Full Idea
The qualities of a mixture need not be those of its ingredients in isolation.
Gist of Idea
A mixture can have different qualities from its ingredients.
Source
Peter Simons (Parts [1987], 6.2)
Book Reference
Simons,Peter: 'Parts: a Study in Ontology' [OUP 1987], p.221
A Reaction
It depends on what you mean by a quality. Presumably we can give a reductive account of the qualities of the mixture, as long as no reaction has taken place. The taste of a salad is just the sum of its parts.