Chemistry Reference
In-Depth Information
In his
Prinzipien der Chemie
from 1907, he (not without conceptual problems
26
)
described the dissolved ions in a solution of (simple) salts as isomers of the
respective elements (e.g., Na
+
/Na and Cl
-
/Cl), and addressed these entities using
the singular form (that is, e.g.
chloride ion
instead of
chloride ions
). In contrast to
the huge amount of empirical results from electrochemistry - to which he had
contributed largely - there was no information available in the field of free radical
research at the time Ostwald wrote his
Elektrochemie
. Hence, he felt justified to
argue against the purely speculative radical concept which had - as far as he was
concerned - by no means led to new knowledge, new research, or new substances.
In his theoretical arguments, Gomberg referred to a submicroscopic picture in two
main respects. Firstly, he was trying to find an experimental proof for a stable
trivalent
carbon atom (after having recognized this very possibility in his attempts
to synthesize hexaphenylethan, as it were). This particular projection of the
elementary distribution to the unobservable particle world was his first aim and to
him it meant a radical status because all organic radicals discussed in the nineteenth
century (e.g., ethyl and acetyl) consisted of trivalent carbon atoms. Secondly, he was
applying the notions
monomer
and
dimer
in a molecularistic sense. These notions
imply a submicroscopic point of view, at least in this case. Although he occasionally
addressed his solid reaction product as “radical”, Gomberg considered - and was
forced to consider by his molecular weight determinations - this solid to be some-
thing assembled from the monomers which he assumed to exist in the dissolved state.
However, Ostwald
s general criticism against any form of speculation regarding
the properties of atoms or molecules does not hold referring to Gomberg
'
swork:
the latter had something substantial in his hands, and he was able to determine some
classical “constants”.
27
Even another classical concept to operationalize the classifi-
cation of substances by Ostwald, the
stuff law
, does not apply easily to radicals.
28
If stuff constants only are obtained with extraordinary high variations (e.g., the
molecular weights), and if these constants cannot be assigned unequivocally to one
entity (e.g., the colored solutions and the uncolored solid) alone, then this
stuff law
does not seem to be in force at all for this example. If a solution of Gomberg
'
s
“radical” is used for some measurement, then something related to but different to the
solid is addressed. In that respect Ostwald was right to point at the similarity of salt
solutions on the one hand and radicals (triphenylmethyl and its “dimer”) on the other,
but his
stuff law
is hardly applicable to radicals.
'
26
Cf. Ruthenberg
2008b
for a short discussion of this episode from the history of the philosophy of
chemistry.
27
The author has not found an explicit reference of Ostwald
'
s to Gomberg
'
s radical. In his
Principles
from
1909
, Ostwald still referred critically to the expression
radical
as a formal and
structural grouping concept without mentioning concrete examples (Ostwald
1909
, 325).
28
Ostwald said that if two bodies have some specific properties in common then all other specific
properties will turn out to be identical, too: “
wenn bei zwei K¨rpern einige spezifische
Eigenschaften ¨bereinstimmen, dann erweisen sich auch alle anderen spezifischen Eigenschaften
¨bereinstimmend.” (Ostwald
1907
, 74-75)
...
