Chemistry Reference
In-Depth Information
Despite the fact that many factors do not cease to change, the mixture of bodies
is gradually separated, the polarity of solvents is modulated, the flow rate can
evolve as well as the temperature, and so on, but one thing must remain inside
strict boundaries: The concentration of the bodies under study.
The ceteris paribus
clause is about the possibility for a particular determination of a quantity to belong
to a very short confidence interval
,
notwithstanding all the fluctuations which
continue to occur
. This result is relative to the complex {apparatus-methods-
bodies-associated milieu-devices} at stake. The same apparatus is not prepared in
the same way according to the nature and the quantity of the body under investi-
gation. The method of analysis is not used in the same way if the triad composed by
the apparatus, the bodies, and the associated milieu has changed. In this context
of activity, methods can never be blandly detached from the content it yields.
The association between the apparatus and the method depends on the associated
milieu, the device, and the bodies under study. The five elements of the complex are
co-adapted to one another. If chemists change a factor, for example a type of
column, the mode of injection of the solvents, the quantity of product, the matrix
from which it is originated, the preparation of the sample, the detector, among other
possibilities, they will have to resume the process of co-adaptation from the very
beginning because the complex does not work anymore. For example, they know
that a method validated for titrating pesticides in a certain type of lettuce cannot be
used for quantifying the same pesticides in other varieties such as Batavia or
escarole originated from the same agricultural site. In this case, the difficulty will
be to choose a standard, namely a blank matrix, with
enough
representativeness in
order to encompass the different empirical determinations available.
In short, chemists must stabilize
a specific domain of application
of the whole
complex in order to determine a quantity of a particular type of body within certain
limits imposed by standards of normalization and laws. The sentence “all things
being equal” encompasses the co-adaptation and the channeling of multifarious
fluctuations which, in turn, leads to the very possibility of making holistic infer-
ences as regards the performance of the whole complex within the normative
framework of a quality control process. The
ceteris paribus
clause is not illusory
in the domain of chemistry but refers to a new type of “nomological machine,” to
use Nancy Cartwright
s turn of phrase, that is
'
a fixed (enough) arrangement of components, or factors, with stable (enough) capacities
that in the right sort of stable (enough) environment will, with repeated operation, give
rise to the kind of regular behavior that we represent in our scientific laws. (Cartwright
1999
, p. 50)
The idea of nomological machine is interesting for our purpose insofar as it
revolves around the key notion of co-stabilization. We nevertheless prefer to use
the word preparation instead of that of arrangement. We also prefer to focus our work
on the notion of a complex which displays certain type of
affordances
in the context
of chemistry because the mode of access often takes part in the constitution of
what chemists are studying and talking about. Following Bachelard
snotionof
'
phenomenotechnique
(
1934
), we assert that the question is not one of reality and
'
'
