New-York daily tribune., 1855-08-21
AMERICAN ASSOCIATION FOR THE
ADVANCEMENT OF SCIENCE.
fronl Or Own Reporter.

From Our Own Reporter
PRovIDEScr, Saturday. Aug. l5, 1855.
The Association met this morning in general ses-
sion at 10 A. NJ.
An invitation was received from the Local CON-
mitiee TO an excursion down the Bay to Bristol Ferry
where an aboriginal clambske was TO be served up,
und,r the shadow OF Mount Hope, but it was declined
BY tie Association, ss they have so many papers On
hand that no time is TO be lost.
On motion Of Prof. CaswELL i was voted that the
Address Of Prof J. d. Dana be printed in pamphlet
form for distribution.
REpoRr on the recent progress of Organic Chezstry
6y Prof WOLcorT GIBBS.
There are two points of yieS from which the SUBJ
sct may be consderei Tc confne our attention to
positive additions to chemical knowledge or the
development OF general laws. Prof Gibbs chose the
latter.
-Four theories have divided chemists.
l. CoNPOUSD RADIcALs.-Ghis was invented by
Berzelus in 1877, and applied 10 compound radicals
containing carbon ard hydrogen only. II was adopted
by ebig who as umed the existence o. radicals
isining oxygen also. This view was adopted by the
GsmaDs met with favorin England, bu, was received
by few in France. But the researches Of Hoffman on
TIE Ammonies and Ammoniums in which any one OF
the three equivalents of hydrogen may be substituted
by methyl ethyl or other electro-pOstive radicals,
have produced a great change in The views of chem
ists. True. Wariz discovered Mehylamine and hyl-
anime but the generalization OF the theory Of replace
ment of hydrogen bys compound radical Is due to
Hoffman.
lie found that three different radicals may b. sub
stituted ior the hydrogen of ammonia and four in
monum. and still the distinctive properties of the
primitive Substance not altered oy the successive
eplacenent of The hydrogen excepting only in degree
This discovery lCt alternative for the chemist, aud
a genera though not always cordial acquls ,ence, has
taken the place of former hostility. Hoffmans method
of replacing hydrogen u used for studying the mole
cuar structure of natural alkalOlds, but many new
ones have been formed and we have prospect Of ar
ticislly reproducing some OF the most valuable Their
speutic agents possess. H0fmans discoveries
have been supported by the discovery OF Formylanne
and Acetylamine bv ClOes and Ha'anson They lead
us TO suppose that Acety bears the relation to
Fhy that iron has 10 zc. In the isolation Of organic
radicals some progress has been made though Il is In
many cases doubtful TO say the least, whether the sub
starces isolated The radicals themselves or only
bed isomerc with them.
III. CoSJUGATIoS or the union Of body with
another body b, of such nature thar the properties
OF are thereby changed in degree but not in kind.
There are three foms, conjugate radicals acids, and
bases the first in fact the pnmltives OF the other
two and have beer most studied. The starting point
of this theory il the memoir OF Bunsen on cacOdy
regarded now % q cOnjunct OF two equivalents oi ne
thyl with ole of arsenic The stannethyl OF Frank
land is good example oi this class. Most o. them
can be obtained IN a free state.
I'LL HONoLOGIsM.-NO theoretical yiewe have done
20 much 70 make organic chemistry science the
discovery of the principle Of tomoogy by Gerhardt.
IL shows that series OF bodies between which there
exists constant difference of constitution, analO-
eous in chemical properties and relations. This
siant difference is C2H2, or some multiple OF that
quantity. Bodies related are said 10 be bOmoogues.
II is sufficient to know the general properties OF one OF
a series TO know those OF all i's homoogues when
correspond though not in degree. The chemist viii
understand this by comparing the bodies represented
by the following symbols;