New-York tribune., 1874-02-10
NEW PUBLICATIONS
,,onrsN MOLECULAR CHEMISTRY,

-, Professor of Chemistry in Harvard ohl-
,,,s;r,, is the first American contribution to 'n'
International Scientific Series" and more at
,raetiye piece Of work in the way OF popular eAPo-
,t,on npon difficult subject has not appeared ior
lono time 1t not only well sustains the character
"a ,,s volnmes with which il is associated, but JUS
D,oduetion in European countries VIII DE an hohor
=, American science II is, moreover, In an emlneh'
degree timely for between the abandoniheho VI i'S
.ld views and the bewiderment caused by the new,
chemical science was getting INTO deihorahIeu
-ai,;on A work was therefore greatly needed
hat should relieve the discomfort OF transition, ana
l,dce over the gulf between the old order OF ldeas
and those which are TO succeed them. TroleSsor
Cooks compendiOus contribution 10 the present
.,iCencies of chemical literature Will give 'he
.tndents Of the science exactly the help they need
and pass them over by an easy and pleaSanI route
into the new realm Of chemical philosophy. The
ap,hor has taught the new chemistry in Harvard
University for several years, and has published the
hest collegiate textbook upon the new method that
has vet been offered 10 the scientific world But he
saw that this was not sufficient, and that the dis
tnctvely new features of the subject required to be
separately dealt with in a form suited 10 general
readers. He accordingly prepared course OF
lectures which were delivered before the Lowell
Institute. and received with great approval by the
audiences which listened to them, and having thus
subIected his mode Of presenting the subject 10 the
test Of popular criticism he has carefully revised
his lectures and brought them ont In the present
volume. II was not possible for bm 10 DO a more
important scientific work. For while chemistry had
reached a sort of crisis in its development that
threatened 10 embaTass and obsruet the study TINS
Opportnne book will not only facilitate the students
course but cannot fail to exert much influence IN
stimulating the general cultivation of the science.
Ofall modern sciences chemistry is perhaps the
most progressive. We are in the habit OF dating ITS
rise from the fan of alchemy. about hundred years
ago But as Liebg has shown, the idea of the ex-
tremey modern origin of this science is an illusion due
10 the fact that the French chemists toward the close
of The last century introduced new language which
formed a kind of break, beyond which modern
students are not in the habit of passing. Yet for
hundreds of years previously, and with all KINDS OF
crude and wild speculatiOns the alcbemsts accumu-
lated a large body of observations and experiments
which formed the basis Of the science and to which
the French chemists applied their new terminology.
OF course with the epoch of LavOisier, chemical
method became more strictly lnductive and expert
ments more exact while the theories established at
that time gave "a renewed and powerful impulse 10
the whole subject. The progress of chemistry has
been twofold, experimental and theOTetic; but while
experimental progress has been steady and rapid,
theoretc progress has been irregular and by epochs
hundred years ago the science consisted of a COM
paratively limited body of facts which could be ac-
,uired by single minds devoted TO the subject but 1t
Las now branched out into SO many divisions that
chemists have been compelled TO become specialists
and can then hardly keep pace with the progress i'll
their own departments. We have now the great
divisions of pneumatic chemistry, mineral chem
istry vegetable chemistry. animal chemistry, tox-
Cological chemistry, Photographic chemistry, and
even celestial chemistry, while the applications OF
the science the processes Of the arts have become
60 numerous and important that an operative
chemist is indispensable appendage 10 many
manufacturing establishments These are the great
results of the steady and continuous progress of ex
perimenta research in which there has been and
will be no interruption.
But when il comes TO the Interpretation of the
facts 20 their classification and theoretical eXplana-
tOn, that is the putting them IN such relations that
they can be most efectually grasped and welded by
the thinker the progress conforms TO different law.
Something like a system is here required and from
The nature Of the case this only express the
chemical attaiDments of gwen time. The period
of alchemy was time of cropping aud blind effort
for lack of any coherent and rational views by which
The facts of experiment could he connected and in
teTpreted. Stahls theory of pblogstOn the first
serious attempt TO bring into relation wide series
of chemical changes With the discovery Of oxygen,
aud better understanding of the process of com
bustiOn the era of phlogistOn terminated, and
wider and more consistent theory took its place
This is known the binary dual system of chem
istry in which bodies were conceived to combine IN
pairs An acid was held to result from the union of
a simple body generally non-metallc) with oxygen
while an oxide resulted from the combination with
ame'al. In the same way salt was produced by
the union of an acid with oxide or base and this
pairing of doubles supposed TO represent its
stitution. The chemical nomenclature was con-
structed upon this ideaOf dualism and the view
subsequently confirmed by electro-chemistTy, by
which bodies were decomposed into pairs that ap-
peared at opposite poles of the battery during cleo
trolysis The device Of the chemical notation intro
duced by Berzelius in 1916 in which the elements
wererepresented by symbols gave rise to formulas in
which the binary theory brought out with great
clearuess. But while the dualistic system well
established in inorganic chemistry, and seemed suf
fcent 10 account for all its facts il not easy TO
bring the complexities of organic chemistry into
harmony with it, There were organic acids organic
bases, and organic salts which cOnformed to the
laws OF binary union 3ut there were other changes
and relations which could not be readily resolved in
this way: Vet Berzelius made it his great task TO
show that the theory Of pairing was sufficient
for organic chemistry. Compound organic radicals
were discovered which played the part of simple
elements. vet these also were suboTdinated TO the
binary system. But the theory was here insult
cient. New facts appeared which were more and
more opposed 10 the binary explanation and school
arose led by Dumas, Laurent, and Gerhardt, which
took a new view of the constitution Of organic
bodies. The dual system thus broke down in or
ganic chemistry and the theory that grew up in its
place has extended backward into mineral chem.
istry. and is now accepted as applicable to the whole