New-York tribune. [volume] (New York [N.Y.]) 1866-1924, 1873-09-29
CHEMICAL SCIENCE.
ADDRESS OF ALEXANDER W. WILLIAMSON Pm. d.
F. R. s., PRESIDENT OF THE ASSOCIATION.

ADDRESS OF ALEXANDER W. WILLIAMSON, Pm. D.,
Pr S. PRESIDENT OF THE ASSOCIATION
The celebrated physicist. DR.. Joule, was to
have presided over the meeting at Bradford, but the
condition his health not such to permit him TO
occupy the chair. DR.. Wiamson's address, after al
luding to the foregoing Circumstance, takes MP the
atomic theory Of the constitution Of matter Every good
ANALYSIS of pure compound leads results Which APP
proxmate to those required by the Atomic Theory; and
chemists thoroughly TO the truth OF that GUIDE
that they the results OF such analysis by the AID
of it, The chemical idea OF atoms serves for two pur-
poses: o. IL gives clear and consistent explanation
of an immense number of facts discovered by expert
men and enables TO compare them with one another
and TO classify them. a. 1t leads TO the anticipation OF
new facts by suggesting new compounds which may he
made at the same time it teaches that compounds
can exist with their constituents in any other than
atomic proportions aud that experiments which Imply
Inc existence of any such compound are faulty
Among the improvements OF our knowledge of atoms
eyanations Of the relative weight of of different
kinds which have been made since Dat0ns time more
record have shown that certain atoms are niue
heavier lighter than was then believed ana the o.
nerfectng observations constantly b0uS vi NIlh
The and OF better instruments ana methOds OF Operations
But apart from these special corrections, mort sMeep
mo change ms taken place. not IN consequence OF more
accurate experiments interpreted in the usual way Dut
i'm consequence of more eomprehehSlVs view vi
tho nest governmental results which had been OBJ
tanned and "a more consistent Interpretation OF them
Thus the atomic weight OF carbon had oeeh hAeu AZ ny
bumas's admirable experiments; and 1t was quite con
itahle that n SIM more perfect determination might
slightly increase or diminish TINS nuDer. De 10
substance mat two of these supposed atoms, whatever
SUE h te ,recise weight OF each always together
and never separate from another ana they accord
lngly applied the term atom TO that hdVslDe mas "a
carbon Weighing twice much as carbon atom mao
heen sunnosed to weigh SO also with regard TO other
elements IL has been shown that many atoms are really
twice IA heavy as had supposed according TO the
oTiSinsi Interpretation Of the best experiments
One Of the results OF our endeavors 10 CLASSIFY SUP
stances according TO their natural resemDances mas
heen of
among atoms each family being DISTINGUISHED Dy Geu9
tie CARBOHYDRATES Now. among the properties which
thus characterize particular families atoms there ono
of which the knowledge gradually WORKED out py the
abOrs OF immense number OF INVESTIGATORS must ge
admitted TO constitute OF the most important addl-
tons ever made to our knowledge OF these little MASSES
will endeavor TO explain II to You by slnBe e1alnPe
An Of chlorine is able TO combine with one atom OF
hydrogen or one atom Of potassium; Dnt ~ canRSa
combine with two atoms An atom OF OXYGEN On .ne
hand, combine with two atoms OF hyurogeh or
with TWO atoms Of potassium or Win one s'o ga, r. n
combination with atom OF hydrogen OF OF potassium
solely Again an atom OF nitrogen Is s an :" atom Of
carbon combines with four OF hydrogen Other atoms
are classified from their resemblance 10 these respect
iyey as Monads Dyads Triads, Tetrads &c. The ad-
In knowledge Of the order In which atoms are
arranged in moecule was consequent upon the Tore
Study Of the laws governing atomic exchanges in,
dcates also relation between them ana the units OF
| time absorbed in the formation OF new products
Suppose that to determine by experiment the
erais and the number Of molecules of the products in
mixture the composition Of which remains constant,
rias as OF producis what would this meant Why. II
couples Of materials only effect In the unit OF
time many exchanges every one couple OF products,
couple Of materials is only exchanging ha as last
every couple OF products.
In fact You perceive that determination OF the pro
portion In which the substances are present In such
mixture will give OF the relative veocitfes
| OF those particular atomic motions; and we may thus
express result The force OF chemical combination Is
inyersey proportional 10 the number OF atomic inter
/ changes
cannot quit this part of subject without auding
20 the fact that some few chemists Of such emineDce az
10 he entitled 10 the most respectful attention. have OF
late years expressed opinion that the idea OF atoms
not necessary for the explanation Of the changes In the
chemical constitution OF matter, and have sought,
as far az possible TO exclude from their Ian
guage any alusion 10 atoms. IL would be out
OF place this occasion 10 eater into any discussion Of
the questions thus raised but think IL right 10 point