Handbook of Solvents - George Wypych - ChemTech - Ventech!

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Fundamental Principles
Governing Solvents Use
2.1 SOLVENT EFFECTS ON CHEMICAL SYSTEMS
Estanislao Silla, Arturo Arnau and Iñaki TuñóN
Department of Physical Chemistry, University of Valencia,
Burjassot (Valencia), Spain
2.1.1 HISTORICAL OUTLINE
According to a story, a little fish asked a big fish about the ocean, since he had heard it being
talked about but did not know where it was. Whilst the little fish’s eyes turned bright and
shiny full of surprise, the old fish told him that all that surrounded him was the ocean. This
story illustrates in an eloquent way how difficult it is to get away from every day life, something
of which the chemistry of solvents is not unaware.
The chemistry of living beings and that which we practice in laboratories and factories
is generally a chemistry in solution, a solution which is generally aqueous. A daily routine
such as this explains the difficulty which, throughout the history of chemistry, has been encountered
in getting to know the effects of the solvent in chemical transformations, something
which was not achieved in a precise way until well into the XX century. It was
necessary to wait for the development of experimental techniques in vacuo to be able to separate
the solvent and to compare the chemical processes in the presence and in the absence
of this, with the purpose of getting to know its role in the chemical transformations which
occur in its midst. But we ought to start from the beginning.
Although essential for the later cultural development, Greek philosophy was basically
a work of the imagination, removed from experimentation, and something more than meditation
is needed to reach an approach on what happens in a process of dissolution. However,
in those remote times, any chemically active liquid was included under the name of “divine
water”, bearing in mind that the term “water” was used to refer to anything liquid or dissolved.
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Parallel with the fanciful search for the philosopher’s stone, the alchemists toiled
away on another impossible search, that of a universal solvent which some called “alkahest”
and others referred to as “menstruum universale”, which term was used by the very
Paracelsus (1493-1541), which gives an idea of the importance given to solvents during that
dark and obscurantist period. Even though the “menstruum universale” proved just as elusive
as the philosopher’s stone, all the work carried out by the alchemists in search of these