
I a structure. each corner or solid angle
I OF the structure (of which there are four
I being occupied BY ar atom OF hydrogen
I This represents the solid OF Etsreoeheniieal
I formula Of methane or marsh gas Now